66 Vibro Champ .... Cap Job

[Totally bored]

I'm picking up a 66 Vibro Champ tonite. Very excited and I have been wanting one for quite a while . She will need a cap Job and I have a few questions as I have done this on a Few DR's and PR's but never a VC.

1. Where the heck can I get a Cap Can for this ?

I google and get nothing.



2. Also, where is the Bias cap on this thing ?

I may change out the ( 4 ) 25/25 caps just because but I realize that normally the Can and the Bias cap are the ones that must be done.

Here is a couple schematics to help me/you Identify stuff







This is not my amp but the Chasis I imagine will look the same ( I'm told by the current owner and friend of mine) and the pic may help you/me Identify the Bias Cap.

[ziess]

Weber do cap cans;

https://taweber.powweb.com/store/capord.htm

Right down the bottom of the page. Select an appropriate one based on the schem.

The bias cap (well, the cathode bypass cap) is the one that's connected to pin eight of the power tube (V3) and paralleled with the 470-1W resistor to ground.
*All* electrolytics should be changed if they're original. When I got my Twin the caps had been changed by Hoffman in 1996 but I still replaced them. Cheap insurance.

BTW, if yours has the original ground switch setup with the death cap you should keep the cap as a spare. Those blue molded caps are really great sounding.

Tommy.

[ziess]

Oh, no ground switch on a Champ. Nevermind, hold onto that cap if it's there though.

[Totally bored]

word

[Totally bored]

Okay so I went here http://www.vibroworld.com/parts/tech15.html


If you scroll down in the "Polarized Electrolytics with Axial Leads" section there is a listing for :

25 mfd @ 25vdc
Sprague Atom TVA1205
Cathode Bypass Circuits .525 x .270-inches US$3.15

I'm quessing I need 4 of them and that would cover the Bias cap and the other 3 electrolytics ?




And If You scroll down the " CUSTOM MULT-SECTION CAPACITORS" there is a listing:

20/20/20 mfd @ 475vdc

3-section chrome Can, Twist-Prong FP type. Fits Fender Champ, Supro, Gibson and other small combo amps. Dim: 2.50 x 1.50-inches US$29.50



I'm quessing thats the Can and how did I do people ?

and

I'm hoping I don't need a special adapter to mount that can whatta ya think ?

[Don]

I bought a replacement can cap for my Princeton Reverb from Antique Electronics. It was all pretty straightforward.

[Gris]

Antique is the place (or Weber). VibroWorld is mucho exclusivo amigo - :-O

[Totally bored]

I can't figure out how to get the "Can" @ Antigue ? Theres No good listing for the Can.


Whats wrong with VibroWorld ?

[Don]

Try this p/n-
C-EC20X3-525

[Gris]

Whats wrong with VibroWorld ?

$$$

[Mandopicker]

Look at the schematic carefully...You actually need 3 x 25uf@25v and 1 10uf x 25 volts. I'd even suggest using 2 x 25uf @25v, 1 x 10uf@25v (connected to pin 8 v1), and 1 x 25uf@50v (for the bias cap)

Of course you could use all 25uf@25volts, even in place of the 10uf@25v, but you'll want to consider how it effects the tone. The 25uf@50 volts is a good idea when in the bias cap position.

Just my 2 cents...

Have fun bringing it back to life/spec.

[Gris]

BTW, it's way cheaper to sub in individual caps than it is buy a can...

[Totally bored]

Look at the schematic carefully...You actually need 3 x 25uf@25v and 1 10uf x 25 volts. I'd even suggest using 2 x 25uf @25v, 1 x 10uf@25v (connected to pin 8 v1), and 1 x 25uf@50v (for the bias cap)

Of course you could use all 25uf@25volts, even in place of the 10uf@25v, but you'll want to consider how it effects the tone. The 25uf@50 volts is a good idea when in the bias cap position.

Just my 2 cents...

Have fun bringing it back to life/spec.

Wow, I see the 10/25 uf now that you point that out and I now remember reading somewhere about the 25/50 uf for the Bias cap. This is why I started this thread so I wouldn't order to the wrong parts. Thanks , I appreciate your help.

[steve25]

While you are working on the amp you should re-wire the heater string so that one grounded leg off the heater winding is feeding the tubes and pilot lamp like a regular fender heater set up.
With this mod you will also have to add a 100 ohm 1 watt resistor to ground oof of each leg of the heater winding, this will make for a much lower hum level from the amp and will also let you bias the heater string up with some dc voltage if you lile for even less noise, and can always be put back to stock ( no holes drilled, just things soldered) to retain the amps selling value!

[Totally bored]

So I order'd the parts from Jon @ Tonecraft http://www.tonecraftamprepair.com/html/jon.html

Great guy and very helpful, parts should be here soon.

Can't wait to fire this little guy up. She looks quite comfy in my studio.

[Totally bored]

ok so now I know why I got this amp at good price, it needs work.

The guy I bought it off said that the Bias cap got real hot and smoked . So I replaced the Bias cap with a 22 uf 100 volt and I'm reading 55 volts on pin 8 on the 6v6 that is supposed to read 21 volts. The 470 ohm resister reads 470 ohms so its not that. Everything else appears fine although I'm still diagnosing the amp, I'm a bit slow at this. I only do these things every once in a while so... arghhh !!!!!!

On the 5Y3 pin 4 and 6 read 330 volts so thats kinda ok. Schematic says 315 volts.

On 6v6 pin 3 (Blue wire) reads 315 pin 4 reads 300 volts and pin 8 that goes to the Bias cap reads 55 volts.

THE Can reads 300 volts ...315 volts and 330 volts so those are all down about 20 volts.



Argh!!!!!!!!!!! I'll keep tinkering

[music-n-motorcycle]

BTW, it's way cheaper to sub in individual caps than it is buy a can...

That's what I do because it is way cheaper.

[Totally bored]

All fixed and repaired. Sounds absolutely killer.