If you can cause the amp to drop out by touching it, that's likely where the problem is. I thought that you had removed the muting transistors to eliminate one of the variables for the muting. It appears that the problem is either the pot or solder connections in that area.
Make sure that the problem isn't in the RCA jacks by gently moving them.
Make sure that the problem isn't in the RCA jacks by gently moving them.
Thanks again Perry.
That is exactly what I'm thinking, I will update ... now that I have the other fixed I want to get this one 100% right.
Update:
I wound up replacing the new pot I installed with the second one I bought (both the Bourns model listed upthread), thinking maybe I got a bad one. I seated it a little better this time, and maybe improved the soldering, and it is better but still not entirely robust. One channel will still flicker to minimum if you touch it just right.
I inspected the contacts carefully, cleaned well, etc.
Anyway, I think maybe these pots just aren't too good, they seem a little cheap or something. Maybe my expectations are unreasonable, or maybe I've missed something, but I don't think so. When the dial is turned all the way (either way), the two pins that have minimum resistance between them will jump to full resistance if the package encounters much force at all.
I wonder if anyone knows of a better option for gain pots for the gen 1 Orion 250 hcca / 2150 gx. The originals are "Piher" - I haven't found them anywhere, I think the company got bought or something actually.
Thanks.
I wound up replacing the new pot I installed with the second one I bought (both the Bourns model listed upthread), thinking maybe I got a bad one. I seated it a little better this time, and maybe improved the soldering, and it is better but still not entirely robust. One channel will still flicker to minimum if you touch it just right.
I inspected the contacts carefully, cleaned well, etc.
Anyway, I think maybe these pots just aren't too good, they seem a little cheap or something. Maybe my expectations are unreasonable, or maybe I've missed something, but I don't think so. When the dial is turned all the way (either way), the two pins that have minimum resistance between them will jump to full resistance if the package encounters much force at all.
I wonder if anyone knows of a better option for gain pots for the gen 1 Orion 250 hcca / 2150 gx. The originals are "Piher" - I haven't found them anywhere, I think the company got bought or something actually.
Thanks.
Thanks alot Perry I will check it out.
I put the amp back together, and it's basically behaving normally. I'm just adjusting the gain with a screwdriver, not pressing on it or anything, and no problem. If I stress it even a little it will probably cut, but I might just be expecting too much.
I wound up recapping the amp (4 rails, 2 power supply, 2 DIN/input power). The tech didn't clean very well, had physically oversized caps that looked like they were nearly shorting in a few places, and ...
he had 330uF (instead of the usual 470uF) in for the input stage rail caps. I guess this wouldn't matter too much or be a potential cause of the problem (?) but I thought I would change them anyhow.
I put the amp back together, and it's basically behaving normally. I'm just adjusting the gain with a screwdriver, not pressing on it or anything, and no problem. If I stress it even a little it will probably cut, but I might just be expecting too much.
I wound up recapping the amp (4 rails, 2 power supply, 2 DIN/input power). The tech didn't clean very well, had physically oversized caps that looked like they were nearly shorting in a few places, and ...
he had 330uF (instead of the usual 470uF) in for the input stage rail caps. I guess this wouldn't matter too much or be a potential cause of the problem (?) but I thought I would change them anyhow.
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