Ceriatone Forum

I know some amps have a switch to defeat the neg feedback, has anyone tried this? I guess it might get uncontrollable on OD

However, the neg feedback loop originates from the OT 4ohm tap. Is there any reason why? and why not the 8 or 16ohm taps? What would be the effect of swapping.

you can easily do the mod and try the effect...
the sound will be much brighter and bass heavy, in a single word, scooped.
there will be more gain and volume, but I suspect that a Dumble style amp without neg fbk will not sound so good.
NEG FBK is used to narrow the frq spectrum, flattens the amp response and tame the gain...if you took the neg fbk from an higher ohmage tap, such as 8 or 16, and you left unvaried the remain of the loop circuit, you are injecting a larger tension back to the PI.
The result is a darker and flatter sound, less gain and a bit less volume...
An interesting mod is to put a pot in series with the tap and a swtich to select between various taps.
with the pot you can esasily control the quantity of neg fbk going back into the circuit and with the switch you control where to take this fbk...
I've done this mod on my sloclone amp and it is very useful.

Thanks for that. I think I understand! the 4ohm tap has the lowest output so will have the least effect (other than no loop at all) 16 ohm will have the biggest effect. I might just try your mod, or just use the ground switch (non-operational) to switch the loop off and on.