I'm working on a marshall head for one of the local music stores here. The volume pot is flaky, needing replacement. According to the schem, it's a 5K Linear pot, which is bad enough, but the pot (factory original) is a 5k reverse-log pot.
I've replaced lots of linear volume pots in Fender Hot-rod/blues/deluxe/deville/seville/escalade/etc w/ real audio pots, but this is the first time that I've ever seen a reverse log pot in a volume control, gain controls on distortion+ type circuits notwithstanding.
Anyone have any experience w/ these? I threw in a 10k linear pot for testing and it seems to work fine. The original pot wouldn't maintain a signal long enough for me to tell if the curve was as nasty sounding as theory would suggest.
That, and I hate PCB mounted pots. And tube sockets. Everything I've repaired in the last 4 months has been a damaged PCB mounted pot or tube socket. Drives me nuts. I charge extra for those.
Matt
Marshall MG100HDFX -- Reverse log volume pot?
Moderators: pompeiisneaks, Colossal
Re: Marshall MG100HDFX -- Reverse log volume pot?
Well, if what you put in seems to work fine, I suggest there are two apparent courses of action.
1) You close it up and tell them it's fixed. The problem with this is that it is not the whole truth and you have modified and departed from the original design. Later, when you are found out, you run the risk of having your credibility questioned. I wouldn't recommend doing this.
2) What I would do is close it up, disclose what you've done, and suggest it is better than new. There will be an additional bench charge when the rest of the repair is done if the customer wants it set back to the way it came from the factory, tell them you'll need to order the part and you'll let them know when or if it ever comes in.
#2 is honest and is a whole lot less risky.
1) You close it up and tell them it's fixed. The problem with this is that it is not the whole truth and you have modified and departed from the original design. Later, when you are found out, you run the risk of having your credibility questioned. I wouldn't recommend doing this.
2) What I would do is close it up, disclose what you've done, and suggest it is better than new. There will be an additional bench charge when the rest of the repair is done if the customer wants it set back to the way it came from the factory, tell them you'll need to order the part and you'll let them know when or if it ever comes in.
#2 is honest and is a whole lot less risky.
Re: Marshall MG100HDFX -- Reverse log volume pot?
you can order parts through Korg the USA distributor of marshall.
My Daughter Build Stone Henge
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Dingleberry
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Re: Marshall MG100HDFX -- Reverse log volume pot?
Alpha makes 5K rev. log pots. Both PCB mounted and with normal soldering lugs. I think you should find Alpha pot dealer anywhere in the world.
-T
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