User Manual for the Devil Fish MIDI In system V1.0.4
Contents
1. MIDI In Sync system The MIDI In system cannot sense whether anything is plugged into the Sync socket to open the switches which disconnect the TB 303 s internal Run Stop and Tempo Clock circuits from pins 1 and 3 of the socket respectively Nor can it sense the state of these pins to know if an external signal such as by a special lead carrying both MIDI and Sync is driving the pins So the MIDI In system cannot sense whether the TB 303 s CPU is playing a pattern driving Gate Accent etc However the MIDI In system can drive positive voltages about 5 volts onto the pins 1 and 3 Run Stop and Clock respectively of the Sync socket This means it will drive the TB 303 s CPU and any external lead which may connect these pins to other devices Assuming no external signal is driving these pins and assuming that a normal lead has been inserted far enough to activate the switch which disconnects the internal Run Stop and Clock circuits then the MIDI In system is free to drive the pins according to the bytes it receives from MIDI if the parameter 7 Receive MIDI Sync is set to 1 On which it is by default However if there is some other source of Run Stop or Clock such as due to the Sync socket switch not being properly pressed meaning it does not disconnect both the Run Stop and Clock drive signals from the TB 303 s internal Temp oscillator and Run Stop flip flop or some other signals being applied to the pins then the MIDI In system2. cc ceeeececeeeeeee ee eeeeeeeeees 5 Blue LED MIDI activity display and how to disable it 0 cccccccccceeseeeeeeeeeeeeeeeeeeeeeeeeeeeeeaaeeeeeeeees 6 Turning on and off the reception of MIDI Notes and Control Changes eeeeeeeeeeeeeeeeeeeees 6 Altering the value of a parametel tienen EEEE 7 3 User Definable Parameters cccceccesseeeeeeeeeeeeeeeeeeseeeeeeeeseeenecuesneeeseeeseesseaseeessenneeeees 10 4 Interaction between the MIDI In system and the TB 303 Devil Fish cssseeeeee 11 Thestandard TB 303 sursson enn aeir wedi EE E E E EE EEEE EE EE HEN EN deere 11 Devil Fishi CV IMr oa eddie ceed dca sce aa i ae ene 13 ES Will Fish GAUS eo cases eect a E eee tae ne seers se nce oe Se eee 14 BSN FS Ma Nas sc cs Leaked cc cbt pas tas pasate Sous ene esos a ee 15 Devill FISM ACCOM iina tees Lav apet eevabeagneeantenvenaweteannuasas feta aa i 15 MIDI In Sync SY SUSI cc ccoidsdeadantiidcentad hiadattcnkamnsaunendtasagnendiudidaginndbiadiauesdiessinnduaunsdasaantuannemandiiauionsitan 16 5 Details of features and User Definable Parameters cccccccceeeeeeeeeeeeeeeeeeeeeeeeeaeeeeeees 17 Monophonic reception of Multiple notes 2 2 2 ccc cece cece eee e ee eee eee EE EEE EEE EEE EE eet ee eee eeeeeeeettEeE 17 The Blue LED Mewar ne enti kane et a Nee e tener O teehee ee et ene ne met ee ee 17 MIDI Receive Channel parameter 0 cece cece e cece cece ee ee eee EEE E
3. or Increment when it is at its maximum the value will not change and the Blue LED will flash for a longer time If you changed the value of the parameter to a new state then the Blue LED will flash for a short time Changing the parameter has immediate effects on the MIDI In system Furthermore changes to some parameters cause specific actions such as clearing received notes Accent Slide etc if the MIDI receive channel is changed These are explained in the detailed information below on each of the parameters The changed parameter will not be written into non volatile memory unless the next step is performed If you wish to abandon whatever change you just made to the parameter turn the machine off Turning it on will restore the value to whatever was stored in non volatile memory Saving to non volatile memory and returning to normal operation Whether or not you have altered the value of a parameter in the step above to return to normal operation you must perform the following procedure which also writes the new value or the original value if unchanged to non volatile memory Press and hold both the BACK and TAP buttons until the Blue LED flashes with a distinctive double flash pattern This will involve holding both buttons for about 3 seconds When you have pressed and held them for long enough the Blue LED will flash with a distinctive double flash pattern This is the signal to Release both buttons after whi
4. 19 For reference here is how this range of Control Change controller numbers is commonly used These are just the names of functions of other synthesizers which may transmit various controller numbers These functions have nothing to do with the Devil Fish MIDI In system Those marked with are common Controller Function number Modulation Wheel Breath Controller Foot Controller Portamento Time Data Entry Slider Volume Pan Expression Effect Control 1 Effect Control 2 lider lider lider lider General Purpose General Purpose General Purpose General Purpose OMDAINHDOBPWNFOWO OND SP WN EE NNWNW A WN ER Slide on Tied Notes parameter 4 When this parameter is set to 1 which is the default Slide will be turned on when a second note is played while one is already active When it is set to 0 this will not happen the CV to the VCO and the CV Out socket will change immediately to the new note s voltage Changing this parameter to 0 will end any Slide which is on at that time due to tied notes 22 Sustain Slide Controller parameter 5 When set to 0 the default this feature is disabled When set to 1 to 19 and a Control Change message for this controller number is received on the currently selected channel parameter 0 then the value of this message will drive Slide and or Sustain Gate On even if there is no note currently playing Howe
5. A workaround is to use a special lead with the centre pin cut off or disconnected at the TB 303 Devil Fish end Any potential ground loop problems are likely to be less serious than if Pin 2 was directly connected to the TB 303 Devil Fish ground The 22 ohm resistor which is part of the original TB 303 circuitry is low enough to connect the TB 303 Devil Fish ground to the ground of an external Sync source if there was no other form of connection between these two grounds However the 22 ohms is high enough that it is likely to have not such a strong ill effect in the event of a ground loop or other such ground noise problem The subject of ground noise problems is extensive and difficult to comprehensively describe MIDI In whilst still using the internal Tempo Clock and Run Stop If a MIDI lead s plug was modified so as to cut away the metal of the shell where the locating ridge is the top of the shell when it is plugged into the TB 303 Devil Fish then MIDI information can be sent to the MIDI In system without activating the Sync socket switch which disconnects the internal Tempo Clock oscillator controlled by the Tempo knob and the internal Run Stop flip flop controlled by the Run Stop button 25 This would enable MIDI control of Note Gate Slide Accent and Filter Frequency via MIDI while the TB 303 s internal sequencer is operating from its internal Tempo Clock oscillator It would also be possible to play notes
6. In socket Isolation of MIDI Pin 2 The TB 303 s Sync socket uses Pin 2 centre for ground via a 22 ohm resistor In most MIDI devices this pin of the MIDI In socket is not connected to anything It is always connected to ground on MIDI Out sockets for the purpose of grounding the shield of the cable The MIDI data lines Pins 4 and 5 on either side of the centre pin drive the MIDI In device via an opto isolator to avoid problems with ground loops which can cause background hum etc An opto isolator consists of a Light Emitting Diode driving a phototransistor in an on off manner The serial data bits of MIDI are conveyed by light rather than by electrical current or any form of direct electrical connection This standard MIDI arrangement of having Pin 2 being a non connection means there is no electrical connection between the MIDI Out device and the MIDI In device other than the current flowing between pins 4 and 5 through the LED of the opto isolator This is not a direct electrical connection between the sending and receiving machines so the MIDI cable connection cannot cause any ground noise problems With the TB 303 Devil Fish with MIDI In there will be no such electrical isolation between devices due to the 22 ohm resistor between pin 2 of the Sync MIDI In socket and ground so there could be some electrical noise particularly if the driving device is a personal computer which are notorious for generating electrical noise
