Aikido linestage Help Needed

[Cambe]

Hello
I have two of John Broskies mono Octal PCB's and the PSU,PCB's that Bas Horneman did a group buy for, that uses the 6X5 rectifier tube. I don't know what transformer to use to get the B+ voltage of 300V and supply the heaters with the correct voltages needed. I am plan to use the 1578/6N8S tubes listed on ebay. I will use the Dale RN Series 1/2 W resistors. Are any WireWound resistors needed? I shoud still follow the parts listing for [6/12]SL7 & [6/12]SN7 listed in the Mono Octal PCB's instructions?
B+ Voltage = 300V
Heater Voltage = 6.3V/12.6V
R1,5,6,7,12,13 = 1M
R2,4 = 1K *
R3,9,10 = 300 *
R8, R11 = 390 * [Iq = 17mA]
R15 = 83.3K
R16 =100K
R17 = 0, Jumper
*High-quality resistors essential in this position.

C1 = 0.1 - 10 mF ( I don't know what value exactly to use).
C2 = Same "
C3 = " "
C4 = 0.047mF - 0.22mF "
C5 = 100 - 1KmF , 16V Electrolytic "
All capacitors ratings exceed B+ Voltage.
Sincerely,
Harry

 

[Burnedfingers]

Hi Harry,

If you have the boards that Bas made up then you will find that the resistor numbers are NOT the same as they would be for John's boards. Therefore you cannot use John's schematic to stuff the Bas board.

I will try to send a schematic for the 6N1P Aikido. You will find that the resistor numbers will be in the same position as they would be for a 6Sn7/6SN7 Aikido.

The top 6N1P tube shows a pin number 6 for the plate. The 6SN7 will have a pin 5 there.

Therefore the top tube will be 5 plate, 4 grid, and 6 cathode for the 6SN7 tube.

The bottom 6SN7 will be 2 plate, 1 grid, and 3 cathode. The tube pin out numbers will be the same for the other 6SN7 tube.

 

[Burnedfingers]

I will try to post a picture of the "Bas" power supply.

Note this is figured to give an output of around 220 volts if my memory is correct. I believe you will want to run your 6Sn7's with a 300 volt B+ supply.

 

[Burnedfingers]

Harry,

You will need a larger transformer than the 125-0-125 that is pictured in the power supply schematic.

I'm not much good at working Duncan's power supply program but maybe someone that is good at it will jump in here and help out.

 

[Burnedfingers]

I'm not much good at working Duncan's power supply program but maybe someone that is good at it will jump in here and help out.

Or maybe not

 

[SY]

We can simulate in PSUDII if necessary, but the exact voltage here isn't terribly critical. And a good thing, too, because some assumptions you might build into the model will certainly not be correct or can change (e.g., line voltage). If the exact voltage is critical, go high and use a regulator to knock it down to where you want it. The reg doesn't need to be fancy- the whole raison d'etre of the Aikido was to null out power supply issues.

For a nominally 300V supply, figure an RMS rating of 0.65-0.7 of that and the transformer conservatively overspec'd. Don't use a toroid. Full wave bridge. Use solid state rectifiers. Conveniently, that means a 220V winding used with a C-input pi filter. If you know the current draw of the preamp, we can try a few variations in PSUD making some guesses on values and avoid particularly bad mistakes.

edit: PSUD will not simulate the hybrid silicon-tube circuit shown in your drawing.