Calling all audio engineers...

[Chaotic42]

We're having a problem here at work. We're 99.999% done setting up our second production room. We have 2 nagging problems.

The first is that all of the pots on our board (it's an old McMartin with rotary pots) are dirty. Any time we adjust the volume, we get horrible static and noise.

The second is that everything recorded in there has a low hum behind it. My boss says it's "good enough" but it isn't. I realize that we *should* get a new board, but I don't see that happening anytime soon.

Can anyone give any advice on how to clean up the board? The hum has to be the board, because everything else (MD, Computers, CD) is new.

Thanks in advance,
Chris

Edit: Hey, this is my 2001st post. Cool.

 

[blahblah99]

Old amps with pot. volume control tend to make that static noise.. you can temporarily fix that by turning the knob back and forth a few quick times. Its better to pull out that old pot, measure the resistance, and pop in a new one.

As for the hum, thats coming from your AC line and the power supply isn't filtering it out correctly or the reservoir capacitors are not big enough.

 

[Colt45]

for the pots.. either replace them, or clean them. (dissasembly required either way ).

I hear this de-oxit stuff cleans pots pretty good..


as far as the hum.. is it 60hz? might be crappy filtering on the power supply for something.. leaky filter caps perhaps.. maybe replace them.

(has no idea on how the board is powered)

thats all I can think of for now.


how old is this thing btw? what other eqipment you have?

edit: ARGH! blahblah beat me

 

[Chaotic42]

Here's an mp3

Please be gentle on the server.

The board is circa 1970. It's connected into an old power strip with the other equipment. It's about 10 feet from our AM transmitter (in another room).

Yes, I know this makes no sense

 

[thomsbrain]

Well, I hear a crapload of hiss, but only a little hum... You should be running it on a power conditioner anyway, which might help with the hum. But damn, that's a noisy board to be putting out that much hiss on digital recordings. I think it maybe it needs to "accidentally" get broken, if you follow my drift.

 

[Chaotic42]

Originally posted by: thomsbrain
Well, I hear a crapload of hiss, but only a little hum... You should be running it on a power conditioner anyway, which might help with the hum. But damn, that's a noisy board to be putting out that much hiss on digital recordings. I think it maybe it needs to "accidentally" get broken, if you follow my drift.

Yeah, the hiss is worse now than it was.

I'm sure it could be accidentally broken, but it knows that it won't be replaced ever and that it's poor users would have to fight to the death for time in PR1

 

[Chaotic42]

Bump

 

[RayH]

If the pots are exposed or if they have cases with holes you can try spraying tuner cleaner on them if they haven't been worn too much. Can be found at Radio Shack.

 

[Chaotic42]

We got it fixed. It was the transformer.
Thanks everyone.q