User Manual “The Grail” Phonograph Preamplifier
Contents
1. User Manual The Grail Phonograph Preamplifier The Grail D Contents INTRODUCTION SAFETY PRECAUTIONS INSTALLATION AND USE Overview of the device Connection of the preamplifier Choosing the right input Impedance matching Level matching Some hints PROBLEM SOLVING TECHNICAL SPECIFICATIONS WARRANTY van den Hu Phonograph Preamplifier The Grail INTRODUCTION Congratulations with your purchase of the van den Hul The Grail With this product you are the owner of one of the most innovative and advanced phonograph preamplifier s available at the moment The Grail is a really dulcet phonograph preamplifier specifically designed bearing ultimate performance and reliability in mind Featurelist a specific designed Phonograph preamplifier section unique in the world Phonograph RIAA equalization with coils only no sound impairing capacitors in filters special printed circuit board material with gold conducting paths the printed circuit board has a special seating to evade microphonics special equipment foot made of selected wood avoids mechanical energy storage low noise moving coil input stage no annoying noise even with low output cartridges automatic adapting input stage for moving coil cartridges no matching resistors needed possibility to compensate phonograph cartridge sensivity level adjustment cut out of coupling capacitors in the signal path as far as possible str2. 10 PROBLEM SOLVING In case of a malfunction take a look at some things 1 The power switch of The Grail is in on position Is the proper mains voltage available Are all other amplifiers switched on control amplifier power amplifier Is the corresponding input channel of the control amplifier chosen Volume knob is not at the left latch 2 Is the wiring of all components in the audio chain correct No fallen off connectors 3 Is the fuse in the transformer box of The Grail blown up You can open the fuse holder item No 2 of the picture of the rear side of the external transformer box and take out the fuse If it is blown replace it with a fuse of the same kind and value Fuse type 800mA slow acting size 5x20mm If this fuse blows up again please unplug the mains plug and bring the preamplifier to an authorized service point for repair 4 Are the two fuses in the preamplifier The Grail blown up You can open the preamplifier housing by removing the four cross recess screws of it s top plate Remove the top plate The fuses are located in the upper right corner near the power supply connector item No 7 of the picture of the rear side of the preamplifier Take out the fuses and look if they are blown If so replace them with fuses of the same kind and value Fuse type 2pcs 1 25A slow acting size 5x20mm If these fuses blow up again please unplug the mains plug and bring the preamplifier to
3. The Grail preamplifier Connection of the preamplifier Some words in front The Grail is a high quality preamplifier that delivers you the finest possible sound But it can do this only if you use the right cables using cheap bad sounding cables will seriously degrade the sonic benefits you can get from The Grail Save your investment use the best cables you can afford e g cables from the van den Hul cable line They will deliver you the best possible sound available at this moment Power supply Be sure the main switch of the transformer box is in position off symbol o Connect the transformer mains power connector with the power cable to your mains wall plug Take care two versions are available one for 115Volts and one for 230Volts Be sure it matches to your mains voltage Now connect the round shaped low voltage connector sitting at the end of the gray cable coming from the transformer box to the preamplifier s rear side item No 7 of the picture of the rear side of the preamplifier Audio signal connections Connect your high level control preamplifier with a pair of high quality cables with RCA phonoplug Cinch connectors with the phonograph preamplifier The Grail The connectors at the rear side of The Grail are named Out connect them to a free high level input of your control amplifier e g Aux or Line Connect the cables coming from your turntable either with the
4. preamplifier please unplug the mains plug immediately and bring the preamplifier to an authorized service point for inspection Do not allow children to play with the preamplifier and do not let them use it without your supervision Keep the preamplifier out of the reach of pets Keep away the preamplifier from hot surfaces and from open fire Don t use it on top of another audio system parts that emits heat van den Hu Phonograph Preamplifier The Grail 4 INSTALLATION AND USE Overview of the device The Grail Front side 1 Power on indicator red Led the Netherland an dn Hd ce 20094 The Netherlands Rear side 1 Toggle switch MM MC input selection 2 Ground connector for turntable ground signal tonearm motor base etc 3 MC phonograph cartridge input low medium output level MC system 4 MM phonograph cartridge input also for high level output MC systems 5 Connector for input load of MM input for load resistor load capacitor 6 Preamplifier output connectors left and right channel 7 Power supply connector to connect with external transformer use no other transformer then the dedicated one for The Grail van den Hul Phonograph Preamplifier The Grail Transformer box 1 Power switch for mains power 2 Fuse holder Fuse 800mA slow acting for 230V version 3 Mains power connector for standardized IEC power connector 4 Power supply connector connect to
