potentiometer for preamp

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Yes! They are exact replacements for the MIL RV4 style hot mold carbon pots like the Allen Bradley Type J pots from the '50s.

I was restoring a few UREI LA-3A limiting amplifiers, which used Type J pots, and the originals became intermittent and noisy. I do not expect hot mold pots to be sonically neutral, and because of that, I wanted to restore the unit using hot mold replacement pots. You can get NOS Type J and also Ohmite type AB pots, but for maximum life, I wanted brand new pots that haven't been sitting around for 40 years whose tracks have 'gone weird'. Not sure if that happens, but I didn't want to find out and the new Precision pots are nicely priced, and brand new.

After installing them and rotating them a bit to 'settle them in', they seem to work great - just like a brand new, quiet Type J.

I'd recommend them if you want the noise and voltage coefficient of a hot mold carbon pot - they're well manufactured and attractively priced, and remove the uncertainty of NOS parts. If you want "clean" I would not recommend them, but then again, I did not measure their distortion - they were going into a '70s circuit that is decidedly not clean and authenticity was more important for that device than cleanliness. So, for circuits like this and tube circuits from the '50s, I would recommend them highly.
 
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