Anyone know where to get some pot?

[gain]

i am repairing this receiver i got at a yard sale some time ago. got both channels on the amp board working good and sounding very nice (one was toast), but the volume pot turned out to be scratchy (surprise, surprise). i pulled it out and saw something strange, for me at least.

this is a typical dual ganged 100K stereo pot, but it has TWO loudness taps PER CHANNEL (4 total) on the bottom (see attached). in other words, measuring on one channel only with the pot removed, working clockwise, i have ~40K between the left terminal and the first tap, ~20K between the two taps, and ~40K between the second tap and the rightmost terminal. each of the taps had a separate wire running from it back to the tone controls board the vol pot was mounted on.

my questions are ... anyone know of a suitable replacement? i do have a 100K dual ganged but with only one tap per channel at 40K. could i use this and just hook the two wires from the tone control board (for each channel) that used to go to the separate taps together onto this one tap? or could i just leave the taps disconnected and not use the loudness switch? i also noticed this receiver appears to have a switch that boosts the treble ... perhaps what the second pair of taps are for?

as always any help greatly respected. i am so close to having this baby working and on my shelf i hope this is something that can be worked around.

[Nelson Pass]

I'm pretty sure you can stick it in there without problems -
if not, nothing lost except a little labor.

[gain]

Mr. Pass, thank you for your reply. this 4-tap pot was the one i pulled out (the original), so does this mean its ok to replace it with one with fewer or no taps and just leave the original connections going to the original taps disconnected?

many thanks again especially for all your contributions to diy audio!!!

[gain]

here is a diagram of the device i pulled out to make it more clear. both tap1 and tap2 are connected into the tone control circuit.

thanks.

[Zen Mod]

Originally posted by gain
here is a diagram of the device i pulled out to make it more clear. both tap1 and tap2 are connected into the tone control circuit.

thanks.

just find similar pot and mount it ;

if new pot have loudness tap , measure his position in overall resistance , then solder on it line in similar position of original pot .

redundant one ( second loudness line ) just leave disconnected .

in case that you have just plain volume pot , leave disconnected all these loudness wires and everything will be just fine ;

until you press any of loudness buttons ....... then you'll hear some buzz

[gain]

Originally posted by Zen Mod


just find similar pot and mount it ;

thanks for your reply, zen.

thats the whole issue. i cannot find, nor know even where to look for a similar pot. pots with one tap are a rarity for me, two taps per channel i have never seen. i'm sure the vol control function would be fine without hooking up the taps, but if someone hits the loudness switch by accident and it goes 'buzz' followed by a cloud of smoke pouring out it would just put a damper on my day.

[Zen Mod]

Originally posted by gain


thanks for your reply, zen.

thats the whole issue. i cannot find, nor know even where to look for a similar pot. pots with one tap are a rarity for me, two taps per channel i have never seen. i'm sure the vol control function would be fine without hooking up the taps, but if someone hits the loudness switch by accident and it goes 'buzz' followed by a cloud of smoke pouring out it would just put a damper on my day.

do not worry - it is just slight buzz in most cases .

for piece of mind - when you have it opened , just disconnect these loudness buttons from rest of circuit ;

in fact - you can always try it ( when you change a pot ) - press that button with volume on min , then rotate it slowly ........ and listen ;

been there ....... slight buzz is worse you can get ....and maybe even zero influence , depending on that circuit construction .

[unclejed613]

you could also terminate any open wires to ground through 39k resistors rather than leave them open.

btw i got a good laugh reading the title of this thread. it's a question i heard often in high school....

[gain]

many thanks to all. hooked up a reg 100K dual ganged vol pot and left all 4 of the taps disconnected. the stereo sounds AWESOME!!! what a difference a new pot made! before, it sounded a little muddy in the midrange and the treble was lacking. with the new pot, the treble is crisp and clear and the soundstage just came alive! not to mention the scratchyness is gone. i wish you all could be hear to hear it!

Greatful Dead, Touch Of Grey playing now.

now the only thing is it appears that my RIAA daughter board is not functioning properly. when i connect a turntable, i have to crank it to like 7 or 8 before hearing even a faint sound ... this couldn't have anything to do with the taps being disconnected, could it?

thanks again guys!!!! love this site!

[unclejed613]

could be you have a different taper on the pot. volume controls use log taper, linear taper would cause what you're describing.