Emohawk wrote:
I would like to have a loop in all my amps. I'm planning on adding one to my 2204, but it's pretty simple in that case (being a single-channel head). I expect it would be relatively straight-forward in the Triwatt too (insert the loop before the master volume)...
Especially as the Triwatt, unusually for most amps, but like all Hiwatts, has a further preamp gain stage after the MV which makes for a handy FX recovery stage.
Emohawk wrote:
The problem with the 18w, TC-15 & probably the Deluxe as well is you have two physically separate channels, as it were. One could easily add a loop for each channel. However, I've never understood why a loop couldn't be inserted after the channels get mixed prior to going to the output stage.
The 18W and TC15 (as well as AC15 and AC30) mix the channels together inside the phase invertor, which directly drives the power tubes. So there isn't anywhere to insert the loop "after the channels get mixed prior to going to the output stage". Basically the loop has to be inserted before the phase invertor. The Deluxe mixes within the preamp, so it doesn't have this problem.
Emohawk wrote:
... did I read somewhere that one could use the "jumper" between the channels as a parallel loop & use the volume of the jumped channel as a return/mix level or something like that? Still sounds like you're basically inserting the effect before the input stage though, so I don't know that you'd be gaining anything.
Yes, that's mainly something used with classic/tremolo 18Ws, and basically provides a kind of parallel FX loop between the inputs of the channels. You can'tdirectly jumper the two channels of a classic/trem 18W together, as they're out of phase, so you need some kind of FX in between. This doesn't apply to TMB versions.