7. Thru The existing DIN socket is used for MIDI In but it can still be used for Sync when not used for MIDI In The system uses the TB 303 s internal Digital to Analogue Converter DAC so the control voltages and therefore oscillator pitches are identical to those produced by the internal sequencer User Definable Parameters are altered via the BACK and TAP buttons with status indicated by a new Blue LED which shines through the same e in the Devil Fish logo as the Red Gate LED The values of the user definable parameters are stored in non volatile memory which does not depend on the TB 303 s C cell batteries So these settings remain after the machine has been turned off and on The system receives Note Commands and some Control Change Commands on a single user definable MIDI channel It also receives MIDI Sync Start Clock Stop and Continue The system ignores all other MIDI messages Brief descriptions of the system s capabilities are as follows Notes The full 4 octave range of the TB 303 s internal sequencer is received with the C on the left of the TB 303 keyboard in Pattern Write mode 2 Volts corresponding to MIDI Middle C note number 60 In addition 3 additional semitones below and above this range are also received although the accuracy of the TB 303 s VCO may not be ideal at these voltages The lowest MIDI note number received is 45 A1 0 75 volts 3 semitones below the internal sequencer s lowest C and the
8. an OR arrangement of the above three signals with its own Gate signal The MIDI In system cannot turn off the Gate if it is turned on by any of the above If the TB 303 s CPU was turning the Gate on continually the MIDI In system would not be able to make it go on and off If the MIDI signal contains no Sync Start Clock etc this is unlikely to occur because plugging a lead into the Sync socket will open the switches and disconnect the TB 303 s internal Run Stop signal from pin 1 and therefore from the Run Stop input of the CPU This will cause the TB 303 s CPU to deactivate its Gate signal However if the MIDI lead was only partially inserted or was modified so as not to activate the switch then the TB 303 s CPU could be driving Gate whilst the MIDI In system is trying to turn Gate on and off This might be musically useful but is more likely to be troublesome For further discussion see Section 6 below With an ordinary MIDI lead properly inserted there could be a situation in which the TB 303 s CPU is activating Gate at the same time as the MIDI In system is trying to play notes by activating the Gate This occurs when these three conditions are true 1 The MIDI In system is configured to receive MIDI Sync which is the default arrangement 2 The MIDI signal includes Clock bytes and at least one Start or Continue byte which causes the MIDI In system to turn on Run Stop pin 1 of the Sync socket and as an input to the TB 303 s
9. highest is 100 E6 5 333 volts 4 semitones above the internal sequencer s highest C when the pattern is transposed upwards by 12 semitones A transposition of 24 semitones can be applied to the MIDI note numbers before the notes are played within the above range There is no pitch bend facility Accent Accent is turned on according to the note s Velocity being above a threshold The threshold is a user definable choice of one of four preset values Slide Slide can be turned on for tied notes where one note starts before the last one is released Slide can also be turned on via MIDI Control Change AKA MIDI Controller 65 Portamento or by a user definable Control Change number which also drives Sustain Gate Sliding slewing of the DAC voltage slowly from the previous pitch to the new pitch is a separate function from keeping the Gate on between what would otherwise be two separate Gate pulses for two separate notes Gate Sustain In addition to normal Gate operation from the received MIDI notes Controller 64 Sustain or Hold can be used to independently turn on the TB 303 s Synthesizer Gate Another user definable MIDI Controller can also turn on Gate and or Slide Filter Frequency A user definable Controller can be used to drive the Filter Frequency over a range of about 5 octaves in a similar manner to the Devil Fish Filter CV In Socket This MIDI control of Filter Frequency adds to rather th
10. or on whatever master sequencer the Devil Fish is synched to in order to stop the Pesky C4 note and necessarily play the first note of the current pattern for a fraction of a second 27 8 Firmware version history e 1 0 0 2004 12 09 First version only one machine still has this e 1 0 1 2004 12 22 Fixed a bug which was discovered in V1 0 0 in the saving of a changed parameter value to Non Volatile Memory e 1 0 2 2005 02 16 Fixed potential problems when machine is turned off then on again quickly Previous versions did not have the PIC Brown Out Detector enabled and sometimes the PIC would wake up in a strange state On some occasions the MIDI Receive Channel parameter was corrupted to be 255 Most easily fixed by going Up one to 256 0 which is MIDI Channel 1 Turned on the Brown Out Detector which stopped these problems as far as I can observe and moved the parameters up in EEPROM so they do not use location 00 which may be more likely to be corrupted than other locations e 1 0 3 2008 01 01 Added a function to the Turn Off reception of MIDI notes and controllers command which stops receiving MIDI In Sync and resets the Run Stop and Clock drive to the TB 303 s Sync Socket and so to its Internal Sequencer and front panel LED The last Devil Fish to use this version was modified in February 2013 e 1 0 4 2013 12 23 Fixed bugs and changed capabilities with respect to V1 0 3 O Changed the threshold voltage for the
11. takes for the Blue LED to stop flashing which will be about 4 seconds While the two switches are both pressed the Blue LED will flash repeatedly very quickly After about 4 seconds the flashing will stop and the Blue LED will turn ON continually Release both switches The Blue LED will turn OFF b select Parameter 0 MIDI Receive Channel to edit Since this is Parameter 0 there s nothing to do c alter the value from 1 to 5 Increment the parameter Press and Release the BACK button Increment the parameter Press and Release the BACK button Increment the parameter Press and Release the BACK button Increment the parameter Press and Release the BACK button The Blue LED will flash briefly once for each of the above actions except when the parameter has reached its maximum value If you are unsure of the MIDI Receive Channel number when you start this procedure you can decrement it to its minimum value of by pressing and releasing the TAP button until the Blue LED flashes for a longer time which indicates you have reached the minimum value for this Parameter Then you can press and release the BACK button 4 times to increment the value to 5 d write the new value to Non Volatile Memory so it will be retained even after the machine is turned off and on again Press and hold both the BACK and TAP buttons until the Blue LED flashes with a distinctive double flash pattern This will involve h
12. will not be able to reliably drive these pins The drive for each pin is 5 volts via a diode and 1k resistor This should protect the MIDI In microcontroller from shorts or externally applied positive voltages but be sure not to apply negative voltages or any static electricity spikes to these pins 16 5 Details of features and User Definable Parameters Here is a complete description of the operation of the MIDI In system Please refer to the table on page 10 which lists the User Definable Parameters Monophonic reception of multiple notes The Devil Fish modified TB 303 is a monophonic synthesiser but MIDI is a polyphonic interface There are several ways a monophonic device such as a MIDI to CV converter might be designed to choose which single pitch to play when multiple note on and note off events are received Common approaches include high note or low note priority where the highest or lowest note of the currently active notes is the one which drives the monophonic synthesiser The Devil Fish MIDI In system uses a most recent note priority system with a ten deep internal stack of the most recently turned on notes which are used if the currently played note is turned off This means that up to ten notes can be active at once and as they are released the MIDI In system will back track through the list of currently active notes selecting the most recently started when more recently started notes are released The Blue L
