Upgraded Tone stack module replaces monolithic ceramic type tone stack with discrete thru-hole capacitors and metal film resistors. Resistors are already soldered but Capacitors are not installed on this PCB. This allows purchaser to choose their own capacitors. Note that the through hole spacing is described in the picture gallery. Note that Not all tubular film capacitors will fit well on this PCB, so measure the capacitors you want to use before purchasing.  

For completed modules see my other auction:

https://www.ebay.com/itm/335040920091?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=VEscATZ2Sba&sssrc=2524149&ssuid=VEscATZ2Sba&widget_ver=artemis&media=COPY

 

The upgrade tone stack can be easily installed in many cases without even removing the control PCB,  the original module can be desoldered and pulled out,  and the new module installs on the rear as shown in pictures.

Replaces the CR-01 (1346837)  or PEC6470000 modules in vintage Ampeg SVT, Geminis, Reverberockets, Jets, etc. 

http://www.vintageampeg.com/ampeg-tone-stack-modification/

If your Ampeg amplifier was built in the 1966-1978 date range in the US, and has PCBs rather than eyelet boards,  it likely uses this module.