I have a Sonic ll schematic from 11/67, and it's identical to the 200S and Sorado, with a pair of KT88's; the "big brother" of the Sonic l (Sonic l-40 w/ a D140F) which was an EL34 amp.
Another example of the amps being named for the
combination of amp and speaker as was the Sunn practice in the 60's.
If it calls for KT88s and a 6AB8, it's a 60 watt. If it calls for EL34s and a 7199, it's a 40 watt. The three knob chassis is usually considered a bass amp because it's the same as a 200S but there's no reason not to use it for guitar if you like the sound.
So ecletiq, you have the probably the
most common Sunn "amp" from that era with maybe the
least common "badging"
Mine is SN # 2376. Is it worth any $$ to anyone but me?
Do you want to sell it? Post it in the classified section or put it on eBay, but be sure to mention it's identical to a 200S because more people are familiar with the 200S and they are generally considered to be excellent amps.
Mine has a slight hum. Is that normal? Possible culprit?
Could be a lot of things, but the most likely candidate would be the filter caps.
I bought mine years ago...
When were the electrolytics last replaced?
It's got a SS rectifier (sigh) and was wondering if it's worth the $$ to get it back to original? I'll probably do it anyway.
I can’t speculate on whether it’s “worth” restoring to a tube rectifier, that’s a decision that only you can make, but if everything is there it’s not a big deal to switch it back.
It probably has a tighter bass and maybe 10-20 more watts with the SS rectifier though.