Is my phono stage stuffed


Hi. I have a MF NuVista M3 Integrated amplifier. As of yesterday the left channel of its phone stage has dropped out either altogether and just a emitting a faint scratching sound and occassionally it comes back to normal life but for a minute at most.

I believe it to be the left channel of the phone stage because:

1) I get sound out of both speakers when the source is switched to CD;

2) I switched the tone arm cable plugs at the phono stage RCA input terminals - left with the right and vice versa and still there is no output of the left speaker.

3) I double checked the grounding of the tone arm to the grounding of the amplifier. At a very low minimum volume I induced the typical "hum" generated by not grounding but the hum only occurred in the right speaker not the left.

Any ideas anyone? anything else I should check test. Unfortunately I have no other phono stage to check if everything else is working as it should be.

cheers
flyinglion2000
>>05-14-09: Stringreen
The spray stuff is not a permanent fix<<

This is poor advice.

No cleaner is a permanent fix because most controls and/or switches will require occasional maintenance.

There is no need to replace any switch or control mechanism when a simple cleaning alleviates the problem.
Just had the same problem with an Audio Research pre-amp.Played with selector switch,moving it alittle bit each way and presto, full sound. Gave it a spritz,good as new.Always try the simple fix first before dishing out some cash.
. . . respectfully disagree. Why would you replace a part that only requires cleaning? If you spend a ~$100 to replace the selector switch (if that is indeed what's wrong) it's no less susceptible to getting dirty again than the cleaned one.
I have a NuVista preamp and at one time the selector switch was causing a similar problem. It was resolve when I opened up the preamp and gave the switch a shot of cleaner. (this issue also happened with a marantz preamp I had years ago).

The only other "simple" check is to verify the issue isn't with your cartridge. If you have another table you can plug in this would be a quick check. Or plug your table IC's into another input and see if you have a signal from both channelsvfrom it. It will sound bad and faint but you should may be able to hear if you have a signal. If the table is the source, the solution may be as simple as remove-clean-replace your cartridge headshell leads.

If none of these work you may either have a bad cartridge, or something more significant going on with your NuVista. My money would be on the selector switch being your problem.