JT30-RH volume control non-linear behavior
I experience a strange behavior of my Astatic JT30-RH "Roadhouse" microphone's volume control. When the volume control knob is being turned, volume produced by the microphone changes in a non-linear manner. It seem that it has only 3 volume levels. If the knob's position is between 0 and 2, no sound is produced, if it's anywhere between 2 and 9, the sound is at 50% of available volume, and if it's between 9 and 10, the sound is at the loudest level.
Is this normal?
Hi Greg,
Unfortunately, warranty on the microphone has expired. Do you know where I could find a better quality potentiometer to replace the faulty one? It should be 5M Ohm, as far as I know.
Thank you,
Mikhail
That pot is indeed a 5M pot and is a Chinese copy of the pot Astatic used in the JT30VC (and Hohner used in the BluesBlaster.) I'm afraid you will not find it at electronics supply specialists like Mouser, DigiKey, or Jameco.
I think your best bet is to get in touch with HOhner and see if you can order it as a repair part from them.
/Greg
I just got a reply from Hohner for my inquiry about ordering a replacement pot. They said they don't carry this part and suggested to visit guitar parts retailers such as All Parts or Stewart McDonald. I doubt they have the pot. I guess I'll just have to live with what I have...
How do you like that. A company who can't even provide service parts for their own produicts. I think that's inexcusable.
The pot CAN be replaced, but there are a bunch of issues. The internal surface is not parallel with the surface the nut would sit on. When the original pot is used it is located by the long hole and shaft. But a replacement pot will have a shorter shaft of smaller diameter so it must be retained by its nut squeesing it against the inner surface - and it won't work because they're not parallel. Also - 5M pots are very hard to come by. I have done extensive mods to these shells but usually to ccaompany an upgrade to a better element - move the screw-on connector to the rear where it was on a JT30 and move the VC to the front hole where it fits better. It is a fair bit of work - costs more than the mic did.
If you want a better mic - I would recommend looknig around for a genuine JT30 or older Shure bullet shell as the foundation for the project. I have a small inventory of shells like that - but my primary business is my wood mics and Ultimate mics.
Hi, Kaz
No, that is not normal - but not entirely surprising. Hohner has used extremely cheap chinese components to make that mic. I hate to sound critical - I thinn the mic sounds very good for the money, and that's what matters - but it is a fact. Yours has a faulty potentiomer. I would take it back to the store where you bought it and ask them to repair or exchange it.
/Greg