advertisement


Amplifier issue

Conan

Conan

Loop digger
I love my JVC AX 1010 to bits but lately it has developed a fault so I need some advice.
When I listen to music at low volume sometimes the left channel cuts out, other times its the right channel.
If I turn the volume up both channels work fine.
The problem seems to happen in all the inputs including the dac one.
Why does this happens and how can it be fixed?
 
Have you tried cleaning the o/p speaker sockets and plugs? And/or any speaker selection switches or a switch in a headphone socket. For old kit, I tend to associate the symptoms you describe as being due to some contacts somewhere which have tarnished. High current/voltage can 'break though' the tarnish, but it then can reform and become too much for lower voltages to break though.
 
Or a volume knob playing up at one end of it's travel because modern signals are louder than old amps were optimised for.
 
Worn volume control would be my best guess. Occasionally, exercising the control will help but it's fairly common for channel tracking at low volume to be an issue. If the dual potentiometer is unsealed, flushing with IPA (alcohol not beer!) with tissue to soak up the residual. If sealed - replace the control or the entire amp.
 
As has been said, sounds like it's probably the volume potentiometer, a bit of switch cleaner should help (hopefully the pot easily accessible) look for a little hole to spray it into whilst turning the volume knob (while the amp is unplugged) and then leave to dry before testing.
 
Usually sorts it as others say. Power off, lead out, lid off, spray, wiggle, spray. Lid on. Leave to dry for an hour. Reconnect, cross fingers. I've resurrected some right old dogs like this, stuff that has been rusting in sheds and garages for years.
 
Just my luck.
Bought WD40 contact cleaner unplugged amp took lid out sprayed the volume pot whilst moving it. Dry for a couple of hours, reconnect it and the issue mantains and now when I use the remote control for the volume the light flickers but nothing happens. Just my luck...
 
There is probably a drive belt for the remote volume control and that may have been last it’s best being quite a few years old, the contact spray could have finished it off.
 
Funnily enough I have the same problem with my Demon which runs all day low volume However its just the left channel. Put it into get fixed was told it was the capactor. Sadly the problem has not gone away the amp is less than 2 years old and one of there top models. Will send to Demon work shop now. Meantime have bought the Yamaha A-S1100 what an amp with a great Phono stage. will keep the Demon when fixed as a back up.
 
You can use WD40.. sparingly! It's best in conjunction with other cleaners though as using it alone could mean needing to use far too much.
 
Conan said:
Just my luck.
Bought WD40 contact cleaner unplugged amp took lid out sprayed the volume pot whilst moving it. Dry for a couple of hours, reconnect it and the issue mantains and now when I use the remote control for the volume the light flickers but nothing happens. Just my luck...
Click to expand...


Does the remote control operate a motorised volume pot? i.e. you should see the control rotate? Are you saying it no longer rotates? Or?...

What kind of loudspeaker output sockets/posts does the amp use? Does it have switchable speakers or a headphone socket that disconnects the loudspeakers?

I ask, because I've often found that kit playing at very low levels for many years can develop 'tarnish diodes' on the speaker outputs (or sometimes on internal switches). I know the suspect people generally think of is the volume control. But I've tended to find mechanical switches also give problems on some old equipment when the signal levels are low.
 
The the remote control used to operate the motorised volume pot. Not anymore.
I have the speaker cables directly connected to the biding posts.
There is a selector for speaker pair 1 and 2
 
Conan said:
Anyone know of someone who can restore this amp back to its glory?
Click to expand...
I'm sometimes have to travel to Oldbury and go past Junction 10, I gather that you're that way on. I could take a look, It'll be a few weeks though. I've got some medical procedures to go through and I'm in Spain a couple of times in the next two months (provided all goes well). I would advise sending it to Jez (Arkless) for a service and check over though, he's a highly knowledgeable guy. I used to work in electronic repair myself but stepped out of it to persue a different career a good while ago (live sound engineering) and Jez's knowledge trumps mine.
 
Jim Audiomisc said:
Does the remote control operate a motorised volume pot? i.e. you should see the control rotate? Are you saying it no longer rotates? Or?...

What kind of loudspeaker output sockets/posts does the amp use? Does it have switchable speakers or a headphone socket that disconnects the loudspeakers?

I ask, because I've often found that kit playing at very low levels for many years can develop 'tarnish diodes' on the speaker outputs (or sometimes on internal switches). I know the suspect people generally think of is the volume control. But I've tended to find mechanical switches also give problems on some old equipment when the signal levels are low.
Click to expand...
Yes, I've experienced similar. I also suspect that the volume control is no longer operating via the remote because the contact cleaner has eaten a belt or a degraded plastic gear.

To the OP, can you hear a motor turning when you press the volume keys on the remote?
 
You must log in or register to reply here.


advertisement


Back
Top