Coda 1 User's Manual
Contents
1. It is important to remember the correct left or right channel orientation The function and channel markings on the rear panel correspond to the front panel controls and their signal paths 1 The GROUND post should be attached to the ground wire from a turntable 2 The PHONO LINE inputs should be attached to either the outputs of a turntable or if using the bypass option may be treated as another line level 3 The CD TUNER and VIDEO input connections are allline level inputs requiring only the insertion of the RCA plugs 4 The RECORD ONE and TWO inputs should be attached to the OUTPUTS of the corresponding recording device alternately they may be used as additional line inputs 5 The RECORD ONE and TWO outputs should be attached to the INPUTS of the corresponding recording device 6 The OUTPUTS unbalanced should be attached to the amplifier inputs either directly or through a crossover or processor as appropriate to the application 7 The BALANCED OUTPUTS should be attached to the balanced inputs of the amplifier either directly or through a crossover or processor as appropriate to the application 8 The AC LINE INPUT should be attached to the power cable provided with the pre amplifier After making the appropriate connections and rotating the level control fully counter clockwise insert the three prong safety plug into an appropriate AC power source Once properly connected the LED on the front panel will light A2. an open minded fashion with no compromise musical perfection as the goal The resulting refinement of the product escapes simple explanation With this in mind we present here a few design highlights and concepts All voltage gain is derived from FETs While careful design can yield good results from any device type FETs consistently seem to have the edge in voltage gain and interface applications This is borne out by superior sonic qualities observed in subjective testing FETs are inherently transconductance devices meaning that an input voltage controls an output current In other words it senses the audio signal without drawing current from the source to provide an output This eliminates complex interactions with the source allowing maximum performance from each system element and greatly reducing the chance of cable characteristics altering the sound The absence of input current in FETs also allows high bias currents for linearity andspeed without sacrificing DC parameters While excellent capacitors for coupling use exist there can be no doubt that a signal path free of coupling caps yields the best possible signal integrity The DC stability of the circuit eliminates the need for any questionable DC servo circuits or coupling capacitors We make no AC compromises for DC performance however Our key design choices provide not only inherent DC stability but also optimized AC performance throughout the audio region and well beyond The
3. that is required If a cleaner is necessary any dilute commercial ammonia based product will be appropriate NEVER use any abrasive rags cleaners or chemical solvents on the preamp When removing the cover to set the loading switches or otherwise handling the unit take care not to mar the aluminum Aluminum is a medium hardness metal and can be scratched by the harder tool steels Avoid exposing the unit to direct sunlight and keep it away from sources of intense heat If you wish to rack mount your FET PREAMPLIFIER 01 it is advised to place nylon washers under the heads of the mounting screws to avoid scratching the anodized finish Do notthrow away the carton or associated packing material They are idealif youneed to pack the unit for moving and in the unlikely event that servicing is needed they will be necessary for safe shipment Be sure to provide adequate insurance when shipping WARRANTY 13 Warranty Any failure of the FET PREAMPLIFIER 01 to operate or to meet specifications applicable at time of manufacture due to a manufacturing defect or component failure will be corrected by Coda Technologies Inc without charge for parts or labor for a period of ten years from date of original purchase Coda Technologies Inc will provide for surface transportation to and from the factory from an authorized Coda Technologies Inc dealer for a period of one year from date of purchase Il Procedure If the FET PREAMPLIFIER 01 s
4. the following diagram Note These switches may also be used for selecting absolute phase USA EUROPEAN E gt i M a Ri dumm E il XLR BOARD XLR BOARD um BALANCED OUTPUT un m OUTPUT fo NW IN ft N Z A O o o S 3 3 227 3 OD NW y p m A A y NS 4 Position the FET PREAMPLIFIER 01 in the space which you have chosen leaving enough space to connect the ancillary components of your audio system and the AC power cord for the preamplifier Although the FET PREAMPLIFIER 01 has the ability to reject external fields that produce system noise it is recommended that the unit not be placed near any sources of strong electromagnetic energy 5 Before installation make sure all ofthe power switches of any associated components are switched off If any of your other audio components do not have power switches make sure they are unplugged from their AC power source in order that it may be used worldwide Contact your dealer to arrange altering the operating voltage Note The Operating Voltage of the FET PREAMPLIFIER 01 is convertible DETAILED INSTALLATION 6 Il Source Output and Power Connections The input and output connectors are clearly marked on the rear lip of the top cover
