Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: mwelch55 on May 23, 2019, 12:48:28 pm

Title: Single Ended Dual Channel Negative Feedback
Post by: mwelch55 on May 23, 2019, 12:48:28 pm

I am almost finished building a single ended dual channel amp.  The amp has two completely separate preamps that doesn't share any of the same circuitry.  I switch between the two using relays.

My question is how to connect the negative feedback?  Can they both get their negative feedback from the same tap or separate taps?  How is this usually accomplished?

Mike

Title: Re: Single Ended Dual Channel Negative Feedback
Post by: sluckey on May 23, 2019, 03:23:37 pm

NFB is usually a power amp function. It's usual to only have one power amp so there's only one NFB loop. If you have something unusual, show us a schematic please.

Title: Re: Single Ended Dual Channel Negative Feedback
Post by: jjasilli on May 23, 2019, 03:26:18 pm

Ditto to a schematic.  In the typical guitar SE Power Amp, NFB is usually fed to the preamp tube that drives the Power Tube(s).  So I think the 2 preamps should drive that last small bottle tube.