Aikido Built At Last!!

[kianbach]

Comments please...............6DJ8/6SN7
B+ 300v
6DJ8 Cathode R 480 ohm
6SN7 Cathode R 470 ohm
Output cap 0.33uF

SOUND----SWEEEEEEEEEEET!!
Sorry No pics of inside.....FAR TOO MESSY!!It's a rebuild of another 6sn7 linestage I built 2 yrs ago.

ANY suggestions as to my next one also direct coupled 300B or 2A3 power amp to go with.....
Thanks,Kev

[kianbach]

here's a closer look..........

[Cycline3]

Looks great. I'm a big fan of the 6SN7 too. I can never get tired of looking at tube gear... way to go! Congrats!

[Bengali]

for the aikido line stage power supply, is it better to use electrolytics or the Solen Metal Propelenes?

thx

[kianbach]

I've used ASC polyprop in oil and sprague atoms in the CLCLC psu for my aikido.!10H x2.After the regulator I've split the HT rail and regulated further with 1/2 a 6SN7 per channel.It's overkill maybe but it's dead quiet.Hum is in the microvolt range and of course DC filaments throughout....Sound is AMAZING.Vocals especially.

[Bengali]

Did you use PSUD II to simulate your values? I trying to build the power supply for the Aikido and really need help. I attempted to do a simulation on PSUD, attached is the file. I'm still learning on what to look for.

I just used the Panasonic EETED2W221CA 220uF 450V (.603 @ 120Hz, .271 @ 20Khz) since I could easily find the specs.

Hope you or anyone else can help answer these questions:

1. How to find load of Aikido Line Stage (All 6GC7)?
2. Is it possible to add series dropping resistor in PSUD?
3. How to find transformer source resistance if not shown on spec?
4. Cap Resistance in PSUD is the ESR of the cap?
5. PSUD shows 280V at V(R1), how to acheive 300V without changing transformer voltage?
6. How does the other variables in PSUD help you to better design the power supply?
7. How accurate is the PSUD Simulation? Is the voltage off a lot or pretty close to it?
8. Assuming 230V at the transformer x 1.42 = 326.6, total drop of 46.6V through the caps and chokes, is this realistic?

Thanks for your help. I would like to finish my Aikido as well!

[kianbach]

From looking at the nine pin manual I assumed a current draw of 30mA total which in your psud file gives a B+ of 300.42v I've attached the file....As for working out the resistance of the transformer what I did was measure the R of the primary and secondary windings and input the values into the transformer specs in PSUD.By the way I usually use valve rectifiers which means higher voltages.

[SY]

Did you use no-load or rated secondary voltage? You need to know the former, and it's rarely specified, so must be measured.

[kianbach]

I measured the no load voltage for my aikido mains tranny at 330v then workked out the drop to feed the regulator with 310v .Also I have a 2k5 pot in each channel after the 6SN7 so that I can adjust B+ from225 to 300v.

[SY]

In my tests of the Aikido, the higher the supply voltage, the better the performance.