Electronics help needed

[DGXSER]

Completely off topic perhaps, but some of you folks seem to know alot of the old electronics stuff.

I have a 1962 Harmony Stratotone electric guitar that belonged to my father. I learned to play on this guitar (no amp was allowed during the learning period to save on ears).

Anyway, I just recently got an amp for it, and it will not play through the amp at all. Here are pics of the electronics involved...







The buzzing quiets considerably when I tap on the TONE control, but the sound never comes through the amp.

Any suggestions or help is appreciated. Primarily I'd like to know what the tone control and volume control devices are, how they work, and what to look for in what may be wrong with them.

[planedick]

Pots

Those are pots, or potentiometers. Also known as variable resitors. There should be a value written on them. Something like 10K or 5K or 1M and a current rating, like 2W. Readily available and cheap.

[rpgoerlich]

Looks to me like your missing a couple wires that would goto the output jack.
Did you have to de-solder them to remove that plate that holds the pickup and pots?

[DAVINCI]

Try wiring the jack leads direct to the pickup an see what you get. That will prove that the pickup is good. Beware, it wil be on full volume! +1 on what planedick wrote, those pots look grimy, looks like it's been stored in a damp location? A bit of the old Radio Shack 'tuner cleaner' may get them working again. Squirt it right into the hole in the back of each pot and work them back and forth a few times.

[hamjam]

Values are 2 x 1 megohm linear (volume), 2 x 330 kilohm linear (tone) and 1 x 220 kilohm logarithmic (*blender"). FROM GOOGLING it

definitely try the cleaner on them you shouldnt have had to remove the wires from the 1/4 " jack
good luck fun guitar

[DGXSER]

Through cleaner and messing with it, I got it working, but still alot of buzz, and volume on guitar and amp have to be almost all the way up to get sound from amp. When I turn it off at the guitar the buzz gets much louder.

I assume the capacitor (I think thats what that is, reads .1 MFD, 150v) is an either it works or not thing. And if the wires were completely shorted somewhere it would not work at all...same for the pickup? Correct? So those pots must still be soaking up alot of juice I guess. Or the jack is work and maybe shorting.

I ordered new pots and a new jack from Amazon. Shipping is as much as the parts. But a heck of alot cheaper than any music store would charge to fix it!

[hamjam]

and if i may suggest ground all the components with a wire I see that the pots are and the switch but you should also ground the PU and the ground from the jack goes beside the one on the pot

[TopCatGr58]

Hey DG,

That brown thing with colored bands looks more like a RESISTOR, but you said it's labelled with capacitor stats...a search for 0.1 Mfd capacitor showed a site with description of GUITAR CAPACITORs, for tone control circuits.

That cylinder cap looks like it might have been filled with electrolytic fluid, they are known to dry out, etc.. I replaced something like 15 caps in the power supply for an old Pro. VCR deck, and it works great now. So I'd suggest replacing that CAP along with the Pots.

See this site
http://www.guitarpartsresource.com/e...capsorange.htm

I also found that caps can be color coded like resistors!
T.C.

[cywelchjr]

+1 on replacing the electrolytic cap. Those are a common failure component and can leave you with a buzzing sound. I can't say for sure, but some of the old electric guitars need a preamp to work with newer transistorized amps (or was that the other way around, frankly I forget, it's probably the other way around actually). But the cap being bad I believe could cause low volume and it likely to be a cheap fix, you can probably pick that up at radio shack.

[DGXSER]

Thanks for all the help!!

I will look at radio shack for the capacitor. May as well do it all while I am in there.

Those pics are actually off the Harmony website, but are exactly the same as my guitar. Only difference is, mine has the jack wired in...



Hard to see in the picture, but the positive (tip of plug contact) goes to the middle connector of the middle / volume pot. The negative or ground part (shaft of plug) goes to the third connector of the volume pot and that connector is bent inward with a glob of solder connecting it to the body of the pot.

The ground or bare conductor part of the pickup wire, also is soldered to the body of that same pot. The positive of the pickup goes to the first connector of the first pot.

[hamjam]

all is good then, new cap time
btw 3 of my amps are from the early 60s all tube 2 are less than 5 years old one tube, none of em care what guitar or bass I play through em. I have a pair of 65 gibson basses a 67 les paul , a 66 casino , and the new stuff a 90 strat a 92 jazz bass , and a Simon and Patrick that's from 2001
just wondering your new amp, is it new transistor or does it have tubes ? and can you play other guitars through it? old tubes can go very fast and the caps in them also dry out
Jim

[DGXSER]

I got a new, very beginner amp....Its a Roland Cube 15. Small Portable has some distortion and gain. Can also play an MP3 through it to play along with a song. Basically alot more stuff than I ever used before. The old tube amps my dad had just had a volume to them. No effects at all.

I learned to play on this guitar back when I was 14-15 yo. My son just turned 14, he seems mildly interested which at this age seems to equate to ecstatic about things, so I want let him learn on it. The action is so light it is easier on the fingers than my acoustics. Besides, Back in Black just does not sound right on an acoustic or without the amp.

Radio shack will get a visit tomorrow. Hopefully they still carry this kind of stuff. Around here they seem to have scaled back to just basic stuff.

[DGXSER]

The shack had the capacitor, and with a few minutes of soldering work it has been replaced. Still seems to be a loose connection or something as the buzz comes and goes and the volume definitely needs to be a bit high. But I have a new jack and new pots coming.

Suffice it to say that I have sore finger tips and a sore left forearm!! Thanks very much for the help!!! What other motorcycle site can you go to and learn how to repair an antique guitar!!

[Larrym]

Sure or Not so Sure???

Are you absolutely sure that the guitar cord itself doesn't have a problem/intermittent connection?

Cord Repair Link

I was the repair tech for a friends band and broken/wonky cords were the #1 problem.

#2 problem was Lowenbrau beer bottles vibrating/migrating from the amp top to the back of the amp where they kept falling/spilling into the electronics...

[DGXSER]

Larry,

I certainly can't rule it out completely. The cord came with the amp (I convinced them to throw it in with the deal). It is one of the cheap ones really, but it is brand new.

I'll take the cord over to the store I bought it from and try it on their equipment and see what happens.