upgrade speaker on superstar

[Colonel Kernel]

Hello again! So, as the other thread stated, I just recently purchased a superstar. The person that I got this amp from, for some reason, changed the speaker in the 80s to a radio shack 15" realistic... So, I'm changing it. I just received my wgs american vintage, but I'm noticing that there's a red wire soldered to the negative and a green wire soldered to the positive side; is this correct?!? My understanding is red is positive... When I played it upon purchase, it was working just fine.....

 

[Default]

It doesn't make a difference in this case, but does it have a speaker out jack that the speaker plugs into? Whichever wire goes to the tip is the positive. Why was the speaker changed? Probably because the previous owner robbed the 15" JBL out of it for some reason.

 

[Colonel Kernel]

Not sure how to post a picture. I popped open the jack and the green is connected to the middle of the post and the red to the side. The guy that owned it is an alcoholic with some severe ADD issues, I think it's legit ADD. Not sure why he changed it and I didn't want to get into that conversation with him (one of those people that thinks he's knows everything).

 

[Colonel Kernel]

How do I post a picture?

 

[Colonel Kernel]

Sorry, just read it in FAQs... Gonna try to put one in here.

 

[Default]

The green is the positive. It's a single speaker amp, so the polarity doesn't matter. If it had a couple of speakers in parallel (like a Thunderbass or a Maverick), then it would make a difference, as the speakers would cancel each other out to a certain extent, if the positives are not connected the same.

 

[Colonel Kernel]

Thanks again for your insight and hasty reply. Sometimes I feel as though I've forgotten more than I'll ever know. I've gone years without playing guitar and am now picking it up again. I live in south Texas and several years ago, a hurricane destroyed most of all of my equipment, so I just kinda stopped. Started fishing more instead of playing guitar... Sometime recently, something in me just snapped and now I'm starting to replace some gear and fix some of my guitars that weathered the storm. Anyways, thanks!

 

[Default]

This is the place for enablers, so if you are looking for something in particular, let us know! Also, think about stopping by Austin the last weekend of March. A bunch of us are getting together and touring the Collings guitar factory, among other activities.

Shenanigans will ensure.

 

[Colonel Kernel]

Man, that sounds good and I need a break from work, but I doubt I'll be able to make it out that way.
I do have one more question regarding this amp though; what is the knob on the back for? It says hum one one side, balance on the other. It crackles when I mess with it...

 

[Default]

It's a hum balance. It's a 250 ohm pot to ground that replaces the 2@100 ohm resistors that you find in a Fender's tube heater wiring. You crank it up with nothing plugged in and adjust it to where you get the least amount of hum. It crackles because it hasn't been touched in a long time. Just sweep it back and forth about ten times and that should clean the innards. ;-)

 

[Colonel Kernel]

Yeah, that thing won't stop popping and crackling when I turn it. I've swept it back and forth to no avail. The only thing I hate, is its riveted to the chassis (or box). Any 'ol 250k pot will work, huh?

 

[Colonel Kernel]

Or some kinda spray cleaner or lube sprayed in from the backside?

 

[Default]

Spray cleaner would work fine, but it's a 250 ohm pot, not a 250,000 ohm pot.

 

[Colonel Kernel]

I do apoplgize if I'm being a pest. I'm having trouble locating a 250 pot online. Do you have a link you could share? Also, what harm would it cause if I was to use something different, say a 250k or 100 ohm?

 

[Default]

I would just get a can of electronics cleaner from radioshack and spray it out first. You really should have a can of electronics cleaner anyway, for spraying out dirty controls on guitars. 250K is way too high to work. That's intended for tone controls. Here's a link to the Hoffman amp board where Doug talks about the heater system on Fenders. The principles are the same.

 

[Colonel Kernel]

Well, tried the electronics cleaner, seems worse. While I had the power supply unbolted, I plugged it in, turned her on with it still on stand by and waited for the tubes to heat up. Once heated I started turning the pot. Its arching out on the wire after the small blue capacitor, so I'm going to throw in the towel! My knowledge on this subject is too limited. I'm guessing that little capacitor is burned and allowing too much past it? But I'm afraid something might burn up if I keep messing around; just gonna take her in to a tech. I certainly appreciate all the advice you've given me. I was honestly hoping this thing wouldn't turn into a project... Thanks again for the info, you're a very nice person. I wish I could meet some of the people in Austin.

 

[Default]

Post a pic of the blue capacitor if you would. I'm confused. There should be two wires from the tube heater circuit(blue and white on mine) going to the outer lugs on the hum balance pot. The inner lug is the wiper and has a wire to ground. There should be another wire running from a big can capacitor that injects dc from the power supply to reduce heater noise. There are two screwdriver adjustments on top of the chassis with the 12dw7 and the two 6l6's, but those are for the bias.

 

[Default]

I really need a photo as clear as you can make it.

 

[Colonel Kernel]

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received_m_mid_1392869908879_5de64e54fbc7ad1223_0.jpeg

 

[Colonel Kernel]