Bogen CHB-20A Conversion Schematic

[Platefire]

I am posting the Jpg file version converted from the SCH file of my Bogen CHB-20A conversion. I did a lot of searching on the net for any mod schematics previously done on this particular amp and there wasn't any I could find. There has been quite a few conversions found but none really documented on a schematic that included the Bogen amp set up. There are plenty of original Bogen schematics on the net. So for original Bogen component values refer to that. Even though I refer to this amp as the "Bopeg" because of the Bogen power amp/power supply and Ampeg Gemini II style preamp, I use the Bogen title in the heading so other folks that end up doing a CHB-20A can find it dong a search.
  I was searching for a preamp I could use to incorporate those existing long shaft 1 meg pots so I could continue to use that old rusty Bogen chassis housing and sluckey suggested the Ampeg Gemine II preamp which worked perfectly for this amp. Clean tone is my main sound and this amp can do that at a lower power level. You can also get some nice grind/breakup at higher volume levels or even lower volumes using the Master Volume. So I hope this is a help to some other Bogen CHB-20A converter.
   One more thing, I'm including the schematic of the Ampeg Gemini II preamp provided by sluckey because I changed some of the original component values slightly because I didn't have them in my inventory. So this schematic will show the true Ampeg values. Platefire 

BTW-A tweakable version of this schematic can be found on the other schematic Thread "PC Express and JSchem" but you have to download the free program to manipulate it.