Recap check - old fender

[FYL]

Using up old tube charts before making new ones is another classic Leo move.

My (original) Bandmaster Reverb has a nice (original) Twin Reverb tube chart...

[angelodp]

yeah my Super has the 5G4 sticker but all other indications are that it is a 6G4. I guess Leo and the gang were moving pretty quickly with tweaks. Bluzmike has the very next serial number up from mine in Germany and his has a standard 1/4" output jack and mine has an RCA.

[Structo]

RCA for the speaker jack?

I don't think I have ever seen that before.
Of course I don't get many 50 year old amps across my bench.......

[tictac]

Old paper capacitors are the one thing that should be replaced in the old Fenders if your going to play them. Collectors like "everything" original. I had a customer with a warehouse of old Fender amps and he had me go thru them and even replace any that had been modified with a 3 prong AC cord back to the original 2 prong cord... go figure

[angelodp]

What material are the Astron cap covers made of?

This amp also has TAS electrolytic cathode caps. Are TAS good quality caps?

[oldepicker]

Hey ange... how ya been?

One caveat I ran into: If you use the big blue Sprague Atoms, the 600V 20mF ones, check the dimensions and make sure they will fit under the Fender cap can. I bought some to do a Brown Super myself and when they came in I discovered the posted dimensions didn't correspond to the actual size... sucked!

Not trying to hijack but I have a dilemma that I could use some suggestions on. My 6G4 '61 Super is having a problem, the same as when I first got it as a project/restoration. It works good for the most part, but has some intermittent noise and crackling then a loss of volume... or you could say it has the lower volume (not a whole lot less than full volume) which occasionally displays full volume momentarily, then reverts back to the slightly lower volume... very frustrating. I replaced the filter caps to start with a fresh set and it still has the problem. I'm next going to check resistor values and run a circuit voltage check everywhere. I'm thinking cold solder joint or drifted component which will, hopefully, show up as a whacked out voltage somewhere.
Anyone have an idea where I might want to start or focus my attention.

It does it on both the Normal and Vibrato Channels, BTW.

[angelodp]

Doin good, playing the best damn amp I ever heard... Redplate, BlackTweedODS, sweeet. Doing some tinkering on a few amps and learning as I go. I am leaning twards the F&T which will fit, I got the dimensions. What caps did you end up with. Sounds like a cold solder joint for sure. Had that on my Dlite for a bit while I was doing a midcap switch and then I spotted the joint and presto. Any chance you can post a gut shot or two.

[Structo]

Another thing it could be in corroded or loose socket pins.

I would get some Caig contact cleaner and spray the pins of a tube then plug it in and out of the socket a few times then wipe off the pins.
While you are plugging it in and out, check out how much resistance there is when you push it in and out.
It should take reasonable force to push it in and out.
If not then you should try to re-tension the pins (discharge caps first of course) or replace the loose socket.

Bad grounds, bad solder joints even a flaky tube can cause the symptoms you describe.
Might have a cracked resistor as well that doesn't act up until things get hot.

[oldepicker]

Thanks guys, kinda my thoughts, but you know how those friggin' things go... always the last thing you check

Thanks Tom, I'll recheck sockets. I usually retension all as a 1st round of "things to do" on my list of resto tasks. I may have not done all the preamp ones though, as I usually start with the power tubes sockets and may have gotten distracted doing the preamp ones as the damn thing has 6 preamp tubes. Also one of the tremolo pots was frozen ( the oddball reverse taper thing) and I started scewing around with a bunch of things and forgot where I was.

I'll try and get to posting some gut shots, but it probably wont happen 'til tomorrow, been really busy lately and the amp stuff has taken a backseat to other things... but, as always, any help on this one will be greatly appreciated. Sometimes, you forget the obvious or get reminded of something you missed, and a suggestion points you in the right direction... THANKS GUYS!

[oldepicker]

oops forgot... I ended up going with some 500V Spragues, but really would have preferred the safety margin of the 600's.

[RightLurker]

I posted awhile ago, I think, that Weber has 20mF 600 volt caps. They aren't very big, and fit fine under a Fender filter cap cover. I don't know where Weber gets these, but they are similar in appearance to Illinois caps. I recapped a 6G6 Bassman with them, and it seems to be doing fine. Oh, and they aren't expensive.