By request, I'm starting this thread dedicated to my ss combo conversions. Let me start by saying that I don't claim to be an amp guru, or that my ideas and designs are anything that hasn't already been done before. Or, even any good. I'm just an old rocker with a lifetime of experience with some practical and useful skills I can apply to amp building. To avoid taking my vintage Marshall 4010 to gigs, and preserve its condition and value, I bought an old Model 5210 amp that was listed as "not working" on ebay for its cab and chassis. I gutted the chassis, and special ordered a JCM800 build-it-yourself kit online that included all the parts, unassembled, no chassis. I figured I can drill holes, not sweat putting a ding in the tolex or grill colth, and mod, un-mod, and re-mod with no limits or fear of destroying any vintage value. I drilled and punched all the necessary holes to mount everything in the 5210 chassis, except for whatever holes already existed for pots and jacks. This first amp is named "Franky", which was also my dad's name (RIP Dad) Unfortunately, I can't find the pics documenting the progress of the build, but my later two builds, Franky Jr., and Lead 20 are well documented. They are also using old ss combo donor chassis's. So, some of Franky's pics are from Franky Jr's cab and chassis to show before and after. Franky looked like this before I dug in: No guts Making it holy Fast forward... Now with guts... Done! As we see here, I decided to make it a 4 hole Plexi instead of JCM800 with a couple more input jacks, and a few circuit tweaks. Hey, why not! Here we see the pentode/triode swith above the voltage and impedance selectors, as well as speaker and effects loop jacks So, Franky is a basic 4 hole Plexi with a JCM800 style pre phase inverter master volume, a pull bright switch on the preamp gain pot, an effects loop, a PPIMV, and a half power switch. Franky Jr is way more modded, and has classic tone iron, Sozo caps, tinned teflon wire, F&T filter caps, all the features Franky got, plus externally adjustable bias, 3 way switch for multiple negative feedback resistor values, and a multi voltage transformer using a 3 position standby switch to switch from standby to either high or normal voltage. Thinking about swapping the high voltage to the 3rd, low voltage option to brown the sound some and see what that sounds like. The most crazy mod I did on Franky Jr was to add a 4th preamp tube and a switch to reconfigure the bright channel to be either stock Plexi or JCM800. And, you can still jump the 800 channel to the normal channel for even more versatility. Here's some Franky Jr gut shots. Check out the labyrinth of shielded wire on the JCM800 mod switch. There you have it. I'll follow up with details on the Franky Jr. and Lead 20 builds when I can, along with some sound clips. Thanks for looking!