Hello everyone,
I've got a MF Trivista 300 integrated I just picked up (for a temporary replacement while my other amp is being fixed) and it seems the previous owner wasn't all that truthful about the condition of his amp. Got to love my luck. Anyway, I find myself in a position that I have to try to fix what I have with the much needed help from you lot.
The amplifier seems to play just fine with no distortion or obvious signs when playing at moderate levels of volume. It is when you go past the 11 o'clock mark on the dial that suddenly the right channel will immediately jump to a very high volume and will not adjust up or down unless the knob is just below a very specific point at 11 o'clock on the dial. The left channel will go up an down the entire range linearly despite the right channel being 'stuck'. Below 11 o'clock they work perfectly fine in a linear fashion and at the same volumes .
Again, this is a very specific spot on the dial where it acts almost like an 'on' and 'off' switch on the right channel from being at normal volume and then jumping suddenly.
The dial does not produce noise when moving up or down which leads me to believe it is not just a matter of cleaning the potentiometer, but something in the preamp section (perhaps?). What do you guys think is the issue and how could I fix it? Thank you all in advance!
I've got a MF Trivista 300 integrated I just picked up (for a temporary replacement while my other amp is being fixed) and it seems the previous owner wasn't all that truthful about the condition of his amp. Got to love my luck. Anyway, I find myself in a position that I have to try to fix what I have with the much needed help from you lot.
The amplifier seems to play just fine with no distortion or obvious signs when playing at moderate levels of volume. It is when you go past the 11 o'clock mark on the dial that suddenly the right channel will immediately jump to a very high volume and will not adjust up or down unless the knob is just below a very specific point at 11 o'clock on the dial. The left channel will go up an down the entire range linearly despite the right channel being 'stuck'. Below 11 o'clock they work perfectly fine in a linear fashion and at the same volumes .
Again, this is a very specific spot on the dial where it acts almost like an 'on' and 'off' switch on the right channel from being at normal volume and then jumping suddenly.
The dial does not produce noise when moving up or down which leads me to believe it is not just a matter of cleaning the potentiometer, but something in the preamp section (perhaps?). What do you guys think is the issue and how could I fix it? Thank you all in advance!
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. This included placement of a film cap and resistor underneath the board and running leads from the motor of the volume pot in order for this to work. It is the only solution.
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. This included placement of a film cap and resistor underneath the board and running leads from the motor of the volume pot in order for this to work. It is the only solution.