13. 0 setting of parameter 6 Accent Velocity Threshold from 64 to 65 V1 0 3 would play an Accented note for a MIDI In note with velocity 64 and above However 64 is the usual velocity to for notes which come from a non velocity sensitive instrument Fixed the 1 semitone offset bug The pitch played is now exactly that of the MIDI In note message according to the Transpose parameters The highest voltage output is now 5 333 volts for MIDI Note Number 100 E6 Removed the facility mentioned on page 8 of the MIDI In 1 0 3 manual introduced in V1 0 3 for turning off Sync reception with the Turn Off MIDI reception of Notes and Controllers I introduced this to solve a problem which may occur if the MIDI In lead is unplugged while the Devil Fish MIDI In system is running from MIDI Sync this state would persist preventing the Internal Sequencer and the drive to Sync Socket from being controlled by the Run Stop button until either Sync reception was turned off parameter 7 page 11 or the machine was turned off and on again This facility works as intended providing an easy way to turn of a no longer wanted Run state However this facility had the potentially unwanted effect that it was no longer possible to alternate the control of the DAC and therefore the Devil Fish synthesizer between the Internal Sequencer playing from MIDI Sync and the notes being received on MIDI In since turning off MIDI In reception would also turn off the Run sta
14. 19 to 2013 09 23 Improvements thanks to proofreading and suggestions by Lincoln Webber 2013 10 23 to 2013 11 03 Expanded the list of differences between V1 0 4 and previous versions and added note that this manual doesn t yet cover these changes On 2013 11 03 I added the section on the Pesky C4 note 2014 01 26 Minor improvements to the text 29
15. CPU and to provide Clock pulses on pin 3 and also to the CPU 3 The TB 303 is currently set up to play a pattern or track such that the pattern it plays contains some notes In the typical situation with an external MIDI sequencer which puts out Sync bytes there are two ways of avoiding this problem of the TB 303 CPU driving the Gate when you really want to be controlling the Synthesizer entirely from MIDI Either of these approaches will solve the problem 1 Disable the reception of MIDI Sync Parameter 7 in the User Definable Parameters section above or 2 Make sure the TB 303 is in Pattern Play or Write mode on a blank pattern 14 Devil Fish Slide There are two signals which can turn on the Slide circuit This is not the same as turning on the Gate to tie two otherwise separate periods of Gate on into a single period The TB 303 s CPU when playing two notes with Slide does this leaving the Gate on as it changes the DAC voltage whilst turning on the Slide signal to cause the resulting voltage to the VCO to slew slowly 1 The TB 303 CPU s Slide signal 2 The Slide signal which results from the Devil Fish Slide input socket having more than about 2 3 volts applied to it The MIDI In system can override the TB 303 CPU s Slide signal and the Devil Fish Slide input socket When the MIDI In system is driving the DAC it doesn t matter whether the TB 303 CPU or the Slide input socket is driving the Slide the
16. ED The MIDI In system has a Blue LED mounted to shine on the Red LED in the e of the Devil Fish logo This is a conventional Blue LED which is brighter and somewhat more aqua LED than the Blue LEDs which can be installed in the TB 303 front panel The new Blue LED may not be clearly visible in very bright lighting such as sunlight but should be clearly visible in most other circumstances If the machine is turned on with the BACK button pressed the LED will light in a continuing sequence of pulses showing the three digit version of the MIDI In and Out system s firmware This is described on page 5 The primary purpose of the Blue LED is both to indicate various states of the Front Panel system and to indicate the successful reception of a MIDI In Note or Control Change message The signal which drives the Blue LED may cause slight interference with the Audio Out signal so for critical recording purposes involving MIDI In Note and Controller messages it may be best to turn this off as described in the next paragraph When no front panel operations are in progress the LED indicates successfully received MIDI messages unless this Blue ED reporting of MIDI In activity is turned off by turning the machine on with the TAP button pressed and the BACK button not pressed When the Blue LED is enabled when the machine is turned on without holding Back or Tap there are three types of flash for three types of message The fi
17. EE EEE EEE EEE EE EEE eet EE EE EEE EEE EEE 18 Transposition parameters 1 and 2 eect ee cece eee e cette eee eee eee eeeeeeseeaaeeeeeeeeeeessaeeeeeeneeseeeees 20 Filter Frequency Controller parameter 3 00cccccccccce cece eeeeeeeeeeeeee eee eeeeeeeeeeeeeeeseeeeeeeeeeeeeeeeeeaaaes 21 Slide on Tied Notes parameter 4 c cece ccccc cece eee eeeee ee eeeeeee tesa eee eeeeeeeeeeeeeaaaeeeeeeeeeeseeaeaaaeeeeeeeeeees 22 Sustain Slide Controller parameter 5 cccccccccceeeeeeeeee cette eee e ee eeeeeeeeeeeeaaaeeeeeeeeeeeessanseeeeeeeeeees 23 Accent Velocity Threshold parameter 6 00ccccccccec cece eeeeeeeeee cette eeeeeeeeeeeeeeeeesaaeeeeeeeeeeeeeeeseaaes 23 Receive MIDI Sync parameter 7 ccccccccccceeeee cece cette eee eeee eee e tessa eae EErEE eeeeeeeaaeeeeeeeeeeeeeeeeaaaes 24 6 Advanced use of the Sync MIDI In socket ett rr eee reer eee e eee eeeeeeeeeeeeeeeeeeneneeee 25 Isolation of MIDI Pin 2 ii ci2iccntessiciniiciascescedeccadssteioaiadidieaiasiediadadlisendavassocadeusasusodidioaiiew wadesseeeisteieies 25 MIDI In whilst still using the internal Tempo Clock and Run Stop ccccceeeecceeeeeeeeeeteeeeeeeeees 25 Receiving MIDI Sync and driving external devices eee e ee EEEren 26 7 The Pesky C4 Note in Pattern Play MOC er eee reer reer ee eeeeeeeeeeeeeeeeeeeeeeeeees 27 8 Firmware version MIStOlY ove ssdetececscencensnhndedesatete sere Gtcetste
18. MIDI In system will control Slide irrespective of these This overriding begins with the first note played by the MIDI in system in response to MIDI In The override is not activated simply by the MIDI In system being ready to receive notes A note must be received first Once this happens the MIDI In system will control Slide according to Tied Note Slide and the Slide Sustain Controller until the reception of notes is turned off by holding down the BACK button and pressing and releasing the TAP button Devil Fish Accent There are three signals which can turn on the Accent to the Synthesizer which also turns on the Devil Fish s Accent Out socket 1 The TB 303 CPU s Accent signal This could be stuck On if the CPU s sequencer function is stopped in the middle of a pattern with an accented note or perhaps if it is ready to play a pattern which starts with an accented note 2 The Accent signal which results from the Devil Fish Slide input socket having more than about 2 3 volts applied to it 3 The Accent Button being pressed The MIDI In system overrides the TB 303 CPU s Accent signal When it is driving the DAC as described in more detail in the paragraph in blue immediately above it doesn t matter what the TB 303 s sequencer is doing The MIDI In system s Accent signal is ORed with the signals from the Accent In socket and the Accent button to produce the final Accent signal for the Synthesizer and the Accent Out socket 15
19. REAL WORLD INTERFACES User Manual for the Devil Fish MIDI In system V1 0 4 Robin Whittle 26 January 2014 www firstpr com au rwi dfish There are separate manuals for the V1 0 0 to V1 0 3 MIDI In systems and for the MIDI In and Out system Contents 0 Quickstart and default behaviour visccsvesecdeeeieteec eu eee es teincistiecte he ea 2 1 Overall GESC MUO MW irseccnreencscoscecectanazimancuscscsacveacs cpcaceasesacsaes esminsasnene sansncaupaueceetususeaceeaniatetsneenes 3 AOIN E E E E E eee eee 3 PACCEMM ea a E E E E etoese ae 3 Slide erase e E E E O E ea beaten E E E A R 3 Gate SUSLAIN 6 save desis seen eee BENE AE aAA ESSE ia EEE aE E SE eE eina a 4 Riter FREQUGICY eerst a ari a e a a r E EE 4 SVC MIMOM IS AMON esa E E RE A E RE E e E E A E A A E 4 Firmware updates via installing a new microcontroller Chip ccccecceecceeeeeeee ee eeeeeeeeeeeteeeeeaeeeees 4 The Sync MIDI In socket is not an ordinary MIDI In socket 0 0 cceeee cece eee eee eee eeeeeeeeeeeeeeeeeeees 4 2 MING Front Panel geez teasers seca uteccec eesti wee laa ede aaaea E Eaa teers teeter cchimtoaceee 5 Initialising the Parameters bs ce acivancacdoeesdacssenanenates lt tuvedeussedasealniavtus aE EREA EEE EE EAN ET EEO 5 Firmware version display ccccceeeccceee cece ee nenee cece eeeeee ce aeeeeeeeeeeeeeesaaaeeceeeeeeeesaeeaaeeeeeeeeeeeeeeaaeneeeess 5 MIDI Notes and Control Changes are received by default at power ON
