Introduction the Super Squirrel Monkey 6AF11 amp

[iccaros]

I completed my test build out of a take on the Squirrel Monkey amp http://www.solorb.com/elect/musiccir...ey1/index.html
I have some weird things to report in this build, everyone I talked to online said to worry about internal oscillation so I used the first two triodes as the first gain stages, and then added a cathode follower with a 12AX7, just as a thought that if that is a problem then maybe separating the proceeding gain stage would help. I saw zero issues with Oscillation through use or on the scope. In the notes for the Squirrel Monkey, he shows a 10K:8. I have a Hammond 125CSE which will give me 10K on 4,8,16 ohm loads. I connected the 4 ohm tap as I have a 4ohm 12" that I use for testing. and It was ok, no Cab so little bass and well no Cab so you get what you get. But then to test when I thought I had an issue that turned out to the cable coming loose from the speaker, I plugged into a 8ohm 12" with cab, and doubled perceivable listening volume, so this amp seams louder @ 20K than it does 10K.
Measuring the Cathode bypass of 160 ohms I read 3.5 to 4 volts with the 4ohm load and it stayed in the 3 -3.5 v with the 8ohm. so about 25ma (total did not measure screen to subtract) and 23ma each

so at best this is a 4.5 watt amp..
It could also be that the 0ohm is more efficient, I have no ideal the rating of 4ohm is as it came from a line 6 amp I bought for $20 from Craig's list to take the cab from

I am open to suggestions, as this was a build to prove the tube works...
schematic
http://dl.dropbox.com/u/14312589/Sup...l%20Monkey.pdf

Thanks

[soundguruman]

It could also be that the 0ohm is more efficient
In the notes for the Squirrel Monkey, he shows a 10K:8.

I don't understand wtf you are trying to say.

[iccaros]

sorry for the type-o, my brains work ahead of my fingers
not tied together well, I was continuing on from the lines before, you will see I connected a 8ohm speaker to the 4ohm tap, giving me effectively 20K primary to 8ohm. But the 8ohm speaker is a 96db efficient speaker, I do not know the specification for the 4ohm, so I can not say that change in loading was effective in making the amp louder. Lately I have been using this @ 5K primary and it works fine, and is louder to my ears, I do not have a decibel meter and I see close to 4watts no matter what I set it at. As the Pentode in the 6AF11 is not designed for Audio, it maybe that 5K is the best we can do. I wrote Mr Cook who remeasured his OT, and found that it was 3.3K primary not a 10K as listed on his page.

So I was trying to say that @ 20K primary the amp sounded good, but with later test I now find that I like 10K better and 5K works just fine with no other changes.. So what ever OT you have with little tweaking will work, but I guess that is almost true on any amp.

[RWood]

Sounds really good! Nice job on the project.