Local negative feedback switchable?

[Tdale]

I'm planning to use a swith in the local negative feedback circuit, so I can easily switch in on or off. Is there any problems involved in doing this?

Is the second clean stage the most used place for the NFB?

Tommy

[Funkalicousgroove]

That is a standard feature on two-rock signature amps, but it may "pop" if you switch it while the amp is on.

[Bob-I]

I have it on my Princeton 6V6 version. It works great, no pop and lots of great tones. I used a 3 position on-off-on so I can select either 22M or 44M.

[pamaz67]

the delicate ting is to keep the feedback connections as close as possible to the socket. I mean, no more than 1 inch long connections. Longer connections are a great source of troubles/noises. This, of course implies ( unless you do it via a relay) that the switch cannot be in the front panel.
Ciao

Paolo

[Icetech]

what bout switching the main NFB? I kinda like how nuts my amp gets in OD mode with the nfb unhooked:)

[mhuss]

I use a MOSFET switch to switch the NFB in and out on my 18watt/trex, because the 18watt side sounds dull with NFB and the trex side is out of control without it!

http://mhuss.com/18watt/schematics/MosfetSwitch.gif

--mark h

[Darkbluemurder]

I have it on my Guyatone D-clone. It is wired as follows:

Plate - 0.047uf cap - 10M res - 10M res - grid. The junction between the 10M resistors goes to the switch, the switch either grounds the junction or does not connect it to anything.

In this amp I prefer the NFB off because it sounds warmer. In the Bassman clone the NFB added to the sound by subdueing the midrange. In the Concert and the Deluxe it does not seem to have any noticeable effect.