20. an replaces or overrides the control exerted by the Filter CV In socket and all the other internal signals which affect Filter Frequency Synchronisation The system receives MIDI Sync Start Continue Clock and Stop to drive the TB 303 s internal sequencer With a suitable lead such as the Sync Lead see sync lead page on the Devil Fish website the MIDI In system can also produce DIN Sync for external devices in response to these received Sync messages Below is a guide to using the Front Panel for setting various parameters and a detailed discussion of all the features and parameters Firmware updates via installing a new microcontroller chip The MIDI In microcontroller PIC16F870 for V1 0 4 is a 28 pin DIP device which can be replaced with a new one containing later versions of the firmware to fix any bugs and to implement new features This involves completely dismantling the TB 303 Devil Fish and reassembling it so this should only be undertaken by an experienced technician The microcontroller is small and easy to send in the post The Sync MIDI In socket is not an ordinary MIDI In socket The Sync MIDI socket of the Devil Fish with MIDI In is not an ordinary MIDI In socket The two outside pins carry Run Stop and Clock This means that devices such as the Evolution 225C and no doubt other keyboards from this company www evolution co uk should not be plugged into the Devil Fish except with a lead which does n
21. but this would take control of the TB 303 s DAC away from the TB 303 s CPU Then only the TB 303 CPU s Gate output would affect the synthesiser since the MIDI In system takes full control over Accent and Slide It would also be possible to receive MIDI Sync in this mode but the results are likely to be confusing The final Run Stop to the Sync socket and the TB 303 s CPU would be the TB 303 s Run Stop ORed with the Run Stop output of the MIDI In system Likewise the final Clock would be an OR of the internal Tempo Clock and whatever Clock pulses were generated by the MIDI In system in response to MIDI Clock commands In principle there might be some use for such an arrangement but it would result in erratic timing for the TB 303 s internal sequencer One potential use might be to use Start and Stop without any Clock commands which most sequencers would normally generate via MIDI purely to start and stop the TB 303 s internal sequencer with its tempo being controlled manually with the Tempo knob Receiving MIDI Sync and driving external devices With an external box or a special lead it is possible to achieve the following 1 A separate MIDI In socket which connects only pins 4 and 5 to the TB 303 Devil Fish s Sync MIDI socket This solves any ground noise problems created by the noise on the ground of the MIDI Out device 2 One or more sockets or 5 pin DIN plugs which take the pins 1 2 and 3 Run Stop Ground and Clo
22. ch the Blue LED will turn OFF and the MIDI In system s Front Panel will be in normal operation mode 3 User Definable Parameters Turning on and off the reception of Notes and Control Changes is described on pages 6 and 7 The other parameters are accessed and altered by the procedure described immediately above Altering the Value of a parameter on pages 7 8 and 9 The following table lists all the User Definable Parameters by their names range of values default value and a short description of their function Each parameter is discussed in greater detail in Section 5 below Page numbers for these explanations are in blue in the left column Name of parameter More details on page xx MIDI Receive Channel 18 Transpose Enable 20 Transpose Amount 20 Filter Frequency Controller 21 Slide on Tied Notes 22 Sustain Slide Controller 23 Accent Velocity Threshold 23 Receive MIDI Sync 24 Parameter number Range amp number of presses default of the BACK button to select this parameter before pressing TAP 0 None just press 1 16 1 TAP 1 0 2 0 2 0 24 12 3 0 19 1 4 0 1 1 5 0 19 0 6 0 3 0 7 0 1 1 Function Red bold default Selects which channel will be used for receiving Note and Controller messages 0 No transposition 1 Transpose Up 2 Transpose Down Number of semitones to transpose the MIDI Note number up or down before playing it on th
23. ck signals from the Sync socket to one or more other devices Since one Sync output device can drive practically any number of Sync input devices a dozen or a hundred it depends on their input impedance and since there is no need for electrical shielding of these cables or concern about their length tens or hundreds of metres should be fine a suitable box with sockets or flying leads could be created to extend the usefulness of the MIDI In system We can supply such a lead Please see the sync lead page at the Devil Fish website 26 7 The Pesky C4 Note in Pattern Play mode There is a pesky combination of circumstances which may cause trouble with an unwanted sustaining C4 note for the Devil Fish synthesiser and any slave devices running from its CV and Gate outputs When the TB 303 s Internal sequencer is in Pattern Play mode and one of these two combinations occur A The Internal Sequencer is Running the TB 303 s Run Stop LED labelled RUN BATTERY is On due to local Run Stop and Tempo DIN Sync In or MIDI Sync Receive and the Tap button is pressed for any reason such as any of the Devil Fish MIDI In system Front Panel operations including reducing the MIDI Receive Channel by 1 AND the Internal Sequencer is subsequently put into a Stop state or B The Internal Sequencer is not Running and the Tap button is pressed for any reason Two potentially annoying things will occur l The Internal S
24. cket and Internal Sequencer the MIDI In lead is unplugged from whatever is driving it and or from the Sync Socket Without special provisions the MIDI In system would keep driving the Run Stop high but would not be generating Clock pulses to the Sync Socket and so the Internal Sequencer Some MIDI slave devices such as the Cyclone Analogic TT 303 Bass Bot cope with this loss of Clock bytes by turning off their Run Stop state In order to halt the MIDI In system s drive of Run Stop if there are no incoming Clock bytes there is an Unplug Timer in the MIDI In firmware which turns off this drive after 1 5 seconds elapse with no incoming Clock bytes Note With a conventional MIDI lead plugged into the Sync Socket it is not possible to simultaneously receive MIDI Sync and receive DIN Sync However if a special cable is used including the Sync Cable with one of its three normally output DIN Sync connectors being driven with DIN Sync then it is possible that both the MIDI In system and the external source of DIN Sync will be driving the Sync Socket s Run Stop and Clock pins and therefore driving the Internal CPU The outcome of this would depend on many factors and I will not attempt to discuss this usage of the system For more details on such arrangements please see the section below Advanced use of the Sync MIDI In socket MIDI In whilst still using the internal Tempo Clock and Run Stop 24 6 Advanced use of the Sync MIDI
25. e except that the PIC microcontroller in the MIDI In system can take control of the DAC from the TB 303 s CPU When this happens if the TB 303 CPU drives the DAC as part of playing a note the DAC voltage will be controlled solely by the MIDI In system s microcontroller Plugging a lead into the CV In socket will mean that the VCO Filter Tracking pot and CV Out socket are driven by whatever signal is on that lead This means the output of the DAC and therefore the pitches received from MIDI IN will be ignored Note there is a potential problem with some Devil Fishes an occasional intermittent poor connection in the CV In socket s normally closed function means that the VCO pitch drifts remains static or is way out of tune The solution is to insert a plug a few times into the socket so the contacts get some movement This is discussed more fully in the Devil Fish User Manual in the section regarding reliability 13 Devil Fish Gate There are three signals which can turn on the Gate for the Synthesizer Gate the Gate Out socket and the Red Gate LED in the e of Devil 1 The TB 303 CPU s Gate signal 2 The Devil Fish s Gate In socket 3 In Devil Fish versions 2 1D 2003 11 11 and later a voltage above about 4 0 volts on the Slide In socket will also turn on the Gate These are ORed any one any two or all three of them being active will turn on Gate The MIDI In system can drive the Gate in a similar way
