GlassWare Audio Design

9

Typical Part Values () Parentheses denote recommended values

 

 

 

6CG7 & 6DJ8

6CG7 & 6CG7

12AU7 & 6H30

B+ Voltage =

170V - 250V (250V)

200V - 300V (300V)

200V - 300V (150V)

Heater Voltage =

6.3V or 12.6V

6.3V or 12.6V

12.6V

R1,5,6,7,12,13

=

1M

1M

1M

R2,4

=

270 - 1k (640 5mA)*

470 - 2k (640 5mA)*

470 - 2k (741 3mA)*

R3,9,10

=

100 - 1k (300)*

100 - 1k (300)*

100 - 1k (300)*

R8,11

=

200 - 330 (291 10mA)*

200 - 470 (240 10mA)*

200 - 470 (74 30mA)*

R15

=

87.3k

83.2k

76.5k

R16

=

100k

100k

1 00k

 

 

*High-quality resistors essential in this position

 

 

 

All resistors 1/2W or higher

 

 

C1

=

47µF* Film for 300-ohm HP

Same

Same

 

 

470µF* for 32-ohm HP

Not recommended

470µF* for 32-ohm HP

C2

=

0.47µF* Film or oil

Same

Same

C3

=

10 - 1kµF, 10V Electrolytic "10 - 1kµF, 16V Electrolytic

 

C5

=

1 - 10µF*

"

"

C6

=

0.047µF - 1µF* Film or oil

"

"

C7,8,9,10

=

10µF-1kµF, 16V Electrolytic

"

Same

C11,12

=

0.1µF 160V(optional)

"

None

 

 

*voltage rating must equal or exceed B+ voltage

 

(input) V2, V3 =

6CG7, 6FQ7

6CG7, 6FQ7

12AU7, 5814, 5963,

 

 

 

 

6189, ECC82

(output) V1, V4 =

6DJ8, 6922,

6CG7, 6FQ7

6H30

 

 

7308, ECC88

 

 

Assembly

Before soldering, be sure to clean both sides of the PCB with 90% isopropyl alcohol, wiping away all fingerprints. First, solder the shortest parts (usually the resistors) in place, then the next tallest parts, and then the next tallest... Make sure that both the solder and the part leads are shiny and not dull gray. Steel wool can restore luster and sheen by rubbing off oxidation. If some of the parts have gold-plated leads, remove the gold flash before soldering the part, as only a few molecules of gold will poison a solder joint, making it brittle; use sandpaper, steel wool, or a solder pot. NASA forbids any gold-contaminated solder joints; you should as well. (Yes, there are many quality parts with gold-flashed leads, but the use of gold is a marketing gimmick.)

Normally, such as when the PCB sits on the floor of its chassis, all the parts sit on the top side of the PCB (the top side is marked). If you wish to have the tubes protrude from holes on the top of the chassis (and to place the PCB within 1" of the top panel with the aid of standoffs), then all the other parts— ex cept the tube sockets— can be placed on the PCB’s backside; it is a double-sided board after all (be sure to observe the electrolytic capacitors' polarity and glue or tie-wrap heavy coupling capacitors to the PCB).

Let me know what you think

If you would like to see some new audio PCB or kit or recommend a change to an existing product or if you need help figuring out the heater jumper settings or cathode resistor values, drop me a line by e-mail to the address above (begin the subject line with either “Aikido” or “tube”).

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HP Aikido Stereo 9-Pin B manual Assembly, Let me know what you think