Stereomour - assembly in progress Qs

danox574 · 1971

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Offline danox574

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on: February 19, 2013, 06:41:07 PM
I just finished routing the 6 RCA jacks down to the 3-way switch in my Stereomour and everything has gone very smoothly so far.  I stopped at this point to check for continuity and shorts in this wiring, and when I reached down, I found that the switch has four positions!  It seems that they are 1, 2, 3, and 1 again.  It seems to have been mis-manufactured with the stop in the wrong place.  The 12 points around the edge are all soldered in already and that's 12 perfect length wires I'd have to trim the ends off and lose a tiny bit of length on.  Thought I'd mention to new builders so they'd be aware to check their switch before assembly.  I think I will have to replace it because it'll drive me crazy just knowing it's there.  I will call tomorrow about the switch, might as well do it now before wiring up the volume pot and putting even more connections on it.

Also, while I was down there with my meter, decided to measure the volume pot assembly and I found that one of the pots in the stack is 105K across the outer terminals and the other is 90K.  This causes a 10% difference in resistance value that would control input volume to be different for each channel, but I don't think it would create a balance problem.  This is a voltage divider, and the ratio of the resistance at the wiper vs. the entire pot's resistance is what's important, not the value.  Correct?

-Dan



Offline Paul Birkeland

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Reply #1 on: February 19, 2013, 06:46:56 PM
Don't sweat the pot, try it before you pull your hair out by replacing it.

On the rotary switch, remove the nut and lock washer on the top of the plate, then slide the switch out from the bottom.  You will notice a silver washer on the switch that can be removed, and this switch has a little tab on it.  You will either need to move it clockwise one hole or counterclockwise one hole to go back to 3 positions.

Sometimes these washers slip around when the switch is installed, the switch itself will function with four positions, you will jut have the same input twice.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man