I want to share some of the experiences I had while doing this project. I got back into DIY last year after a 40 year hiatus, after arriving at no where to go and all day to get there, HA! During that time, I built the AK Indignias, the AK Minimus XO mods and stumbled into a cherry Scott 222C and a Scott 350B tuner. Along the way, UPS has delivered a Hakko 936 soldering station and a Harbor Freight DMM. Listening to the Scott was delicious, after many many many years of very big solid state muscle amps.
I double checked everything while working through assembly. I measured all the resistors prior to installation and inspected every solder joint with a magnifying glass. I went back and measured every resistor after soldering, to see if any had values changed by the heat. I checked every chassis connection prior to power up.
Well, I did make a few errors but managed to catch them by double checking each step. Even managed to lop off one of the tranny leads too short after having the church ladies pounding on the front door and refusing to take no for an answer. Fixed with a splice and shrink wrap. You can see it in one of the pics. I mounted V1 with the wrong orientation of the octal groove, easy fix prior to attaching any wires. The right channel filament wiring to the driver board went astray, again, an easy fix. A slight hiss from one of the channels was again an easy fix, rerouting the AC heater wiring. Per Bob Latino, attaching the dummy stereo/mono switch, was tough, due to the lack of space between the driver board and the chassis. Super glue the nuts to the switch prior to attempting the assembly of that part to the front of the chassis.
The large Russian coupling caps presented some challenges as was expected. I shrunk wrapped the bias wiring and pins on the octal sockets attached to front of the chassis used for bias taps, I also cut off any of the tube pin tabs that were not needed. This was done to eliminate the caps from shorting the bias taps, as the big Russian caps have an exposed steel jacket. If I were to do this again, I would also shrink wrap the caps to insulate them from making any unwanted connections to the circuit board or the bias taps.
I used 20ga silver coated copper Teflon insulated mil spec wire instead of the supplied wire.
I want to thank Bob Latino for the great product and for the excellent customer service. I had a lot of questions before and after the purchase, and Bob always responded by Email within minutes, no matter how many times he has answered that same question from other newbees.
As you can tell, I like this amp a bunch. She has 50 hours to date. I expect that I would need at least 100 hours burn in time for the Russian coupling caps. Then the tube rolling begins. Siemens, Mullard, GE, RCA black plates, Telefunken, Sylvania, and Raytheon 12AT7s stand at the ready. A quad of new production Gold Lion KT-66s is next on the list. Thanks to AK for this excellent forum!