Hi There Mateys! I be back to the forum. I know I haven't been posting in years, somehow I lost me password and had to re-register with a different username. Been checking the site off and on, and keeping up as best as I can. Congrats to TV on all he's accomplished and for keeping this thing going as we all don't post as much as we used to.
Anyway, reason for this particular post is twofold, one to say hi to everyone that I used to talk to on here and two to get some advice on a 63 6G6-B blonde Bassman that I recently picked up. It's in really good shape for its age and it is, LOUD, about matches my 100W Marshall at 5 at a volume level of 2! All transformer codes are original specs. It does have the Jensen speakers and I may switch them for Celestions but I haven't found the English ones yet, and I am leery of using the newer Chinese ones per TV's advice in one of the other posts. I'm including a couple of pictures of the circuit, as it looks like pretty much the original parts in the amp.
So, couple of questions for my own knowledge, as I have every intention of maintaining/restoring this amp. and playing it myself i.e. I'm not trying to resell it to Captain Teague!).
#1: The brown/red capacitors on the normal channel circuit, are they the original spec. ones that Fender used in the 60's or have they been replaced? The other ones look like the original Astron and Blue caps that would have matched the amp. I do need to clip out the one little cap. going to the Bass Channel (per TV's suggestions) get my Voltmeter out and check the voltages/capacitances across all the circuits yet, haven't done that yet and I'm sure some of these have drifted from original values, but from checking the circuit it looks like the previous owner kept the amp. as a 6G6-B and didn't Blackface it (thankfully).
#2: Preamp tubes are not the preferred Ruby AX7's. Actually 3 12AX7's (USA made) and one ECC83. Not sure of the manufacturer. I ordered some Ruby tubes and plan to change them out. Power amp tubes are large bottle Russian Gold Aero. 6L6WGB/5881's. Are they much different from the NOS 5881 Tungsols? So, next question, do I need to re-bias if I switch out just the a) Preamp tubes, b) the 5881's or c) both? If I do have to re-bias, where is the fixed bias-pot for adjustment on the 63'? I've worked with high-voltage circuits before, so I'm aware of the risks, and although I may take it to a tech., I'd rather do it myself. Any of those amp-bias kits out there make the job any easier or safer?
#3: The amp is great. Should have got one a long time ago. When I first started playing it, I let the tubes warm up for about 5 minutes on standby before I started playing. However, for the first hour or two the signal would cut out intermittently. I switched input jacks (1 to 2) on the normal channel and went over to the Bass channel as well, and I can't seem to isolate it. Changed guitar cables too, thinking that was it, but it didn't have any effect. Only thing I have plugged between the guitar (Fender Gretsch SSU) and the amp is the RE-20 pedal (I know, I know, I'm breaking the rules here with a digital pedal
). After a couple of hours it seemed to have stopped or else I didn't notice it anymore. I didn't try it with a different guitar, but that's the next variable I need to iron out when I get a chance to play again. Any idea what's causing this and how to fix it? My thoughts were either cable, the guitar input jack, or the amp input jack, but I figure I'd ask the experts.
I'm trying to post the images but not sure if that's working or not, having some issues with it. Might need some help on that too.
Anyway, no rush on replies, if anyone has any suggestions/answers I'd appreciate it, if not, no big deal. Hope everyone's doing well.