Help me to find a new potentiometer for broken audio mixer EQ pot.

...and how to do so...
Rodhex
KVRer
24 posts since 19 Oct, 2014

Post Thu Aug 30, 2018 6:29 pm

Hello guys.
I have a mixer with some eq potentiometers broken (their shaft is plastic), i want to replace them for new ones but I don't understand their part number yet, i mean i know it is a 30MM (shaft) with Center Detent potentiometer but what about the rest specs/code? :?: . This is a screenshot of its service manual. Thanks.
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PS. I'm not sure if this post is ok in this forum section.

knockman
KVRAF
1830 posts since 21 Feb, 2004 from somewhere! anywhere!

Re: Help me to find a new potentiometer for broken audio mixer EQ pot.

Post Fri Aug 31, 2018 3:11 pm

That service manual scan looks like it could be a Phonic mixer? If so, the part numbers may not mean much other than to Phonic themselves?

The only thing I can add to what you've already stated here is that they appear to be 50kΩ linear taper pots based on the specification "50KB".

Have you removed the damaged ones? If it's just the shaft that's broken and the actual pot still functions, perhaps checking them with a multi-meter could confirm the spec - as well as checking the physical dimensions. Are they panel mount or PCB mounted? Either way, you could probably source identically spec'd replacements from various sources.

Rodhex
KVRer
24 posts since 19 Oct, 2014

Re: Help me to find a potentiometer...

Post Mon Sep 03, 2018 3:52 pm

Yes knockman, it's a Phonic. The 2 eq pots (MID and Low) still work, i put some audio in the channel, then i used a tweezer to rotate the 2 eqs and the sound is ok.
I opened the mixer and wow man, it's not gonna be easy to take apart all that pcbs to be able to measure adequately all the parts of those damaged pots. Anyway, I did took some physical dimensions of the pots and it wasn't easy at all. See some pics of the mixer (marked in orange the 2 damaged pots). Thank you for your reply Knockman.
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Potentiometers croquis.

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Side view.

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Wow, 2 pcbs, one over the other.

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These 2 pcbs are connected each other with a lot of soldered cables (red area).

PS: i have the broken parts and the caps but i wanna try to replace the pots instead of repair their shafts.

Rodhex
KVRer
24 posts since 19 Oct, 2014

Re: Taper Linear or Audio?

Post Fri Sep 14, 2018 5:31 pm

knockman wrote: The only thing I can add to what you've already stated here is that they appear to be 50kΩ linear taper pots based on the specification "50KB". .....you could probably source identically spec'd replacements from various sources.
I think i'll buy this but its height is 25MM and I'm not sure yet if its taper should be Audio or Linear, the one i found is taper Audio. The 2 broken encoders to be replaced (i hope) are for EQ Gain, ie when they are at 12 o'clock there's no tone variance, when full right (5 o'clock) there's a 15db gain increment and viceversa (-15db when 7 oclock). Thanks knockman.
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