5. cartridge is done van den Hu Phonograph Preamplifier The Grail 8 Level matching To compensate the various level differences between all your audio sources The Grail gives you the possibility to change the amplification factor This amplification factor variation is also meaningful if you use a quite super low output voltage MC cartridge or your high output voltage MC system is just at the low side of it s kind and you would like to use it at the MM input of The Grail Also conceivable your complete audio chain has a quite low amplification factor and you use speakers with low sensivity In all this cases it is meaningful to adjust the amplification factor of your phonograph preamplifier With The Grail this is easy done Simply remove the four cross recess screws of it s top plate Remove the top plate and take a look inside of the preamplifier you will find 4 small switches in form of a single DIP switch DIP Dual Inline Plug Please take a look at the picture below it shows the mentioned DIP switch color of the switch may be red or blue in your amplifier o gt r m L Switch No 1 and No 2 belong to the right channel and switch No 3 and No 4 belong to the left channel Default position delivery condition is all switches in position off That means the basic amplification factor is for MC input 56dB and for MM input 33dB Simply choose the desired amplifi
6. system but this time you use no resistors but instead high quality capacitors like Polystyrene type capacitors and solder them into the male Cinch connectors Reasonable capacitor values may vary from 47pF up to 330pF pF means PicoFarad Hint Keep in mind that your cable has an inherently capacity and the input of The Grail has also a 50pF input capacitance So you only have to add the missing part of the recommended total capacitance given by the cartridge manufacturer In practice Let s say the recommend capacitance for your MM cartridge is 470pF Your cable from turntable to The Grail preamplifier has a 90pF each meter and you just have one meter of this cable you get a total capacitance of a cable capacitance 90pF b The Grails input capacitance at the MM input 50pF Result 100pF 50pF 140pF c Missing value 470pF 140pF 330pF Commercially available is a Polystyrene capacitor of 330pF For example take this one and solder it into a suitable Cinch connector Normally it is a good advise to take the lower end of the recommended capacitance range also commercially available is a Polystyrene capacitor of 270pF Maybe you want to go for this one instead of the 330pF Finally place two of these prepared Cinch connectors with the additional capacitors inside to the Load connectors on the rear side of The Grail That s it input capacitance matching for your MM MI
7. an authorized service point for repair van den Hu Phonograph Preamplifier The Grail 11 TECHNICAL SPECIFICATIONS Mains power Power consumption Temperature operating range Max undistorted output voltage Output impedance Input sensivity values MM input Amplification factor 33dB Amplification factor 41dB Amplification factor 50dB Input impedance MC input Amplification factor 56dB Amplification factor 64dB Amplification factor 73dB Input impedance available with 115Volts or 230Volts 50 60Hz 7 Watts from 15deg Celsius up to 30deg Celsius room temperature No condensing on item allowed Use only in dry rooms 25Vss Accumulator driven version 19Vss 330 Ohms real resistive given for 250mV RMS resp 0 707Vss output level on amplifier output 5 6 mV 2 2 mV 0 8 mV 47K Ohm 50pF 0 4 mV 0 15 mV 0 05 mV autom matching from appr 40 Ohms up to 400 Ohms van den Hu Phonograph Preamplifier The Grail 12 WARRANTY van den Hul Phonograph Preamplifier The Grail 13
8. cation factor by pushing the respecting levers to the on position van den Hul Phonograph Preamplifier The Grail Basically the higher the dB figure the higher the amplification factor and as a result the louder the music signals will be Don t overdo choose only an amplification factor that is really necessary Taking amplification factors much higher then necessary will result in a reduced overdriving capability headroom of the preamplifier This may result in a harsh kind of distorted sound in the loudest music passages Some final hints As all electronic audio devices The Grail has a pre aging period when bought as a brand new device Normally this ends after 50 100 hours of listening to music During this time the sonic quality raises to it s maximum As well if the preamplifier is cold was switched off for some hours it takes some time to be on the height of maximum sonic performance After appr one up to two hours of warm up time the maximum is reached Because of the low power consumption of The Grail of only a 7Watts you may want to keep it always on This delivers you the best sound anytime you would like to enjoy your music But e g if you have a holiday and you leave your house for days switch off your preamplifier as well as the rest of your audio chain In case of a holiday trip you switch off your cooking plate too don t you van den Hu Phonograph Preamplifier The Grail
