Scratchy vol pots Yamaha 1005.

Dag Wolf · From: Bergen, Norway

I have two Yamaha 1005 and both input A&B has scratchy pots. Each have seperat vol pot. All other pots on each unit are fine.
I have tried to spray them - no help or difference.
I suspect it might be a component that has a fail.
These units are over 40 years old but sound so good.

Any help are appriated.

Thanks,
Dag

Jerry Overstreet · From: Louisville Ky

Dag, is that the old 80s vintage analog delay unit? I know that there were several brands of the same units. And you're right, they do sound great.

I have the Electra EP250 analog reverb/delay that's almost the same unit with the added reverb circuit if yours is the unit I think it is.

I does seem strange that it's just the vol. pots and an issue on both of your units. I don't know enough to suspect anything other than the pots, but.....

I have mine apart so I took a look and those pots look really easy to change once you have the case off should you decide that may be your problem.

They are 16mm size 3 tab solder lug right in plain sight. Very easy to get to on mine. No need to pull out any boards.

You just need to know the value. I can't see the value or type numbers, but it would be easy enough to pull one and check while my unit is apart.

Lemme know if I can be of any help. JO.

Here's a link to some of the info, there's more from this site but you have to log in. https://manualmachine.com/yamaha/e1005/8533041-schematic/

Dag Wolf · From: Bergen, Norway

Jerry, yes it’s a delay and Modulation (chorus/flanger) unit. I don ‘t think it’s the vol pots itself. I suspect a component related to the them.
When pot’s are failing I always har gotten some kind of change og the scratchy noise. Now, no change.

Dag

Jerry Overstreet · From: Louisville Ky

Sounds like you need to see a qualified techinician to diagnose your problem. I believe there's a schematic, which they will need, in the link I sent you. You will have to log on to their site to get it.

You're fortunate if that is still available. Some of that era of electronics information is no longer.

Good luck.

Dag Wolf · From: Bergen, Norway

Thanks Jerry👍😃

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