Just dab a bit of wire across the resistor to link it out. That will (should) connect pin 3 of the opamp to ground and remove ALL signal from that channel. If it is easier you can apply a short across that 47pF cap instead.
Hi - just for clarity, you are shorting the right channel’s resistor and not the left one (shown as example in the attachments)?
A friend just got a hold of me and told me he has an oscilloscope. Going to be a while tho till I can see him. He was wondering if a shorted cap would cause this.
I think you have found the answer. Look at the circuit. The wiper of the volume control should go down to ground at minimum volume. Shorting the resistor does the same... and you have proved it kills the audio. So the pot should be doing the same.
Pots that don;t make it to zero are not that uncommon and the effect is made worse by high level input sources like CD players and the like.
You could try switch OFF and then measuring the resistance across that 10meg as you turn the volume down. It should ideally go all the way to zero (0.00 ohms). Try it. Use a suitable low ohms range on the meter.
Tell us what resistance value you measure on minimum volume.
Yep, did the same test with only CD and sound went off when shorting the R210. While I was at it, I just went ahead and tested all inputs the same way, separately.
With the volume turned off it has a value of 0.40 then increases turning it up. Checked the left side it was 0.00
0.00 is what it should.
What units is the 0.40 range showing? In other words what value resistor would give that sort of reading?
For example would a 470 ohm show as 0.47 on your meter on that range meaning 0.47k ohm. Just curious what the resistance actually is. I would guess at least 40 ohm and if it were 400 ohm then that would still be loud at minimum volume.
Looks like that is the problem though.
What units is the 0.40 range showing? In other words what value resistor would give that sort of reading?
For example would a 470 ohm show as 0.47 on your meter on that range meaning 0.47k ohm. Just curious what the resistance actually is. I would guess at least 40 ohm and if it were 400 ohm then that would still be loud at minimum volume.
Looks like that is the problem though.
Realistically it is to replace the volume control.
The control is just a potential divider of 50k total resistance. The moving wiper travels between the top and bottom of the resistive track. At the bottom end it should fully go to zero ohms removing all audio.
It would still be interesting to know what units your 0.40 was though, whether it is 40 or 400 ohms for instance.
0.40 as in 0.40 ohms would be so low as to essentially still remove all audio.
The control is just a potential divider of 50k total resistance. The moving wiper travels between the top and bottom of the resistive track. At the bottom end it should fully go to zero ohms removing all audio.
It would still be interesting to know what units your 0.40 was though, whether it is 40 or 400 ohms for instance.
0.40 as in 0.40 ohms would be so low as to essentially still remove all audio.
FWIW Try rotating it fully back and forth a handful of times to see if that helps.
Prior thread on the ALPS pot https://www.diyaudio.com/community/threads/need-volume-pot-adcom-gfp-565.316473/
eBay looks to be the place to go for replacement, but maybe others will chime in.
Prior thread on the ALPS pot https://www.diyaudio.com/community/threads/need-volume-pot-adcom-gfp-565.316473/
eBay looks to be the place to go for replacement, but maybe others will chime in.
The Adcom unfortunately uses a pot with a loudness tapping (that extra terminal) and that makes replacements much harder to come by.