Silverface Champ Cap Job and Replacement Cap Can

[ThermionicScott]

Scott

Was able to date cap can..74, same as amp, so it is most probably the stock can.

Ah, gotcha! Fender used 32uF of input capacitance in the 5F2A Princeton, so we know they didn't have a problem with it then.

- Scott

[Newguy]

Got this info from another forum and thought it may help some one here:

On the side of the Mallory can cap, there will be an EIA code that will tell you the date of manufacture of the cap (from which you can deduce the approximate assembly date). The code will read "235-YYWWLL 85 C) where 235 is Mallory's EIA code, YY is the two-digit year code, WW is the week of that year, LL is a two-letter code that means something known only to Mallory and 85 C is the temperature rating (Celsius). So you can tell just how old the cap is.

[Newguy]

How big of a soldering gun would you guys recommend to replace this cap? What tip/what wattage?

Thanks

[Tom Phillips]

I use a Weller W100P with the largest 800 Degree tip they make for it.
I have much larger soldering irons too but they are more difficult use because of the physical size.
The W199P was found at OSH. I hear they are sold in hobby stores too. (Used for stained glass work)
Tom

[sgunn]

everyone of those i've seen came with a 3 prong plug wired just like that, neutral to switch. if it sounds good to your tastes why do you want to mess with it? besides moving the hot to switch running heater wires instead of having one leg on ground is all these need. with original speakers they sound great.

[Newguy]

sgunn

Most say best to replace the electrolytic caps every 20 years or so.

[sgunn]

if they need replaced you'll know it,it's not a gigging amp so it probably won't surprise you in the middle of a show.

[Newguy]

if they need replaced you'll know it,it's not a gigging amp so it probably won't surprise you in the middle of a show.

And how will I know it?

[sgunn]

it'll hum maybe motorboat or sound like waves from the ac not being filtered.if you're just looking for something to do go for it they don't come any easier than champs. you might want to use a dremel to cut the solder it can take a lot of heat.

[GibbyLover]

I'll chime in with another question.
I have a '73 Vibro Champ. It's 100% original. It works good, no hum to speak of,but when I turn the Vibrato on, the pot scratches a little (already tried contact cleaner) and with the speed of the vibrato there is some kind of popping / noise that's not there with the vibrato off.
I guess it needs new caps in the vibrato section, but which ones to replace and with what?

[Jazz P Bass]

Here is the schematic.

The Vibrato circuit is on the lower left in it's entirety.
If the .02 plate coupling capacitor goes leaky you will find dc voltage on the speed control side of it.
Check that before wholesale recapping the circuit.

champ_vibro_aa764.zip

[GibbyLover]

Thanks, I can't open the schedule, but I'm sure you mean one of the 2 orange, round caps?


Do I just search a cap 0.02mfd/600VDC, any other specifications to look for?

[dstrat]

try new tube if you haven't already, JPB is talking about the blue .022/600 next to the two orange .01 s.

wow 7 year old thread!.

[Jazz P Bass]

Thanks, I can't open the schedule

I reloaded the file as a zip.
It should open fine.

[Tom Phillips]

Hi GibbyLover,
The photo in your post #27 shows that your '73 Vibro Champ is in original stock condition. For the benefit of historical records for the forum would you mind posting some additional photos including some full view gut shots of the chassis?
TIA,
Tom