26. e or the internal Run Stop and Clock circuits drive the socket and therefore these two inputs to the CPU A common fault in TB 303s is that there are one or more broken solder joints at the Sync socket and its associated switch This can prevent the CPU receiving the Run Stop signal and or the Clock signal Without a Clock signal the CPU will not flash the front panel LED lights or respond to buttons being pressed Without the Run Stop signal the CPU will not play a pattern or track The Run Stop LED is also driven by the Sync socket if pin 1 is above about 0 5 volts the LED will be On but only if the power supply to the TB 303 s CPU is at the correct voltage If the power supply voltage is low such as due to running from flat batteries or using an inadequate external power supply then this LED will be dim or off 12 Normal note playing activity in the TB 303 when playing or writing patterns or tracks involves e The CPU latching a 6 bit number into the DAC e The CPU selecting whether or not the Slide circuit causes a slow slew in how the new DAC voltage drives the VCO and CV Out socket e The CPU turning the Accent signal on or off e The CPU driving the Gate signal to the Synthesizer and Gate Out socket The standard TB 303 has no inputs for CV to drive the VCO Gate Accent Slide or Filter frequency The Devil Fish Modifications add a number of inputs and new sources of control for CV Gate Accent Slide and Fi
27. e TB 303 0 Disabled 1 Mod wheel 2 to 19 this controller number 0 Disabled 1 Turn on Slide when a new note is started before the previous one ends 0 Disabled 1 Mod wheel 2 to 19 this controller number The value which Note On Velocity must equal or exceed in order that Accent will be turned on O 65 1 80 2 100 3 120 64 for V1 0 0 to V1 0 3 0 No reception of MIDI Sync 1 Receive MIDI Sync 10 4 Interaction between the MIDI In system and the TB 303 Devil Fish A full understanding of the various parameters and features requires a good understanding of the three elements of hardware the basic TB 303 the Devil Fish enhancements to it and how the MIDI In system interfaces to these The standard TB 303 The standard TB 303 can be divided into two sections Internal Sequencer and Synthesizer The Internal Sequencer section comprises The CPU chip a 4 bit NEC microcontroller Battery backed up memory three 1024 x 4 bit static RAM chips Push button switches rotary switches and LEDs The Sync section Run Stop button and flip flop Tempo pot and oscillator Sync socket The CPU chip contains firmware which makes it respond to all the above and so perform the functions of the Internal Sequencer This involves reading and writing data from and too the memory and controlling the Synthesizer section with the following signals A 6 bit DAC Digital to Analogue Con
28. e disabled by turning the machine on with the TAP button pressed and the BACK button not pressed Turning on and off the reception of MIDI Notes and Control Changes This is a single setting which is not stored in non volatile memory So whatever change you make will not be retained after the machine is turned off and on At power on the reception will be turned on Before following either of the procedures below make sure that the machine is not in the middle of the Altering the value of a parameter operation as described on page 7 If the machine is in this state press and hold both BACK and TAP buttons for a few seconds until there is either a series of double flashes a normal exit from editing a parameter or a continual series of flashes at about 6 Hz an exit before a parameter has been selected for editing Turn ON reception of MIDI notes and controllers Hold down the TAP button Press and release the BACK button within a second or so While both buttons are pressed the Blue LED will flash rapidly After the Back button is released the Blue LED will stay ON for 0 8 seconds and will then turn OFF Release the TAP button After reception is turned on the MIDI In system will not take control of the TB 303 s DAC until a Note On is received on the correct MIDI channel within the currently valid range of note numbers This control will still be maintained after no more MIDI events are received even if the MIDI lead is re
29. equencer will play and hold a note C above Middle C 2 0 volts C4 MIDI Note number 72 The pitch of this note is not affected by using the Pitch button and one of the keys to transpose the pattern This note will remain on until the Internal Sequencer starts playing again in this setting of the Mode Switch Pattern Play or in one of the other three Track Write Track Play or Pattern Write Simply changing the Mode Switch does not turn off the note 2 Any slave devices running from the Devil Fish s Gate output will receive a Gate On signal and so play this Pesky C4 note One workaround is to use Pattern Write Mode when changing the MIDI Receive channel or doing some other Front Panel operations However Pattern Write Mode does not allow two valuable features of having the Internal Sequencer playing in Pattern Play mode 1 The ability to transpose by pressing the Transpose button and one of the keys 2 The ability to change the Pattern being played including selecting multiple patterns with keys 1 2 2 3 3 4 1 2 3 2 3 4 5 6 6 7 7 8 5 6 7 and 6 7 8 The problem behaviour is built into the TB 303 s Internal Sequencer A second workaround is to use Pattern Play mode of the Internal Sequencer and accept that the Internal Sequencer s C4 note on the Devil Fish synthesizer via CV and Gate Out and via the Devil Fish s MIDI Out system will occur but use a quick Start and Stop action on the Devil Fish s Run Stop button
30. fect on any Note which is currently playing 23 Receive MIDI Sync parameter 7 The MIDI In reception of Sync is controlled according to the two possible values of Parameter 7 Parameter Receive Sync Unplug timer 7 value from MIDI In 0 Default 1 ON Enabled Changing this parameter s value from 1 to 0 resets any currently active Run Stop and Clock which the MIDI In system is driving to the Sync socket and TB 303 CPU The Turn Off reception of MIDI Notes and Control Changes command page 6 holding BACK and pressing and releasing TAP does not affect the reception of MIDI Sync So it is possible to receive MIDI Sync have the Internal Sequencer playing in time with a master device which is putting out Sync and possibly notes and Control Changes including the Filter Frequency Controller Parameter 3 and to alternate between e Enabling reception of MIDI Notes and Control Changes with these notes controlling the TB 303 s DAC which provides the Pitch voltage to the CV In socket where if nothing is plugged in it is routed to the Synthesizer and e Disabling this so the DAC is then controlled by the Internal Sequencer A potential problem with receiving MIDI Sync is if a Start byte has been received which causes the MIDI In system to turn on Run Stop drive to the Sync Socket and therefore the Internal Sequencer and if as is usual Clock bytes are being received and likewise used to create Clock pulses for the Sync So
31. he Sweep Resonance switch is in positions 1 or 2 e The AC coupled only rapid changes not the overall DC voltage output of the VCA which incorporates the Muffler via the Filter FM Pot e The CV from the internal sequencer or from the external CV input via the Filter Tracking Pot Linear e AC coupled signal from the Audio Filter FM input tip of old headphone socket Linear as well e DC coupled signal from the Filter CV Input Exponential about 1 volt octave The Filter Frequency will no longer be driven by the MIDI In system when any one of the following occurs 1 Note and Filter Frequency reception is turned off by holding BACK and pressing and releasing TAP See page 6 2 Parameter 0 Receive Channel is changed 3 Either of the Transpose parameters 1 and 2 are changed 4 The Filter Frequency Controller parameter 3 is changed Points 2 3 and 4 only cause a transitory disabling of the Filter Frequency drive As long as the MIDI In system is ready to receive Notes and Filter Frequency Control Changes that is point 1 has not been done or if it has been it is turned on again by holding TAP and pressing and releasing BACK see page 6 if the MIDI In system receives a Control Change message on the correct controller number parameter 3 and MIDI Channel parameter 0 then it will again turn on the Filter Frequency control The MIDI In system can receive Control Changes on controller numbers 1 to
32. he Sync socket without activating the switch pins 1 and 3 function as outputs for the Run Stop and Clock signals respectively This can be done by partially inserting the plug or by removing its shell or part of the shell so it doesn t press against the white rod inside the top of the Sync socket This is not a standard part of TB 303 functionality but it can be useful For further discussion see Section 6 below If a plug is inserted normally into the Sync socket this activates the two pole normally closed switch at the back of the socket which disconnects the local Run Stop and Clock circuits from the socket s pins 1 and 3 The idea is that the lead which has been plugged in will drive these pins The voltage levels for receiving Run Stop and Clock are not critical low should be 0 to maybe 1 volts and high should be between 3 and 15 volts So in normal operation whether an external Sync source is plugged into the TB 303 or whether nothing is plugged in and the local circuits drive pins 1 and 3 these pins have a valid Run Stop signal and a valid Clock signal The CPU sees these signals and uses them to drive most of its operations Without a regular Clock signal the CPU will not play any notes flash any LEDs or respond normally to front panel button activity The Sync system is a two signal input to the TB 303 s CPU The TB 303 s CPU does not drive the Sync socket In a TB 303 without this MIDI In system only an external cabl