9. ictly separated amplifier sections and circuit layout deliver a very natural soundstage inputs two phonograph inputs one for MC cartridges one for MD or MC high output a shielded transformer is placed in an external housing to avoid hum and EMI noise power supply with Gyrators for each amplifier stage deliver very high noise cancellation the external transformer is available for different mains voltages Designed to provide high end audio The Grail will deliver you outstanding sound quality with nearly every available modern phonograph cartridge van den Hu Phonograph Preamplifier The Grail SAFETY PRECAUTIONS Use The Grail phonograph preamplifier only for the designated application range it was intended for If the mains power cable or the external transformer housing is damaged and or inner wires can be touched do not touch theses cables and do not use the preamplifier Touching wires connected to mains live will harm your health seriously In case of this kind of damage do not touch the preamplifier or it s transformer box and unplug the mains plug immediately Bring the preamplifier to an authorized service point for repair To avoid risk of fire or electrical shock do not use the preamplifier and it s external transformer in rooms with high humidity or in other wet environments It may be used in dry places only If any kind of fluids water drinks soapsuds etc runs into the external transformer housing or into the
10. idges and 2 Moving magnet MM cartridges to this group belongs also the moving iron MI systems MC cartridges again divide into two groups a low output types and b high output types Examples a representative of the species b is e g van den Hul Grasshopper HI CHA with 2 25mV cm output voltage and a representative of the species a is e g the van den Hul Grasshopper III GLA with 0 6mV cm output voltage or the van den Hul The Colibri XCP with 0 4mV cm output voltage In practise for the high output MC systems please use The Grail s input MM Why Now this input is more then only a plain MM system input it is also dedicated to high output MC systems This way you avoid any overdrive of your preamplifier s input If you have a low output MC system please use The Grail s input MC It was especially designed for low and medium output MC systems And this input has a remarkable feature it matches the input impedance for your MC cartridge automatically Simply connect your low or medium output voltage MC system to The Grail s MC input and forget about impedance matching and all the rest just enjoy the music Impedance matching for high output MC systems connected to the MM input These lines are dedicated to the skilled users only if in doubt always consult your dealer Impedance matching is easy done stick to the cartridge manufacturers recommenda
11. input connectors MC or MM of The Grail These are item No 3 or No 4 of the picture of the rear side of the preamplifier Also connect the common ground cable to the ground earth connector of The Grail item No 2 of the picture of the rear side of the preamplifier If you have more ground cables e g coming from your system rack connect them to this ground connector as well Put the switch MM MC item No 1 of the picture of the rear side of the preamplifier to the direction named same as your chosen input Caution turn volume to minimum before switching Attention please turn your volume control level potentiometer on frontside of your control amplifier to the left side position quiet Now switch on your preamplifier The Grail with the switch on the rear side of the transformer box It will take about 15seconds and The Grail releases the output signal During this time all internal bias points are stable and the preamplifier is ready for listening That s it Put a record on your turntable choose the desired volume and enjoy the music van den Hu Phonograph Preamplifier The Grail 6 Choosing the right input Impedance matching Because of you have two inputs at the rear side of The Grail you have the choice between them but which one to take There are various phonograph cartridges on the market Roughly said they divide into two groups 1 Moving coil MC cartr
12. tion for your cartridge If it says recommended input impedance is 470 Ohms for your high output MC system use a high quality 470 Ohm resistor and solder it into a male Cinch connector Make two identical of them because of you are listening to stereo sound and that means two channels Place these two prepared Cinch connectors to the connectors Load at the rear side of The Grail item No 5 of the picture of the rear side of the preamplifier You re done van den Hu Phonograph Preamplifier The Grail 7 Impedance matching for MM and MI systems connected to the MM input These lines are dedicated to the skilled users only if in doubt always consult your dealer What about the impedance matching of MM or MI systems Normally everything should be fine The Grail s input impedance is 47Kilo Ohms 47000 Ohms this is the standardized value for MM MI cartridge inputs Just connect your cartridge and enjoy the music In very few cases the the input capacitance of the combination turntable signal cable preamplifier input is not high enough As mentioned this is rather uncommon Normally the input capacitance is just right or slightly too high if way too high use a better and shorter cable ask your dealer But in case the input capacitance is too low you may get an aggressive and too bright sound How to get rid of it You can do the same as with the matching of the high output MC
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