So when I inherited my parents record player I took the reciever that came along with it. It's from the 70's or early 80's and was probably top of the line in its time. The only problem with it is that the volume knob rarely cooperates.

When I try to listen to something I have to play with the volume knob to get it to give me a consistent sound. I don't mean I have to turn it up and down. I have to grab the thing and sort of jiggle it until it starts to play through the speakers. Sometimes it comes out on just the right side, sometimes just the left. Sometimes it'll take me 10 minutes just to get it to give me a steady sound, and even then I'm pretty much stuck with whatever volume I can get a sound out of, because if I turn the knob at all I'll have to start all over again.

The story my parents gave me is that my little brother used to mess with it when he was real little until it started acting like this, and they just gave up on it.

I took it apart yesterday to see if there was something obviously wrong with it, like a disconnected wire, or a cold joint.



The volume pot (in the top picture) is the larger of the two. I tried aggitating the wires while it was playing to see if I could isolate the problem. I didn't get any definitive conclusion out of it, but the red and white wires at the top of the picture were the only ones that effected it when I moved them. Also, if I grabbed the volume knob, and the back of the volume pot and put a little pressure on it with my hand it would sound perfect. Of course, a few seconds after I let go the sound would go bad again.

I don't know how many of you have experience with this type of stuff, but any theories or suggestions anyone would care to throw at me would be appreciated.

Not that I'm a contract engineer for a radio station or anything... I'm guessing that there is something wrong with the insides of your pot. Back then they used a piece of metal that was lengthened to make the potential difference higher/lower. They also used a lot of grease in there.

here is what I would do:
borrow a voltmeter and a soldering gun.
Disconnect the wire caps and put the volt-meter on either side. see if you are getting a constant difference across the pot or if it mimics the volume issue you have.

it also looks like the volume knob has 2 jobs? is this one of this dealies that if you push it in, it does something else?

the_reverend said:

Nope, standard knob. Goes left, goes right.

wait wait wait wait wait... it goes left AND right? now I know you are talking out your ass.

it just can't go up or down or back in time

i have one like that ... used to plug my guitar into it and rock out.

I guess it's possible that the wires aren't control-lines, they are actually just R and L. If you don't get a constant signal through with the multimeter, you could just connect them straight across.. but then you would be like man-o-war and playing always at 11

I would replace the potentiomenter with one of the same resistance...

Although it does look like a push/pull like aaron suggested.

That exrtra chamber could be an imp bay?

things wierd looking either way.

most mom and pop electronic repair shops only charge about 5 dollars per solder joint, and that potentiometer can probably be replaced for less then ten bucks... so it might be worth it to take it to a shop.

I would try and fix it myself if I were you, but I have no idea why that pot looks the way it does.

This should be a fun trip to Radio Shack.

you need a good radio shack. most radio shacks don't carry geekstuff anymore.

Any place besides Radio Shack that might have them?

Hobby stores.

ask an old electronics guru what kindof pot it is.

if it were me, I would first borrow a multi-meter from your dad or some one. dads always seem to have them. Also, borrow a soldering iron from him as he will have that too. possible left over from 30 years ago when his parents gave him their old receiver and he had to fix it. turned out it was one of the knobs that was bad.

Test to voltage drop across the pot. Then go to look around the streets of brockton for a stereo that someone kicked to the curb since welfare and multi-child support gifted them a new surround sound system, and rip the knobs off that.

plus 1

the_reverend said:

I actually own a soldering iron. I fairly recently fixed my girlfriend's Mp3 player, and my guitar input with it.

I'll have to ask about that voltage meter. I don't see it happening though.

http://www.pctoys.com/840556052203.html

you would need something like that.

here, $8. VERY useful to have around.
http://www.case-mod.com/digital-multimeter-p-959.html

if the pot jiggle fixes it just get a new pot at radio shack for like a dollar and stick it in. save yerself the trouble shoot. i wouldn't bother with the multimeter too big of a hassle for a small problem. probably is loose and grounding something that shouldn't be grounded.

digital multimeter are 3$ at autozone. then u have to figure out how they work.

radio shack will have pots im like 95% sure.

most ratshacks don't have parts anymore. more cellphones.

you need a multimeter with voltage and resistence.

xmikex said:

http://www.theonion.com/content/news/even_ceo_cant_figure_out_how

sxealex said:

They MIGHT has standars 500,50, or 250 k pots, but there's no way they would carry a specialty pot like that.

There's a radio shack in amrshfield(I think) that has all kinds of components and shit.

tl; dr

Just delete system32, you should be all set.

So this is the volume pot I took out of the stereo:


And here's what I bought at radio shack


Obviously the old one is bigger than the new one. But they're the same resistance, and have the same connections. Are newer pots just built smaller than the older ones? I've got to plead ignorance on this one. Is it worth trying or should I just get my $3 back, and head down to You Do It Electronics?

I would say it's worth a try if the resistance is the same.
yes, things get smaller as they get better.

the_reverend said:

you keep telling yourself that.

*zing.

that's what your mom told me.

oh man fixing stuff is awesome. Once you get this working, everytime you use it you'll just be like "yeah, i did that" and get a warm and fuzzy feeling all over.

That new pot should be fine. Funky little bigger that old one is!

Josh, you obviously didn't read the thread. way to come in late in the game kid.

the_reverend said:


yep... read it.... edited my post haha.

DeRtOxIa said:

haha yeah, it'll be an electrical current running through me because I wired it wrong or something.

You probably should have picked up a couple replacement fuses as well.

i bet that if he marked the wires hell get it on the first try.

sxealex nli said:

way ahead of you.

Niccolai said:

guh?

just ignore him, we all do

Tried the new pot, got it on the first try.

And what's the first song I hear on the radio when I turn it on to test it?
Judas Priest, You've got another thing coming haha. fuck yeah.

thanks to all for the help.