Golden Age COMP-3A schematic request

thekid777 · May 24, 2020

Hi Diy
I'm searching for the COMP-3A schematic
it is like the la3a but there's some different things added which I need to troubleshoot
Thanks

rjb5191 · May 25, 2020

Weirdly enough im looking for the same thing. Im going to pop some nos trannies in there and upgrade the coupling caps, etc...i bet the la3a schematic is pretty close; ill know more tomorrow when i poke around. I also emailed Bo with golden age requesting the schematics although i dont have high hopes.

pucho812 · May 25, 2020

for first glance looks to be an LA3a with all the ed Evans mods.

rjb5191 · May 26, 2020

pucho812 said:
for first glance looks to be an LA3a with all the ed Evans mods.

I heard from Bo today and this is essentially correct but there are some relays that aren’t there in the original as well as the regulated power supply but they aren’t too hard to trace out. The transformer pinouts are a bit different and the Chinese tranny’s aren’t color coded the same as the originals but they are easy enough to ohm out. Im in the process of installing the original urei iron to upgrade my comp 3a. I just swapped the B11148 in tonight and i like what im hearing. Better clarity and some upper mid presence and sparkle. Ill get the B11178 in tomorrow!