high gain amp attenuating

[wouter]

Hello,

I am trying to design a high gain amp with 4 12AX7 gain stages.
My question is do you need to attenuate the signal after every gain stages and how much?

[J M Fahey]

merlin wrote a nice book about that, Kevin Connor too, there are others.

If you are serious about your quest (looks like you are ) , I suggest getting a couple good books and read them cover to cover.

There's simply way too much data to be able to condense it in a few Forum posts.

If while you read you get trouble with something, feel free to ask, but otherwise we will be repeating the same basic stuff over and over.

Just as a mini answer: rather than "attenuate after" a stage, what you actually need is to add some network "before" the next grid, because any signal larger than roughly 2 V will get rectified, clipped, shift bias and operating point big way, symmetry, but worst of all, will *easily* block that stage, causing horrible stuttering "blocking distortion" .

So most such networks are carefully tuned (there's not a generic formula) for optimum sound, which is often a compromise and not exactly what the designer wanted.

[Justin Thomas]

Hey Wouter & Juan,

There's a parallel thread in the Theory & Design section going on. Might wanna pick a thread & stick with it so nobody gets lost... Leo's already jumped it. Doesn't matter which one you follow, but one will keep everyone from shuffling and maybe getting frustrated and mad...

Justin

[J M Fahey]

Cool and thanks forn the advice

Yes, similar threads like these should be unified, one way or the other.

Maybe some Moderator can do that.

Just in case:

POST IN THE OTHER ONE MENTIONED ABOVE

[g1]

Here is the link to the other thread:
http://music-electronics-forum.com/t39052/