5. CAL DATA 11 HIGH LEVEL Frequency Response Distortion Gain Maximum Output Noise Input Impedance Output Impedance Crosstalk PHONO STAGE Frequency Response Distortion Gain Maximum Output Noise Input Impedance Crosstalk BUFFER Frequency Response Distortion Gain Maximum Output Noise Output Impedance DIMENSIONS Height Width Depth Weight DC to 3dB 200kHz lt 01 percent from 10Hz to 40kHz 6 Volts peak into 600 Ohms or higher shunted by 1000pF or less 14dB unbalanced 20dB balanced 12 Volts peak gt 100cB referenced to 1 Volt output 20k Ohms 15 Ohms non reactive unbalanced 30 Ohms non reactive balanced 700B 20kHz 2dB of RIAA with an additional subsonic rolloff at 14Hz lt 01 percent from 10Hz to 40kHz 3 Volts peak output 37dB 1kHz Low 570B O 1kHz High 12 Volts peak gt 85dB referenced to 1 Volt output 22 Ohms to 47k Ohms 50pF to 1050pF see Set Up 700B O 20kHz DC to 1 MHz 01 percent from 10Hz to 40kHz 3 Volts peak into 20k Ohms O dB Unity Gain 12 Volts peak gt 100dB referenced to 1 Volt 1k Ohm non reactive 1 75 Faceplate 2 35 Overall 19 0 Faceplate 17 0 Chassis 9 75 Overall 15 Ibs Shipping CARE and HANDLING 12 Theinterior of the unit requires no special care due to the use of sealed controls and gold plating on contacts If ift becomes necessary to clean the exterior a simple dusting may be all
6. D INSTALLATION 4 I Set up and Installation WARNING NEVER OPERATE THIS UNIT WITH THE TOP COVER REMOVED NEVER MAKE ANY 1 Ifthe phono stage has been incorporated in the preamplifier it will be necessary to set the gain as well as the loading for each channel prior to installing the unit With the unit unplugged remove the coverusing the supplied Allen key The default value forthe gain is Low such as would be used with a high output Moving Coil or a Moving Magnet cartridge The High setting will provide an additional 200B of gain if necessary for lower output cartridges LOW HIGH LOW PHONO STAGE HIGH 2 In order to set the input loading it will be necessary to toggle the DIP switches which are located on the main board ofthe preamplifier Each one of these switches connects aresistor or capacitor in parallel with the input and so adjusts the load value The default values are 47k Ohms and 50pF Refer to the diagram below which is repeated inside The unit to determine the values which need to be switched in for your cartridge Replace the cover after setting the switches 1000 PF 22 Q 1000 PF 200 PF 47 Q 200 PF 100 PF 100 Q 100 PF 50 PF 34 r 1000 50 PF DETAILED INSTALLATION 5 3 The balanced outputs are equipped with switchable phasing due to differences in the USA EUROPEAN standards The default setting is EUROPEAN but may be switched according to
7. FET PREAMPLIFIER 01 OPERATION MANUAL H NO LO G I E S INC SAFETY PRECAUTIONS INTRODUCTION 2 INSTALLATION CONNECTIONS 3 DETAILED INSTALLATION 4 DESIGN PHILOSOPHY 8 TECHNICAL DATA 11 CARE and HANDLING 12 WARRANTY 13 WARRANTY REGISTRATION 14 ADDRESS 15 SAFETY PRECAUTIONS CAUTION A WARNING A CAUTION TO PREVENT ELECTRIC SHOCK DO NOT REMOVE COVER NO USER SERVICEABLE PARTS INSIDE REFER SERVICING TO QUALIFIED SERVICE PERSONNEL THIS SYMBOL IS TO ALERT YOU OF THE PRESENCE OF UNINSULATED DANGER OUS VOLTAGE WITHIN THE UNIT S ENCLOSURE THAT MAY BE OF SUFFI CIENT MAGNITUDE TO CONSTITUTE A RISK OF ELECTRIC SHOCK THIS SYMBOL IS INTENDED TO ALERT YOU OF THE PRESENCE OF IMPORTANT OPERATING AND MAINTENANCE INSTRUCTIONS IN THE LITERATURE ACCOMPANYING THE UNIT WARNING TO PREVENT FIRE OR SHOCK HAZARD DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE TO AVOID ELECTRICAL SHOCK DO NOT OPEN THE UNIT REFER SERVICING TO QUALIFIED PERSONNEL CAUTION Never install or remove the power cord from the chassis unless it has been disconnected from the AC power source first Never pull on the power cord when removing it from an AC power source Grasp it by the plug Do not leave the power cord connected to an AC power source unless it is connected to the unit It is recommend that during extended periods of nonuse that the units power cord be unpluged from its AC power source Route the AC power cord so that it will
8. hould require service under warranty take it with proof of purchase date with its carton and packing material to a CodaTechnologies Inc dealer The dealer will arrange for service Direct shipments to the factory will be accepted at the discretion of the company Coda Technologies Inc products purchased outside of the U S will be covered by those warranty conditions extended by the importing distributor which may differ in some respects from those given above Warranty service if required is the responsibility of the importing distributor If a Coda Technologies Inc product is removed from the country of original purchase Coda Technologies Inc distributors or dealers are not obligated by the conditions of this warranty and repairs will be affected at their discretion Ill Exclusion of Coverage At the sole opinion of Coda Technologies Inc the following situations are specifically excluded from coverage 1 Any FET PREAMPLIFIER 01 not operated in accordance with the instructions contained in this manual or otherwise subjected to abuse tampering modification accidental damage or serial number defacement 2 Damage to other property caused by any defects in this product damages based upon inconvenience loss of use ofthe product loss of time commercial loss or any other damage whether incidental consequential or otherwise 3 Itis Coda Technologies Inc policy to extend coverage when reasonable doubt exist however freigh
