I'll also pull the volume control and give it a good testing it's pretty easy to remove and install, so it won't be a PITA. Oh, and just for laughs, have you swapped out the speaker connections Left to Right and ruled that out? Stranger things have happened to me. Hope you don't have to go there.ĭepending what you find, and if you want to keep t he set forever, you might want to consider swapping out the 7189 sockets for decent porcelain ones, as these do tend to turn crispy over the decades. Finding replacements or work arounds could get interesting. An Ohmic sweep out of circuit with a vtvm could exonerate or condemn the controls. Yeah, could be a bad control too, but not all that likely.
Uneven volume level trakaxpc generator#
I'd also hook up the audio signal generator so I could measure the AC voltages as well If one channel is way different, from the other you have located the problem stage.
I'd start at the outputs and measure screen plate and cathode voltages or whatever the bias arrangement is and work backwards. Next time you do a recap job on a nice amp like this, you'll probably replace all of 'em at the same time. Like anything with a yellow or better multiplier will prpbab y have drifted on up towards carbon heaven. My money would be on a way out of spec resistor if you have totally recapped the set and done the obligarory tube swapping, retentioning of sockets and deoxit routine. Now, I originally thought that maybe the ganged volume control might have one side that was out of spec.but wouldn't switching to mono negate that? And for that matter, if the volume level is lower on the right side even in mono, wouldn't that rule out the front end of the amp and put the fault with the output stage? I gave it an overhaul.recapped, replaced all out of tolerance resistors, checked (and even rolled) the tubes no difference. Switching to mono does not make a difference. The problem mostly disappears when the volume gets to mid-level and beyond. For as long as I've had it, the volume level is incredibly mismatched from left to right channels.as in I have to have the balance control set at the 3 o'clock position to achieve roughly the same volume level from both. It's a Fisher X100 amp running 7189 outputs. I'd like your input.I'm sure you guys will come up ideas that I haven't thought of. I have not tried diagnostics yet, but I am getting ready to (probably on Christmas Day).
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