Musical Fidelitly Trivista 300 - Strange Volume issue

[Thewiredninja]

Hello, I am hoping someone can guide me in trying to fix this strange problem with volume control

I purchased this amp from a not-so-honest seller and have inherited some issues with it. Although the amplifier seems to play music just fine, the mute function works, both channels work etc the main problem is the Volume control. There is no crackling or cutting out, but there seems to be a channel mismatch in volume, especially in one channel.

Problem details: Left channel seems to be working perfectly in a linear fashion whereas the right channel is showing bizarre volume adjustments. When the volume knob is between 7 oclock to 9 o'clock position, the right channel is clearly at a lower volume then the left (to the point where I thought the channel wasn't working at all). Then when the volume is turned to about the 10 o'clock position both channels seem to immediately level out and all is well until around the 11 o'clock position. Beyond a very specific point on the dial at about 11:30 and beyond, the right channel will then shoot volume right up with distortion while the left channel all along seems to work just fine. Any idea what seems to be the issue? Again, I don't believe it's simply a dirty potentiometer as there is no scratching or static noises - but it could still be the pot nonetheless.

Any help is greatly appreciated!

 

[MaxwellsEq]

Hello, I am hoping someone can guide me in trying to fix this strange problem with volume control

I purchased this amp from a not-so-honest seller and have inherited some issues with it. Although the amplifier seems to play music just fine, the mute function works, both channels work etc the main problem is the Volume control. There is no crackling or cutting out, but there seems to be a channel mismatch in volume, especially in one channel.

Problem details: Left channel seems to be working perfectly in a linear fashion whereas the right channel is showing bizarre volume adjustments. When the volume knob is between 7 oclock to 9 o'clock position, the right channel is clearly at a lower volume then the left (to the point where I thought the channel wasn't working at all). Then when the volume is turned to about the 10 o'clock position both channels seem to immediately level out and all is well until around the 11 o'clock position. Beyond a very specific point on the dial at about 11:30 and beyond, the right channel will then shoot volume right up with distortion while the left channel all along seems to work just fine. Any idea what seems to be the issue? Again, I don't believe it's simply a dirty potentiometer as there is no scratching or static noises - but it could still be the pot nonetheless.

Any help is greatly appreciated!

It sounds like you need a new potentiometer. You could try cleaning it first.

 

[Thewiredninja]

It sounds like you need a new potentiometer. You could try cleaning it first.

I really hope that's all it is. I forgot to mention that the amplifier also tends to 'restart' now and then. This is very difficult to repeat as it seems completely random - doesn't matter how long the amp has been on, how loud the music is etc. I'm assuming this is due to a biasing issue and the circuitry is going through a safety reset or sorts... possibly related to the differences in volume from either channel's

In any case, I'll go ahead and order a new potentiometer. If there are any other suggestions given the new information posted, please let me know.

 

[Thewiredninja]

Update: PROBLEM FIXED.

It was indeed a faulty potentiometer. There are NO stock replacements unless you manage to find a used one. The replacement 50ax2 by Alpine will not fit, despite it being the same model number - it is much too large. Anyone who runs into this problem will have to modify a few things in order to retrofit a new one