33. imal 02 00000001 First data byte Controller 1 Mod Wheel 01111111 Second data byte Value 127 When this parameter is set to a value in the range 1 to 19 and a Control Change for this MIDI Controller number is received on the currently selected channel parameter 0 then the MIDI In system will begin to drive the Filter Frequency When this parameter is set to a value in the range to 19 and a Control Change for this MIDI Controller number is received on the currently selected channel parameter 0 then the MIDI In system will begin to drive the Filter Frequency The default setting is 1 which means the MIDI In system will receive Mod Wheel Control Change messages and use the values in these messages to control the Filter Frequency There is an approximately 5 octave range between controller values 0 and 127 A value of about 83 will not alter the filter frequency Values above this will increase the filter frequency and values below will decrease it This is equivalent to applying a 0 to 5 volt signal to the Filter CV socket where 3 3 volts has no effect on the filter frequency This MIDI control of Filter Frequency does not override the other sources of control it adds or subtracts from the sum of the signals generated by e The Cutoff Pot e The Main Envelope Generator via the Env Mod Pot e On accented notes the Main Envelope Generator via the Accent Sweep Circuit three modes controlled by the Sweep Speed switch if t
34. leteteenassislavscnncbcsceestauaedseenseedeietivecees 28 Robin Whittle 2004 2014 TB 303 is a trademark of the Roland Corporation 0 Quickstart and default behaviour The Devil Fish modified TB 303 can be fitted with a MIDI In system or a MIDI In and Out system Here are the most important things you need to know about the MIDI In system versions 1 0 4 and above It receives MIDI if you plug a MIDI lead into the Sync Socket It receives Note and Filter Frequency messages on Channel 1 This is the default the system can receive in any channel to 16 with this and other user controllable settings being stored in non volatile memory Middle C is the C on the left of the TB 303 keyboard in Pattern Write mode There are non volatile user settings for transposition Note On events with velocities 1 to 63 will be played without Accent and those with velocities 64 to 127 will be played with Accent ON The Devil Fish modified TB 303 is a monophonic instrument If two or more notes are active from MIDI In it will play the pitch of the most recent of these notes As this and other notes are turned off the pitch revert to the most recently turned on of the currently playing notes for up to a maximum of 10 notes being on at once If one or more MIDI In notes is still active when a new one is played the new note will be played with Slide ON Control Change 1 messages Mod Wheel control the Filter Frequency with an approximatel
35. lter CV The Devil Fish mods also add an Accent Out socket a 6 volt signal which can be used to drive other equipment such as one or more other Devil Fishes Here are descriptions of the four signals as they are handled in the Devil Fish without MIDI In and in the Devil Fish with MIDI In The MIDI In details are in bold blue text Devil Fish CV In The TB 303 CPU drives the 6 bit DAC which has in internal impedance of 100k ohms In the TB 303 this is connected directly to a the Slide circuit which can cause a slow slew when the voltage changes via a 0 22uF capacitor In the Devil Fish the DAC drives a normally closed terminal of the Devil Fish s CV In socket When nothing is plugged into this socket the DAC signal goes to the Slide circuit via an over voltage protection circuit 3 3k ohms and the new Slide pot 0 to 500k ohms When an external CV is plugged into this socket probably with a much lower impedance than 100k ohms meaning that it drives the socket in a more robust fashion than the relatively weak 100k ohm impedance of the DAC the voltage from the DAC is ignored and input voltage goes via the over voltage protection circuit and the Slide circuit slewing according to the value of the Slide pot 3 3k ohms the impedance of the input signal whenever the Slide signal is on The output of the Slide circuit goes to the VCO the Filter Tracking pot and the TB 303 s CV Out socket The MIDI In system is the same as the abov
36. moved from the Sync MIDI socket The MIDI In system will begin to drive the Filter Frequency only after a Control Change for this is received Slide and Gate Sustain can be driven by several types of MIDI In Control Change messages as well as after a Note On event has been received In order to return control of the DAC etc to the TB 303 s internal sequencer so the MIDI In system no longer drives Gate Slide Accent or Filter Frequency use the following procedure Turn OFF reception of MIDI notes and controllers Hold down the BACK button Press and release the TAP button within a second or so While both buttons are pressed the Blue LED will flash rapidly After the Tap button is released the Blue LED will stay ON for 0 2 seconds and will then turn OFF Release the BACK button The control of the reception of MIDI Sync is separate see Parameter 7 in the table and descriptions below pages 10 and 23 respectively Altering the value of a parameter There are 8 parameters numbered 0 to 7 which can have their values changed with the following procedure The details of these parameters are listed in the User Definable Parameters table on page 10 Please be aware that pressing the Tap button in Pattern Play mode can cause the Internal Sequencer to play a sustained C4 note as described in Section 7 The Pesky C4 Note in Pattern Play mode page 27 The MIDI In system continues to receive MIDI and play notes etc whilst parameter
37. no transposition Middle C Right C of TB 303 keyboard with no transposition Highest C of a pattern without transposition Right C of the TB 303 keyboard when Pattern Write Transpose UP is active Highest C of a pattern with 12 semitone transposition The pattern itself contains a C5 and in Pattern Play mode or Track mode the entire pattern has been transposed up 12 semitones 1 Semitones above normal range 98 D6 5 166 V 99 D 6 5 250 V 2 Semitones above normal range 3 Semitones above normal range 100 E6 5 333 V 4 Semitones above normal range A transpose value of for instance 3 can be achieved with Parameter 1 set to 1 and Parameter 2 set to 3 This would cause a MIDI Note number 57 A2 to play the C3 note on the TB 303 Devil Fish 20 Filter Frequency Controller parameter 3 When this parameter is set to 0 there will be no reception of Control Changes to drive the Filter Frequency A MIDI Control Change message consists of three bytes containing three numbers e The MIDI Channel number to 16 e The Controller number 0 to 127 e The value for this Control Change in the range 0 to 127 For instance if a keyboard is transmitting on channel 3 and its Mod Wheel is moved to the forward position the resulting MIDI Out message consists of three bytes 10110010 Status byte for Control Change on Channel 3 encoded as 2 in a range 0 to 15 for Channels 1 to 16 with binary 0010 dec
38. olding both buttons for about 3 seconds When you have pressed and held them for long enough the Blue LED will flash with a distinctive double flash pattern This is the signal to Release both buttons after which the Blue LED will turn OFF and the MIDI In system s Front Panel will be in normal operation mode 19 Transposition parameters 1 and 2 These two parameters affect MIDI In reception of incoming notes enabling received Note On and Off events to play a pitch in the Devil Fish which is different from that of the incoming MIDI Note The range of transposition is 24 to 24 semitones 2 octaves As with changing the MIDI Receive Channel changing these parameters ends any currently playing notes disengages the drive of the Filter Frequency and ends any drive of Slide Accent and Gate Without transposition the range of MIDI Notes which are received is MIDI MIDI DAC Note Note voltage number name 45 Al 0 750 V 46 A l 0 833 V 47 Bl 0 916 V 48 C2 1 000 V 60 C3 2 000 V 72 C4 3 000 V 84 C5 4 000 V 96 C6 5 000 V 97 CH6 5 083 V Relation to TB 303 sequencer Pale yellow means VCO tuning and CV Out voltage may be inaccurate 3 semitones below normal TB 303 range 2 semitones below normal TB 303 range 1 semitone below normal TB 303 range Lowest C on TB 303 sequencer Left C of the TB 303 keyboard when Pattern Write Transpose Down is active Left C of TB 303 keyboard with
