Simoc wrote:

Hi!

I got Technics 323 tuner amp, which is lacking a volume pot. It has
balance adjustment on the same knob, too. The knob came with it, it has
a "head" and "sleeve" which both have the same radius, and have no
space between them.

So might the balance adjustment be done so that the "head" just adjusts
one channel and the sleeve the other, and thus their ratio could be
adjusted, and when the volume is adjusted, both of them (ie. the entire
knob) are turned same amount?

What might be the name of the pot of such kind (a stereo pot having the
both channels separately adjustable?)

Then there is one more problem. There is a 5-wire ribbon cable for
connection of the pot...what might be the pinout? Or if anyone doesn't
know, how could I analyze it with a scope maybe? It just cannot be
easily done by analyzing the circuit, since the mainboard is very
complex and has a lot of stuff above it, and the device hasn't a
detachable bottom, so disassembling for analyzing the circuit would be
quite an infernal job...:

The logical thing to do is use a standard ganged pot and lose the
ability to adjust them separately.

Re the pinout, again the logical thing is to connect all wires together
each via a say 1k resistor, switch on and use a sig gen or finger to
find out which has no sensitivity (common ground), which has max
senitivity (to wipers of pot tracks) and the other 2 will be the high
ends of the pot tracks.

If you want to find one of these pots its a lot of extra work for not
much, but if you do the search term is 'cheapo 1970s pos design.'


NT