Aikido LV ordered! Will be a fun project!

[cfcubed]

>  will probably start with 4 JJ ecc99 gold pins at 48V
 
And SSMH, related to one of holland's suggestions, operates at that voltage so maybe it'd be the easiest candidate to try:
http://www.diyforums.org/SSMH/schematic/SSMH-origPCB.gif
You'd have things to consider though, e.g. replacing the function the heaters play.

 

[digger945]

Quote:

Quote:

Originally Posted by Old Ducat1 SS /img/forum/go_quote.gif
 
Holland:
 
Check out the link in my earlier post, the sand HP driver comes after the output tube.  As far as I know, with my somewhat basic knowledge, is that if you don't mind a sand buffer after the tubes a low voltage Aikido will do.  If you want to go from the tubes to your phones you need a high voltage version.  My All In One LSA / HPA runs about 150 volts on the tubes, not too high compared to a monster tube power amp.

 
Thanks Steve.  I do not mind hybrids, in fact I quite like them.  At the same time I'm curious why it goes after the output tubes.  I can't say I'm overly familiar with his Aikido, I tried to follow up on it once, but it seems like his Tube Cad Journal is one tweak of the circuit after another, and it's hard to say what's better.
 
I'll P2P his input tubes directly into a push-pull mosfet buffer, when I figure out what his circuit actually does.   I don't like the cap on the output.  I think I remember this circuit.  I should probably test it, but I wasn't keen on listening to a LM317 as the output buffer.
 
Thanks again.

 


Quote:

Quote:

Not sure what to do now. I am very skilled at soldering, kit building, chassis design but a novice at best when it comes to audio circuit design Unless he has a kit out soon to make this LV good for headphone use as he described in a post then I guess I am SOL. Soooo irritated that I got the 24V and LV confused functionality wise... what I get for late night reading and a quick paypal trigger finger. 

There are a number of hybrids out there.  There is a generic diamond buffer, that Broskie didn't want to use, a JISBOS (JFET input/BJT output) buffer from AMB, Cavalli Audio used a SE BJT buffer for the SOHA 2 (which is a fine buffer IMO).  There are dozens of output stages you can steal, but they won't exactly be a glue.  You can even try his original LM317 buffer, though I would say the generic MOSFET SE buffer, with a CCS and a big cap on the end might sound better than the LM317.  I have no experience with the LM317 on the output though.
 
You can glue a MOSFET Source Follower onto this ciruit easily.
 
http://gilmore2.chem.northwestern.edu/projects/szeke1_prj.htm
http://www.pmillett.com/starving.htm
http://www.headphoneamp.co.kr/bbs/data/diy_sijosae/MHHAv2.gif
http://www.head-fi.org/forum/thread/402067/a-super-simple-6dj8-headphone-amp

After trying all that you mention, I liked the original single ended 317/cap buffer best. No difference much using depletion mode mosfets.
 

 

[holland]

Quote:

After trying all that you mention, I liked the original single ended 317/cap buffer best. No difference much using depletion mode mosfets.
 

Interesting.  You like it better than a servo'd buffer?  Having used output caps before, I'm not a fan.  Too much depends on the caps themselves, which can drive costs up.

 

[digger945]

It's been about 2 years now since I tried all that. I have used lots of different output caps and liked the blackgate nx 1000uF 25V the most. I now have DN2540 depletion mode in place of the 317's, with not much difference in sound. There are pictures in the older aikido thread I think.

It is very easy and fun to try different configurations with this amp. I like the single ended sound the most. Even with cheaper caps like panasonics, etc.

 

[Coreyk78]

I'm using Blackgate NX for the output caps in my 24V Aikido, they sound great to me