Most volume controls are most linear from 9 to 3 o'clock. So if the sound is fine (not distorted) you are probably ok!
Stumped by preamp-amp issues
Hi all,
As the title says, I'm at a loss as to what is going on, so I'm turning to the community in the hopes you can help.
I have a Bryston 12B preamp that I bought new 25+ years ago. For the last year I've been running it balanced into an Audio Research D240 mkII amp, which is powering Martin Logan CLS IIz speakers. (Yes, I know this gear is old, but I love the sound.)
A few months ago, the 12B and D240 started distorting and power cycling. I started with the preamp because something similar had happened while it was still under warranty. I sent it to Bryston. Bryston replaced the power cord as a courtesy, but could find nothing wrong with the unit. It tested fine. I got it back and connected it to the amp, and the distortion and power cycling were still there.
I took the amp to Audio Research. They looked at it, bench tested, connected to their test systems, and could find nothing wrong. They did nothing else to it. The only suggestion I got from them was that the amp "sensitive to DC offset at the inputs and that can cause the unit to go into protect".
I got it back and connected it up to the preamp and speakers, and the distortion and cycling were gone.
However, now the system gain is much lower than it was. I now have to turn the volume on the preamp much higher than before (past 12 o'clock). I have a second amp that I can only run unbalanced and that gain is unchanged.
So what gives? Does anyone have any ideas or suggestions for what I might try? The system does not distort when I turn up the gain (no clipping), so I can do that, but would prefer not to.
Thank you in advance!
As the title says, I'm at a loss as to what is going on, so I'm turning to the community in the hopes you can help.
I have a Bryston 12B preamp that I bought new 25+ years ago. For the last year I've been running it balanced into an Audio Research D240 mkII amp, which is powering Martin Logan CLS IIz speakers. (Yes, I know this gear is old, but I love the sound.)
A few months ago, the 12B and D240 started distorting and power cycling. I started with the preamp because something similar had happened while it was still under warranty. I sent it to Bryston. Bryston replaced the power cord as a courtesy, but could find nothing wrong with the unit. It tested fine. I got it back and connected it to the amp, and the distortion and power cycling were still there.
I took the amp to Audio Research. They looked at it, bench tested, connected to their test systems, and could find nothing wrong. They did nothing else to it. The only suggestion I got from them was that the amp "sensitive to DC offset at the inputs and that can cause the unit to go into protect".
I got it back and connected it up to the preamp and speakers, and the distortion and cycling were gone.
However, now the system gain is much lower than it was. I now have to turn the volume on the preamp much higher than before (past 12 o'clock). I have a second amp that I can only run unbalanced and that gain is unchanged.
So what gives? Does anyone have any ideas or suggestions for what I might try? The system does not distort when I turn up the gain (no clipping), so I can do that, but would prefer not to.
Thank you in advance!