Silverface Champ Cap Job and Replacement Cap Can

[Newguy]

Can someone please supply me a link to a replacement on the Silverface Champ amp cap can (I think I have orig it says Mallary (sp).

Mojotone has BF Vibro-Champ cap kit, but I do not see the cap can:

Blackface Vibro Champ Capacitor Kit

This is supposed to be replaced when replacing the caps correct?

I am researching parts now, as I have another amp I am going to do first. I have had chassis out and I notice some bubbles on a few of the smaller caps. Amp sounds great though, and pretty quiet.

Thanks

[Newguy]

Talked with mojotone, they said this is the part:

Mojo Capacitors » JJ/Tesla 40uF+20uF+20uF+20uF @ 500V (Clamp 3166110)

Specs say 1 5/8" diameter

Mine looks to be about 1 3/8" diameter??

There must be a correct replacement part out there? Any comments/help?

[ThermionicScott]

I haven't used the JJ one, but I know this one is correct: https://secure.cedist.com/scripts/fo...m=C-EC20X4-475

If you want to reduce hum and/or bring down the B+ voltage, there is a mod to use the extra 20uF filter and create an extra Pi filter "in front" of the OT. I can't recommend it highly enough. Here's a '66 Champ on which i performed the mod:



Note: This one had an extremely high B+ -- you probably wouldn't need 2.2K to bring yours down to 360V.

- Scott

[Newguy]

I haven't used the JJ one, but I know this one is correct: https://secure.cedist.com/scripts/fo...m=C-EC20X4-475

If you want to reduce hum and/or bring down the B+ voltage, there is a mod to use the extra 20uF filter and create an extra Pi filter "in front" of the OT. I can't recommend it highly enough. Here's a '66 Champ on which i performed the mod:



Note: This one had an extremely high B+ -- you probably wouldn't need 2.2K to bring yours down to 360V.

- Scott

Thanks Scott..I am not sure, but maybe you clicked the wrong one, my Champ (from memory) is 40/20/20

Here is one I found, looks to be exact same maker/vender, but 40/20/20 and rated at 525vdc (higher rated is OK...I think, correct me if I am wrong). That same place has 40/20/20/20 so it could be used for the mod you talk about (correct me if I am wrong). I am new at this so most times I am just asking:

Amplifiedparts.com: CE Manufacturing 40/20/20/20uF 525VDC Multi Section Can Capacitor

Not cheap though at $35. I saw forum where guys leave the cap can there (but disconnected), and just use single caps in chassis. I think I would rather spend the extra bucks and have it stock though.

My Champ is quiet. I am not replacing because of hum, just researching all parts needed because of age of amp and all the talk in forums to replace electrolytic's in amps over like 15 years old. However, I will look into this mod.

In pic you posted, what is the black epoxy looking stuff around the cap can base? Was that needed to keep from rattle or what? (never mind, it is just glare from pic and what I thought was black looks to be just solder). lol..where are my glasses?

[ThermionicScott]

The original was 20/20/20@450V. Most folks who use the 4x20@475V cans just leave one section disconnected.

It's good that you're thinking about replacing your electrolytics! A big soldering gun helps free up those tabs on the can.

- Scott

[Newguy]

The original was 20/20/20@450V. Most folks who use the 4x20@475V cans just leave one section disconnected.

It's good that you're thinking about replacing your electrolytics! A big soldering gun helps free up those tabs on the can.

- Scott

Scott, are you sure? The can is Mallory (forgot to check spelling), it is a 40/20/20 @ 450v?

If you are sure, someone has already replaced the can? Wish I knew more history on the amp. I had chassis out, things looked to be pretty stock (meaning no one has hacked it up), except someone put a Peavey Blue Marvel speaker in it. I was not happy about the speaker...until I played it for awhile, the thing sounds real real good. I am very happy with the sound of the amp.

[riz]

My '64 Vibro-champ had 40/20/20 stock. BTW the cap cans in old champs seem to last a long time... Mine wasn't bad, yet, but I replaced it with a CE manufacturing model. Direct fit. I think I used a 20/20/20/20 and tied two together to make 40. The JJ will require enlarging the hole in the chassis.

[Chuck H]

If the new cap will fit properly and the old cap can is a 40/20/20 but the new cap is a 20/20/20/20 just parallel two of the 20 sections on the new can together for the first filter.

[Newguy]

Appears the cap can has been replaced (see attached pics), and two globs of solder not being uses by base of cap can.

Also, cap can is 40/20/20, and stock probably should have been 20/20/20.

What is the advantage of the 40/20/20 over the 20/20/20?

By looking at pics, can you guys tell me any thing (IE stock wiring, condition of other caps/resisters and such?

Thank You

[Newguy]

Side not, the two globs of solder by the cap can base does not look to be connected, probably what is left of the orig that was soldered in.

Amp sounds good, little noise, but should I consider putting a little solder to solder the cap can in for a more solid ground.

Any suggestions?

[Newguy]

Another question/help needed

I have been able to get amp covers with the Fender logo on it for all my Fender amps, at a pretty cheap price I might add. I have been searching for a while for an amp cover with the Fender logo for the Fender Champ, but all covers seem to have no logo?

Any one see a champ cover with Fender logo?

Thanks

[Tom Phillips]

Appears the cap can has been replaced (see attached pics), and two globs of solder not being uses by base of cap can.

The filter can installation looks original to me. It is not uncommon to find component values in these old Fender amps that do not exactly match the published service information

What is the advantage of the 40/20/20 over the 20/20/20?

More filtering (40µF vs. 20µF) on the first filter stage doesn’t hurt.

By looking at pics, can you guys tell me any thing (IE stock wiring, condition of other caps/resisters and such?

The power cord has been upgraded to a 3 wire grounded unit. However the ON/OFF switch is wired in the neutral lead instead of the hot. This is a common “upgrade” mistake. Both the fuse and the switch should be on the hot side. The amp works just fine this way but the wiring is not to code and there will still be 120V present in more places inside the chassis with the switch OFF.
It appears that the power tube cathode cap has been changed since the amp was new.
The rest of the parts look original.


Regards,
Tom

[Chuck H]

Nah, Two of those tabs is plenty of contact. One reason to stick with the stock 20uf value for the first filter is the rectifier tube has a max uf rating of 20uf. This is to keep current spikes within the rectifiers capability. IMHE 40uf is safe for a 5y3 and I wouldn't worry about it. Other than this consideration the higher uf value only has advantages for other circuit criteria. If the amp isn't humming or "ghosting" and the can "looks" to be in good shape it's probably OK right now. This is assuming it HAS been replaced at some unknown time. The only way to be sure with an amp that age is with a new filter.

[ThermionicScott]

+1 on what Tom and Chuck said. It's not outside the realm of possibility for CBS/Fender to ship a Champ with 40uF for the first filter stage, it's just not on any of the schematics I've seen.

- Scott

[Newguy]

Scott

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