39. ot connect to the outside pins The Evolution 225C has 5 volts and a 5 volt MIDI signal on the outside pins so that it can be powered by a special lead which plugs into a PC sound card s joystick connector Please use a special lead or an ordinary lead with the outside pins broken off between such a keyboard and the Devil Fish Another approach is to plug the keyboard into some other MIDI device and use the Thru of that device to drive the Devil Fish 2 The Front Panel The MIDI In and Out system uses a very minimal Front Panel the user interface by which user definable parameters can be changed and by which several other functions can be activated The BACK button and the TAP button are the two nput elements A Blue LED mounted so it shines through the e of the Devil Fish logo is the sole Display element The TB 303 s CPU sees the BACK and TAP buttons too so pressing them for the purposes of controlling the MIDI In system may also affect what the TB 303 s CPU does BACK and TAP have little or no effect when playing patterns in Pattern Play or Pattern Write modes except that when the internal sequencer is stopped in Pattern Play mode pressing TAP will cause it to play a high C note which lasts until the TAP button is pressed again or until some other action occurs When writing patterns BACK and TAP NEXT directly affect the writing operation so it is best not to try to control the MIDI In system while writing patterns N
40. ote This minimal Front Panel system will drive you bananas if you don t read the following section clearly Please pay close attention to these instructions regarding Pressing Holding and Releasing these two switches The order and timing of these actions is crucial Initialising the Parameters The Microcontroller at the heart of the MIDI In system uses non volatile memory which is completely independent of the memory of the TB 303 and which does not rely on any batteries If for some reason you want to initialise the values of the parameters to the defaults listed in the table on page 15 include receiving MIDI Notes and Controllers on Channel 1 and receiving MIDI Sync turn the machine on whilst holding both BACK and TAP The Blue LED will flash triple flash triple flash triple flash Release the BACK and TAP buttons during or after these flashes and the machine will be ready for ordinary operation Firmware version display To display the version of firmware programmed into the MIDI In and Out system s microcontroller turn the machine on whilst holding the BACK button but not the TAP button The Blue LED will continually cycle through a pattern of varying brightness Release the BACK button once the Blue LED turns on A long moderate brightness period is followed by three dim periods within which 0 1 or more bright flashes may be inserted The number of flashes indicates the software version Version 1 0 4 is indicated b
41. rst two types are only received if Reception of MIDI Notes and Control Changes is enabled page 6 e Bright 16 ms flash One or more Note On or Note Off messages have been received The LED will not flash if the message is for a different channel to the one currently being received or if it is for a MIDI note number which is outside the range the MIDI In system can play given the current Transposition Parameters and 2 settings If a Note On message is received for a MIDI note number which is already on then the second message will be ignored by the interface and will not generate a flash of the LED e Dim 160ms flash One or more Control Changes have been successfully received of three types These can only occur if Reception of MIDI Notes and Control Changes is enabled o Filter Frequency Control Change Parameter 3 o Sustain Slide Control Change Parameter 4 o Standard MIDI Control Change functions Controller 64 for Sustain Controller 65 Portamento for Slide Controller 120 and 123 All Notes Off Since one flash can be terminated and replaced by another and since one message can arrive within a millisecond of the previous one only Ims of the flash due to the first message will be visible and this is too short to perceive in the presence of a different type of flash which takes its place For instance a Control Change message followed by a Note On or Off message will cause a short bright flash while these two me
42. s are having their values altered the effects if any of the new value take place immediately The final step writes the altered value into non volatile memory If this final step is not done the changed setting will remain until the machine is turned off and will be replaced by the previously stored setting when the machine is turned on Entering Parameter Select mode Press and Hold both BACK and TAP buttons for as long as it takes for the Blue LED to stop flashing which will be about 4 seconds While the two switches are both pressed the Blue LED will flash repeatedly very quickly After about 4 seconds the flashing will stop and the Blue LED will turn ON continually It doesn t matter whether you press BACK or TAP first or how long after pressing the first switch you press the second Release both switches The Blue LED will turn OFF If you release either switch before the Blue LED turns on continually then the MIDI In system will not enter Parameter Select mode The system will resume normal operation once both switches have been released Selecting which parameter to alter If you want to alter the first parameter MIDI Receive Channel then there is nothing to do at this stage since this is the first parameter For other parameters further down the User Definable Parameters page 10 Press and Release the BACK button the number of times indicated in the table below The Blue LED will flash briefly each
43. socket connects the local Run Stop signal generated by the Run Stop switch and its associated flip flop to pin 1 and the Clock signal from the Tempo oscillator to pin 3 These are both 5 volt signals O volts on the Run Stop pin means that the TB 303 s Internal 11 Sequencer will not play a pattern or track but is ready to play or write a pattern or track according to the MODE switch 5 volts or more up to 15 volts on the Run Stop pin tells the TB 303 s Internal Sequencer to Run play a pattern or the patterns in a track according to the pulses which arrive on the Clock pin The positive rising edge of these pulses again typically 5 volts but perhaps as high as 15 volts on the Clock pin tells the Internal Sequencer that this is the start of a 1 24th of a quarter note The Clock circuit is normally a free running square wave oscillator but it is reset and made to restart with a slight delay every time the Run Stop button is pressed so as to turn Run Stop on This is to ensure that the Run Stop signal goes high at the start of playing a pattern or pattern of a track when the Clock signal is low and that there be a defined time delay before the next rising edge of the Clock signal This delay is musically unimportant but is vital to allow the TB 303 s CPU to recognise this first Clock cycle rather than miss it while the CPU is responding to the rising edge of the Run Stop signal If a plug is inserted into t
44. ssages received in the reverse order will cause a longer dim flash MIDI Receive Channel parameter 0 Changing this parameter turns off a number of things which may be on 1 Any note being played This also clears the 10 deep stack of notes which is used to convert polyphonic notes into monophonic notes 2 The MIDI In system s control of the control voltage DAC 3 The MIDI In system s control of Filter Frequency 4 The MIDI In s drive of Slide Accent and Gate Notes and Control Changes are immediately received on the new channel which may lead to notes being played and other effects such as Slide or Accent The flashing of the Blue LED for Notes and Control Change commands is turned off during the parameter change process so if you are fishing for the right MIDI channel it is probably best to do this by listening for notes or looking at the Red Gate LED since it takes quite a few seconds to exit from the parameter change process in order to see the Blue LED activity which indicates successful MIDI reception As with all the parameters be sure to exit the change process by holding down both BACK and TAP buttons in order to save the new setting to non volatile memory and to return the system to ordinary operation Here is an example of changing the MIDI Channel to 5 assuming it was previously set at the default of 1 18 a enter Parameter Select mode Press and Hold both BACK and TAP buttons for as long as it