9. iodes The resulting voltage is heavily filtered and delivered to each stage through independent class A followers which completely decouples the stages The resulting non reactive low impedance over an extremely wide bandwidth yields a perfect power source for the individual circuits The simplicity and absolute stability of the supplies removes the chance of unpredictable interactions which may occur with the more elaborate high feedback circuity often used Most companies in the upper end of the audio industry use either sheet metal or formed aluminum By contrast the FET PREAMPLIFIER O1 has all structural parts made of machined extruded aluminum The advantage of this over an all stamped chassis is that the machined metal can be worked more precisely allowing us to work on tighter tolerances and use PC mounted parts more easily Moreover such a design allows easier servicing either for repair or for future upgrading From the standpoint of appearance a machined surface can be contoured in a far more precise manner giving the final product a more seamless appearance DESIGN PHILOSOPHY 10 II Parts Quality 1 Finishes All exterior and interior metal parts are anodized While paint may be more impactresistant the anodized surface is more resistantto solvents and prevents corrosion Moreover the anodized parts appearance can be enhanced by either graining or bead blasting the surface 2 Circuit Boards Circuit boards are fiberglass ep
10. ive plastic potentiometer used to adjust the voltage level at the outputs and balanced outputs Clockwise rotation of course increases output 1 2 3 4 5 INPUT SELECTOR RECORD SELECTOR MODE BALANCE OUTPUT LEVEL COMPACTOSC RR o P THER Mono D A voro moomo 7 4 S N FETPREAPLAER 01 RECORD WO Select a source with the INPUT SELECTOR switch and advance the OUTPUT LEVEL control to the level you wish Keep in mind that your input sources will vary in level which can when switching from one input to another abruptly yield uncomfortable sound pressure Note If a power interruption occursto the system reduce the OUTPUT LEVEL control gain The resumption of power will cause no noise pulses in the FET PREAMPLIFIER 01 However some sources may produce high output voltages on turn on which may cause damage to an amplifier or speakers DESIGN PHILOSOPHY 8 I Design Philosophy and Approach The circuitry utilized in your FET PREAMPLIFIER 01 is the result of an advanced and complete design process combining innovation and proven fundamentals This process avoids both the limitations of total adherence to convention and the flaws resulting from inappropriate application of clever circuit gimmicks Our approach demands painstaking consideration of every facet of each design choice regardless of how small Analytical as well as subjective techniques are all applied in
11. not be damaged or walked on INTRODUCTION This preamplifier is a precision device designed in an effort to provide the listener with unmatched sound quality design and construction In orderto operate your preamplifier properly and to realize all of the capabilities of the FET PREAMPLIFIER 01 we recommend that you read this entire manual carefully INSTALLATION CONNECTIONS 3 The first section of the installation instructions for the FET PREAMPLIFIER O1 is a diagram of the basic configuration required to bring the preamplifierinto an operating mode These brief steps will allow you to begin operating your system Make sure during installation that the level control is turned fully counter clockwise all other components are off and AC power connections are interrupted to the preamplifier While the diagram may be self explanatory we strongly recommend that you read the detailed instructions following this introductory section LL pe x emm uu Dae ane um sea eM uu O ua ur e umm e POWER AMP PHONO LINE POWER AMP COMPACT DISC TUNER INPUT OUTPUT INPUT OUTPUT RECORDER TWO RECORDER ONE pe DETAILE
12. nputs on many power amplifiers The most commonly acknowledged advantage of this is rejection of stray noise pickup but improvements in distortion and bandwidth may occur also While many manufacturers intentionally omit recording buffers on the grounds of signal path simplification the potential advantages of their use were worth an investigation The resulting experimentation ended with the development of a circuit of such simplicity and performance that its transparency was guaranteed The circuit is simply a direct coupled class A FET follower Because of the FETs inherent characteristics the buffer provides total isolation of the recording system from the main signal In addition it provides a relatively high purely resistive load to the source and arelatively low purely resistive drive to the recording system This assures consistent stability and freedom from interactions including cable effects The requirements of a power supply for flawless audio reproduction are straightforward but important The supplies in the FET PREAMPLIFIER O1 take a very direct approach to high performance First a top quality shielded toroid transformer with plenty of reserve current capability is used The shielding eliminates strong fields which could induce hum into sensitive circuitry About 20 000 uF of capacitance with very low ESR andinductance provides good passive filtering A reference voltage is developed by delivering a constant current to zener d
