TM36 Fx Loop and Reverb switching problem FIXED. The solution is here!

After some brilliant info searching and superb PCB work Vladi802080 came up with this description of a possible issue and the solution.  It was posted as a second response in an older thread but I thought it should have its own thread to make it more prominent and easier to find from outside the forum.

Here is the problem:  TM36 Switching Fixed  There isn't too much to see htere but there is a description of the fix.

Here is the solution:  Vlad's Fixed TM36  This is the thread where Vlad picks up and shows what is needed to fix it.  His posts are down the first page.

Great work Vlad, we are all grateful to you sharing this info.

ANYONE FINDING THIS AND USING THE INFO TO FIX THEIR OWN AMP, PLEASE OPEN A NEW THREAD TO GET MORE ADVICE ON YOUR OWN AMP.  ONLY ADD TO THE END OF AN EXISTING THREAD IF IT IS JUST A THANK YOU TO THE OP.  ANY NEW GENERAL UNIVERSAL INFO ON THIS PROBLEM NOT SPECIFIC TO YOUR OWN AMP COULD CERTAINLY BE ADDED HERE TO KEEP THINGS TOGETHER.

Details of the components used:

Zener diode - ZMM7.5, any 7.5V 500mW SOD80 package zener should do

Capacitor - 2.2uF/25V, general purpose tantalum in a standard sized package.  This value is what is in the GM36 but would be pretty much standard, 25V working especially.  Anything reasonably close to the original 2.2uF value would do and you could even increase that as long as the component size is the same.

HCF4053BM1 - Vladi802080 says he used a 74HC4053D version instead with good results.  All CMOS types should do.

That's the joy of designing correctly for general purpose universality and not "perfect boutique components".



GUITARISTS TAKE NOTE!  THIS IS ONLY A PROBLEM WITH SWITCHING LOGIC.  IT WILL NOT HELP YOUR TONE A SINGLE SQUIDDLY PLACEBO DRIVEN BIT TO ARGUE ABOUT CHIP ROLLING TO YOUR "GURU TECH'S FAVOURITE VERSION" OF THE 4053, OR ANY OF THESE COMPONENTS!  DON'T EVEN THINK OF IT, THEREIN LIES MADNESS!!!