Y A A B - Yet Another Aikido Build

[Cappy]

Whereby I construct an Aikido output stage for various DIY DACs.

In this thread I will make vain attempts to build a good sounding non-resonant LCLC power supply, fumble around with grounding, experiment with different tubes and dissipations, clumsily interface with some Twisted Pear and PCM63 DACs in different ways, recklessly compare CREE diodes against tube rectification without the benefit of blind testing, and more.

Suggestions, corrections, ideas, or poignant personal Aikido experiences are encouraged.

I’ll be using Broskie’s fabu boards. Attached is a picture with composite teflon sockets installed. I wanted to use teflon and was able to find some nice PCB mount ones at DiyHifi Supply:

http://www.diyhifisupply.com/diyhs_sockets.htm

Note: Expect this project to move slowly while I gather parts.

[woodturner-fran]

I've built 2 now - both using his boards. One is a regular 24V aikido using 6GM8 tubes and the other is the newer version 24V one with the headphone amp built in.

Both are excellent performers. Top quality - don't think you'll be dissappointed.

Fran

[Cappy]

Fran,

Thanks for the encouragement.

Here is a question for you. I am looking at the Aikido manual now and there is a cap C3 on my mono board (C5 on stereo board) that is B+ to ground.

What is the purpose of this cap? Bypass of larger power supply final capacitor? Or does it serve another purpose?

[woodturner-fran]

God, right now I couldn't tell you - I remember something about it though - I think i used either 2.2 or 4.7uf wimas in there.

Fran

[JoshK]

Originally posted by Cappy
What is the purpose of this cap? Bypass of larger power supply final capacitor?

Yes as I understand it, it is a PSU bypass cap.

[Cappy]

Josh,

Thanks.

******

I'm going to use DC on the heaters. I have very efficient horns and want as little noise as possible.

Parts are starting to arrive. Here is a picture of the Tentlabs IDHT Heater Supplies I'll be using:

[woodturner-fran]

What tubes are you going to use?

Fran

[Cappy]

I'm definitely going to try 5687s in the second position, as I like them and have a good variety of them.

I'll also try 6n6ps in the second position. I acquired 75 of them a few years ago in a Ukrainian drug deal gone wrong. I hope they sound good in the Aikido as they are a lot cheaper than Tung-Sol square getter 5687s. See the picture below. The weird tube/socket thingees are 6n6p to 5687 adapters I tried with my tube amp. I may not use the adapters with the Aikido as Broskie provides a lot of configurability and I can add jumpers to the board to switch the heater layout.

People seem to like the 6CG7 in the first position so I'll try a few of those. If anyone has a recommendation for a particular 6CG7 (or 6FQ7) I'd appreciate hearing it.

I've got some 6DJ8/6922/6n23ps so I'll try those in both positions.

My system doesn't need much gain in the DAC stage so 6n1ps probably won't work well. I'll try them anyway since I have some.

I don't know nothin' about the 12**7 valves.

I'm going to install jumpers on the boards so I can clip in different cathode resistors.

[Stixx]

Hi Cappy,

your heater current requirement with the tubes listed (6CG7 and 6N6P) will be in the vicinity of 2.8A... Is the Tentlabs module up to that or will you be using two of them?

I'm asking because I once had a look at the Tentlabs also...and the one listed on the Tentlabs site now is only capable of 1.5A max.


---O

[Cappy]

Stixx,

Good point to mention this, in case anyone else wants to use them.

I'll be using two, one for each mono board.

Bill