Cap age

[trem]

Just wondering if these caps are new(ish) .?
Obviously they are not the originals. But is it possible they are so old that it might be a good idea to replace them again.? Or is it more likely these are in the 2-7 year old range.?
Thank You

[Prairie Dawg]

It's hard to say since that plastic wrap has been used for the last 30 years or so. Dump 'em and know for sure what you've got, that knowledge will come in useful when the inevitable trouble shooting sets in.

[Gtr_tech]

There should be a date code somewhere on the casing. It may look like "95-15", which would be the 15th week of 1995. They don't look that old to me, so I wouldn't be too concerned unless you have hum problems.

[Prairie Dawg]

I ran into a problem with that a few months ago. A guy brought a Deluxe Reverb that had been 'recapped' a year or so ago. Turns out the caps were Mallorys, shelf stock that were unused all right but thirty years old. I'm looking at if from a 'get a baseline of known good parts' standpoint. As Enzo says, never make up an excuse not to check something.

[trem]

I ran into a problem with that a few months ago. A guy brought a Deluxe Reverb that had been 'recapped' a year or so ago. Turns out the caps were Mallorys, shelf stock that were unused all right but thirty years old. I'm looking at if from a 'get a baseline of known good parts' standpoint. As Enzo says, never make up an excuse not to check something.

......I'm going to ditch those things. They have been in there for several years I think.
Do you think I can get away with 450 volt caps for the screens.? Other than IC (do not have a problem using them, but I have several 22/450 caps) I am not sure I know where to get 500. I guess F&T would make them.......I suppose I can use my stock of 22/450, and if the screens are running more than that, I will have to make a change.
This amp is almost a gut job anyway. Let's just "do it right" so I do not look like an idiot when my friends re-built amp hums like bee hive.
Thank You

[Prairie Dawg]

Seeing as it's a Bassman running Bassman voltages I'd err on the side of caution and run the 500v caps, F&Ts should prove satisfactory but Illinois are pretty good as well, as are Nichicons and Xicons and Sanhwa-these last are very good stuff and I've put them in a number of amps with good results.

[R.G.]

As a side note, I love using an ESR meter to test caps. It's the only way I know of to actually see past the raw capacitance to some of the relative quality of the cap. An ESR meter can tell you that a cap is definitely bad without turning the power on or disconnecting the cap from the circuit.

Of course, it doesn't tell if a cap is going to go bad soon, just whether it's already going south.

[trem]

R.G. -
Is that what a Capacitor Wizard is.?
Those seem like a pretty good tool.....
Thanks

[Prairie Dawg]

I use an ESR Micro 3.1 that I got from the builder in Russia. Works like a champ and a useful piece of gear. The builder solders sewing needles onto the alligator clips so that you can poke right through the lacquer and into a trace.

[jrfrond]

Hard to say, but I'd DEFINITELY dump the cheap caps on the right. At least the blue ones are good stock (Cornell-Dubilier).

You know, everything works right up until the time it croaks, so if there is any doubt, just replace everything with fresh stock.

[trem]

Hard to say, but I'd DEFINITELY dump the cheap caps on the right. At least the blue ones are good stock (Cornell-Dubilier).

You know, everything works right up until the time it croaks, so if there is any doubt, just replace everything with fresh stock.

Yeah, I agree. I already have them out of the board.
Thanks