Adding a NFB loop with Master Volume Guit Amp...Ack!!

OK you guru types,
I have a snappy tube guitar amp put together with a post PI master volume, and I would like to stiffen it up by putting in a negitive feedback loop into the PI.  BUT, I distinctly remember reading NEVER put any tone or volume controls after the NFB loop.  It makes sense, since the NFB would then not match the signal it is buffering, thus adding some additional unwanted(?) distortion.  But I have a vague recollection of seeing this done on existing circuits.  Thoughts, comments??

Thanks!!

> I distinctly remember reading NEVER put any tone or volume controls after the NFB loop.

"Inside the loop".

And have a beer, un-distinct your memory.

When you need the FULL benefit of NFB, and use a LOT of it, loss or tone systems inside the loop are counter-productive.

> snappy tube guitar amp

Geetar amps are different. Especially tubes (which I assume from your tooby terminology). A "Lots of NFB" amp may as well be transistor: LIGHT and cheap.

The amp already works with no NFB.

What you want is a "little NFB". Just enough to take some of the "raw" out.

If you then turn-down inside the loop, the NFB goes away. But that is very tolerable. The raw comes back, and as the turn-down makes it impossible for driver to overwhelm power tubes, the maximum output goes down. Which "is stupid" in conventional engineering (why buy/build a big amp for a small job?), but very useful to practicing guitarists.

Just do it. If you don't like it, you can take it out.

Sorry for off topic...
T.J its Ian From Cincy! email me at ghostbabymusic (at) gmail (dot) com

never liked the presence control either, don't know why, just don't hear anything good,

PRR, I don't know what they are paying you, but it's not enough.  (I can put that on my letterhead and mail it if need be)    Thanks for the shot in the arm.  Yes, tubes: a given where I come from, haha.

And Ian, email sent: what, 15 years???  This interwebs is teh bomb!

or companies adding  " resonance & texture " controls