Posts Tagged ‘pot’

FX loop alternative

To the left is the previously posted alternative loop modification schematic to change a Mesa Dual Rectifier from a parallel loop to a serial loop.  It’s easy.  Most of the time required for the mod is spent taking the amp apart.  (Here’s a link to a 2 Channel Recto with the same mod.)

The following pictures are provided to show the inside of the amp, the job, and a crappy job someone did of soldering the output transformer to the daughter board.  I used a 22 gauge wire with the insulation removed for a clean, short jumper.  I’ve seen people use insulation for the job, but the space is tiny.  Note that my solder joints look a little matte.  This is from the lead-free, silver solder I used.  Almost every joint looks that way when I use it, no matter what, but it hasn’t been a problem.

Update July 2016: Verified.



Vintage humbuckers and those which emulate P.A.F.-style humbuckers have a distinct dip in the midrange, due in part to the unbalanced DC resistance of the coils and the number of winds on each bobbin.  Many modern humbuckers are over-wound, but still have an unbalanced pair of coils to produce a “P.A.F.-on-steroids sound”.  Many other modern humbuckers are fairly well matched, giving the pickup a spike in the midrange.  The Seymour Duncan SH-4 JB is one such pickup.  At a total DC resistance of 16.4k, it’s more than twice as powerful as a P.A.F..  My idea was to create a permanent offset and have a spin-a-split that doesn’t reduce to zero. (more…)

Anti-Log Pot Chart