13. oxy with gold plating over a tin nickel barrier This gold layer will not corrode while the barrier plate prevents the gold from migrating to the lower copper layer and detracting from its appearance 3 Resistors All are high reliability metal film 1 resistors 4 Capacitors All capacitors have been eliminated where possible on the basis that no cap is better than the best cap Where they are used in the active part of the circuitry they are high quality film caps The only electrolytics used are in the power supply where large numbers provide enormous filtering capacitance for the supply 5 Semiconductors There are no integrated circuits IC to be found inthis product Very high quality dual FETs are the only source of voltage gain and were selected for their superb noise performance and precision matching The remaining semiconductors are also of very high quality each possessing parameters ideally suited for the specific application 6 Potentiometers The volume controls are conductive plastic These potstrack with little error and are totally neutral 7 Connectors Coda employs a standard RCA configuration with a gold plated case The balanced output connectors are Neutriks from Switzerland These are black chrome finished with gold contacts 8 Wire All signal wire has been eliminated whenever possible Where wire is used Coda employs silver plated copper 141 strand 18 gauge wire with a silicone insulation TECHNI
14. se choices include the use of top quality dual FETS in differential configurations for all voltage gain Because the signal in these stages is handled in a balanced manner rejection of unwanted noise and modulation from external sources is extremely high This rejection extends even to noise which may originate within the circuit from support circuity such as current sources Stray RF signals are also rejected well Inthe phono stage where the necessary equalization requires the use of capacitors we use only high grade film types These and other equalization components were carefully chosen to maintain response to within 2dB of RIAA standard An additional subsonic rolloff at 14 Hz serves to reduce IM Distortion Noise is kept low by paralleling input devices careful selection of circuit impedances and pre screening of devices The class A complimentary followers used to drive the preamp output are of such speed linearity and low output impedance that no feedback correctionis required or used The advantage of this is that the circuit s perfect stability and transient response are preserved into a wide range of difficult and unpredictable loads Variation in sound which could occur through interactions with interconnect cables and other system elements are thus avoided A simple very high performance inverter provides a fully balanced output on the preamplifier which allows the user to take advantage of the DESIGN PHILOSOPHY 9 balanced i
15. t charges will be billed for any units returned under warranty and found by the company to be operating according to specification This warranty gives you specific legal rights and you may also have other rights which vary from state to state Coda Technologies Inc continually researches new techniques designs and construction methods and so reserves the right to introduce refinements into current productlines without notice or obligation The company may offer product modifications to make these refinements available to earlier production units WARRANTY REGISTRATION Fill in and retain this copy of the warranty registration sheet for your records MODEL DESIGNATION SERIAL NUMBER DATE OF PURCHASE PLACE OF PURCHASE Dealer Adaress City State Zip Phone PURCHASER Name Adaress City State Zip Phone NOTES WARRANTY REGISTRATION 14 5 Please fillin and send this copy of the warranty registration sheet to Coda Technologies Inc MODEL DESIGNATION SERIAL NUMBER DATE OF PURCHASE PLACE OF PURCHASE Dealer Adaress City State Zip Phone PURCHASER Name Adaress City State Zip Phone NOTES ADDRESS Coda Technologies Inc 994 Horn Road Suite A Sacramento CA 95827 USA Phone 916 363 4653 Fax 916 363 4627 15
16. t this point you may switch on your chosen ancillary components including the power amplifier 8 7 6 5 4 5 4 3 2 i bob EE Das emm ul CRI CEE AE DETAILED INSTALLATION 7 Ill Front Panel Control Functions 1 The INPUT SELECTOR control selects the source which will be presented to the unbalanced OUTPUTS and BALANCED OUTPUTS 2 The RECORD SELECTOR control selects the source which will be presented to both of the record outputs Because of the independent controls one source may be monitored while a second different source is being recorded Caution Do not attempt to activate the record mode of a recording device when it is selected as a recording source Thisis an illogical state and may cause oscillation of the recording device If the monitor control is set for this device the oscillation may produce damaging levels at the unbalanced outputs and balanced outputs 3 The MODE control allows selection of stereo and reversed stereo as well as mono summed output The BALANCE control works by attenuating the right channel when being rotated from the detent in the counterclockwise direction and conversely the left channel for clockwise rotation The element is conductive plastic Adjustment is continuously adjustable allowing for infinitesimal adjustments to match channel gain which is impossible with stepped controls 5 The OUTPUT LEVEL control is a precision tracking audio taper conduct
Download Pdf Manuals
Related Search