[greggf]

I have a friend building what he calls "an Aikido-influenced design" dedicated headphone amp - Class A triode OTL no feedback.

I'm not a DIYer and have no technical background. Can anyone explain what this means - its implications in terms of operation, sound potential, and so on?

I believe he intends on using 12AX7 and 6S4A tubes.

I've searched here and on the web on "Aikido" and have found John Broskie's website, but, uh, don't understand much of what it says, at least until he whips out his Sennheisers and starts talking about sound.

 

[m0b1liz3]

Yeah, that is the problem with his site. It is organized like a blog and hard to search through to find info. It could really be improved with a different format such as menu systems and summarized articles. (and possibly a small forum discussing builds) He could then just archive the blogs for those interested in how the amp was developed.

There are a few people on head-fi that have built the aikido. I believe someone has built both a millet max and aikido and preferred the aikido from what I remember.

Aikido is a martial art that focuses on using the opponents energy and redirecting it back at them. Perhaps this has some meaning to the circuit?? I have heard this amp works well as both a preamp and a headphone amp and utilizes higher voltages than the SOHA and Millet. Either than that my technical knowledge is limited.

 

[philodox]

12AX7 - I'd stay away from most of the old preamp tubes if I were you, there are better choices.

Not familiar with the 6S4A though... Quote:

Originally Posted by m0b1liz3 /img/forum/go_quote.gif Aikido is a martial art that focuses on using the opponents energy and redirecting it back at them. Perhaps this has some meaning to the circuit??

Actually, I think it does. I'm not very technical either, but a friend of mine on here [looser101] was one of the first head-fi'ers to build the Aikido and explained a bit to me. I think it samples the power supply noise and then injects it back into the audio signal to cancel it out... or something like that. The effect of this is that it somewhat removes the power supply as a factor in the sound of the amp. It will sound almost identical with a small PSU as it will with a nmaher style tothetits PSU.

Great amp by the way. If things hadn't worked out with my current beast, I wouldn't have to look far for a replacement in a balanced/overthetop Aikido.

 

[looser101]

HOW AIKIDO WORKS

The diagram in the How It Works section explains it for the reading comprehension challenged. The red squiggly lines are a representation of power supply noise.

Hope that helps.

Renato