45. te In versions 1 0 4 and later I removed this feature For V1 0 0 V1 0 1 and V1 0 2 and for V 1 0 4 if the Run Stop LED remains on after the MIDI In lead has been removed the easiest way to restore normal operation is to turn the machine off and on again Machines I work on to install 1 0 4 or later versions will have a hardware change which resets the Internal Sequencer s Accent flip flop at power on 28 9 Document history 2004 12 22 Added Firmware version history section covering up to Version 1 0 1 2004 12 24 Updated material on Slide MIDI In overrides both TB 303 CPU s Slide and the Devil Fish Slide input not just the TB 303 CPU s Added material on how this override begins and ends 2005 02 10 Minor improvements and added details of the new MIDI and three output Sync lead 2005 02 16 Updated for Version 1 0 2 Added note about Evolution keyboards having 5 volts and a MIDI signal on the outside pins 2007 11 27 Added link to Sync Lead page 2008 01 01 Added documentation of version 1 0 3 firmware 2010 01 02 Converted to PDF format 2013 03 02 Added notes about the behaviour of the Blue LED when pressing buttons Slightly rewrote some button pressing instructions 2013 07 06 Corrected instructions on how to display the firmware version number 2013 08 10 Forked the manual into three documents for the V1 0 0 to 1 0 3 MIDI In systems for the 1 0 4 MIDI In system and for the 2 1 0 MIDI In and Out system 2013 08
46. time the BACK button is released Once you have done this the appropriate number of times Press and Release the TAP button The Blue LED will flash once If during this procedure you decide not to change a parameter press and hold both BACK and TAP for about 3 seconds During this time the LED will not light but at the end of the time it will flash with a distinctive sequence of double flashes These double flashes indicate that your command to exit has been accepted Release the buttons and the MIDI In system will resume normal operation Altering the value of a parameter The parameter you selected is now ready to be incremented made one higher than it currently is with the BACK button or decremented made one lower with the TAP button There is no absolute display of its current value but you can find the value by stepping it down with BACK until it reaches is minimum which is visible by a longer flash of the Blue LED Similarly even if you don t know the current value you can step down to the minimum or up to the maximum and then step backwards to the value you require Increment the parameter Press and Release the BACK button Decrement the parameter Press and Release the TAP button The Blue LED will flash briefly once for either of the above actions except when the parameter has reached its minimum or maximum value Each parameter has a minimum and maximum value If you Decrement when it is at its minimum
47. ver this will only occur after at least one Note On has been received so that the MIDI In system has taken control of the TB 303 s DAC The Blue LED will show a longer dim flash for each reception of this controller but only when a note is played will the Gate and Slide be turned on The intention is that a sequencer or more likely a live player will manipulate a controller number such as 6 via a Data Entry Slider of a keyboard to select Slide and or Sustain The effect of the controller values are Controller value Sustain Slide Gate 0 31 32 63 On 64 95 On 96 127 On On Please see the Gate and Slide sections of Section 4 above pages 14 and 15 for details of how these signals are ORed with other signals to create the final Gate and Slide signal to the synthesiser Accent Velocity Threshold parameter 6 This parameter selects which of four thresholds will be used to decide whether a new Note On event will activate the Accent signal to the synthesiser For instance if this parameter is set to 0 default then any Note On with a velocity of 65 or above will activate the Accent signal Instruments which output a Note On event without variable velocity typically use 64 for each note s velocity Parameter Threshold equal to or above which Note 6 value On Velocity will activate Accent 0 65 For MIDI In V1 0 0 to V1 0 3 this was 64 1 80 2 100 3 120 Kor V1 0 0 to V1 0 3 this was 64 Changing this value has no ef
48. verter which provides a voltage between 1 0 and 5 0 volts in 1 12 volt steps This voltage is made available at the CV Out socket Its range is 1 to 64 steps of 1 12 volt each but below 1 volt and above 5 volts it is not necessarily accurate and the VCO tracking of these voltages is less accurate than in the 1 0 to 5 0 volt range A Gate signal which is high when a note is ON This is available at the Gate Out socket as an approximately 6 volt signal An internal Slide signal which controls the slewing of the CV to the Synthesizer s VCO and the CV Out socket so that it takes a fraction of a second to slew from the voltage of the previous note to the voltage of the new note as produced by the 6 bit DAC An internal Accent signal which alters the way the Synthesizer works See the Devil Fish User Manual for more information on Slide and Accent The TB 303 s Sync section consists of two front panel circuits a Tempo Clock oscillator and a Run Stop switch flip flop and LED and a special 5 pin DIN socket This socket uses the middle pin 2 for ground as does MIDI and the two outside pins 1 and 3 for the Run Stop and Clock signals respectively Pin 4 is also an input for the TAP function and Pin 5 for some undocumented function These are not normally used in any Sync arrangement and these functions are removed when the MIDI In system is installed Normally with nothing plugged into the Sync socket a two part switch in the
49. y 5 octave range This control adds to rather than overrides all the other internal signals and the Cutoff pot which also affect the Filter Frequency The rest of the manual describes other functions such as controlling Slide and Accent with MIDI Control Changes changing the receive channel setting a transposition value etc The machine receives MIDI Sync messages Start Continue Stop and Timing Clock If your master sequencer or drum machine outputs these most will do so by default then when you drive the Devil Fish from the master device s MIDI Out the TB 303 s Internal sequencer will start run in time and stop in sync with the master device When the master device is not playing a song it will typically output MIDI Timing Clock messages at whatever tempo it is set to run at These will enable the TB 303 s Internal Sequencer to flash its LEDs in whatever mode it is in Pattern or Track Write or Play 1 Overall description This MIDI In system is an additional modification I can install in a Devil Fish modified TB 303 It is not available as kit for someone else to install I usually install it as part of the Devil Fish mods where I have provision for it on the Version 4 0 and later printed circuits It is also possible for me to install this system on Version 2 x or 3 x Devil Fish modified TB 303s by replacing the two original Devil Fish circuit boards with two new ones This is a MIDI In system with no Out or
50. y one flash in the first dim period no flashes in the second dim period and four flashes in the third In this mode the microcontroller is not receiving MIDI or driving the TB 303 hardware To restore normal operation turn the machine off and on again MIDI Notes and Control Changes are received by default at power on In V1 0 0 to V1 0 3 I intended that the state of whether the Devil Fish receives MIDI Notes and Control Changes would be retained in non volatile memory Due to a bug it wasn t reception would always be on at power up No one complained about this and I decided to retain this behaviour in V1 0 4 In the MIDI In and Out system I have made it a setting which is stored in non volatile memory Blue LED MIDI activity display and how to disable it The Blue LED which shines through the Red Gate LED in the e of the Devil Fish logo has five functions 1 Acknowledging the Initialise all Parameters command as described above 2 Displaying the firmware version as described above 3 Indicating the status of Front Panel operations the pressing and releasing of the BACK and TAP buttons 4 Indicating successfully received MIDI In messages with brief flashes as described in the section below The Blue LED This function is normally on except for when Front Panel operation is in progress The Blue LED circuit may cause very slight interference with the audio output Its operation for function 5 above can b
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