FX Loop mod for Trans-Atlantic?

[fredp322]

Does anyone know if there are any plans for an FX loop mod for the TA-15 or is it even possible? I absolutely L-O-V-E my TA-15, but, I'd sure love a loop, as well...just asking.

 

[94Tremoverb]

It's not possible - or not if the circuit is what I think it is, anyway. As far as I understand, the master volume is a Matchless-style Vox derived post-phase-inverter type - if so, you can't put an FX loop after the distortion (the only place it's really useful) because at that point the signal is split into two halves. It's not just a question of space or cost, although both of those would be a problem is such a small amp too. I'm sure that if it had been simple, Mesa would have put the loop in - it's part of their normal design brief, and they even fitted one on the Blue Angel where it's completely useless because the amp was specifically designed to *only* distort at the power tubes.

In theory, you could do it by having *two* separate FX loops, one for each half, and using a true stereo FX processor set to dual mono - but that's so inconvenient and restrictive that I doubt anyone would think it worthwhile. I know there are some amps with PPIMVs and loops - including Matchless - but the loops are in front of the distortion and don't really work very well. I guess you could fit this type of loop to the TA if you really wanted... just don't expect it to give you exactly what you want.

 

[fredp322]

Thanks! I appreciate the explanation. It's not a big enough deal to risk the safety of the amp, anyway...

 

[Deaj]

Well, the design works well and the amp sounds great. I wasn't aware that the master volume ia a post phase inverter. It certainly explains why a loop wasn't part of the design. It's a shame though - after demo'ing the Trans-Atlantic I walked away with the thought that I'd grab one if it had an effects loop.