Soldano SLO loop mod hires gut shot

Jack Luminous

Well-known member
I was asked some times ago to post a pic of the loop mod I had done on my SLO. I took it out of the rack this WE so here it is. On the top right corner of the pic are the loop jacks. The pot just beside the jacks is the new master volume. the next pot with the big cap glued to it is the variable depth mod. Loop is after the tone stack. Normal and overdrive levels now act as individual loop send level for each channel. This mod doesn't change the tone af the amp and solves any problem or complaint one might have about the effect loop.

DSC_0862_1.jpg
 
Did you just go straight from V3 to V4 (as if nothing were in the loop) and then move the connections for the loop jacks to after the channel MVs? Or did you move V4 to after the channel MVs? Hope that made sense.

And is that a post-PI MV?
 
I did not do the mod myself, a local tech did it for $150 about 10 years ago. I think V4 was moved after the channels MV and the new master volume is indeed a post PI MV.
 
I was asked some times ago to post a pic of the loop mod I had done on my SLO. I took it out of the rack this WE so here it is. On the top right corner of the pic are the loop jacks. The pot just beside the jacks is the new master volume. the next pot with the big cap glued to it is the variable depth mod. Loop is after the tone stack. Normal and overdrive levels now act as individual loop send level for each channel. This mod doesn't change the tone af the amp and solves any problem or complaint one might have about the effect loop.

DSC_0862_1.jpg
Any chance you might still have the pic? Thanks
 
Away from home right now, until the 16th of august, will post it again asap.
Thanks a bunch! Sorry for digging this thread up again. I'm actually in the works on a SLO100 clone, and would be great to do these while I still can make a mess in the chassis and drill haha. Do you happen to have or know also the ''new'' Return pot level mod that exists on the newer amps? That would be cool also.
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The return level is just a potentiometer wired as a voltage divider with an additional protection resistor. One side of the pot is the return jack positive, the middle wiper goes to the return grid, other side goes to the protection resistor referenced to ground. The resistor is just to protect the high impedance grid from ever going positive - it needs to be 50k or so minimum depending on how aggressive the return stage is biased.
 
Look up the soldano decatone schematic and you will find the tube loop and how to implement it in your slo.
 
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