Sherwood P-965 preamp - Volume changes on screen, but output stays high

[david winter]

Hello,
I have a P-965 which is almost working.
At first, both control knobs (Multi-Control / Volume) weren't responding correctly, so I cleaned the rotaty encoders, and they now work as new.
However, the volume stays to the maximum level even though I the output level changes on the screen and varies within -70dB and +20dB.
I would like to know if this is a known issue and what could be the cause. I'm using the analot Aux Output.

Also, is it possible to check the actual firmware version ? Where can I find the latest version as well as the utility for flashing, considering that this preamplifier is 20+ years old ?
Last: I see one DB9 serial port and one USB port above the optical inputs. Can the USB be used or do I need a DB9-to-USB adaptor ?

Thanks.

 

[Eppie]

Hello,
I have a P-965 which is almost working.
At first, both control knobs (Multi-Control / Volume) weren't responding correctly, so I cleaned the rotaty encoders, and they now work as new.
However, the volume stays to the maximum level even though I the output level changes on the screen and varies within -70dB and +20dB.
I would like to know if this is a known issue and what could be the cause. I'm using the analot Aux Output.

Also, is it possible to check the actual firmware version ? Where can I find the latest version as well as the utility for flashing, considering that this preamplifier is 20+ years old ?
Last: I see one DB9 serial port and one USB port above the optical inputs. Can the USB be used or do I need a DB9-to-USB adaptor ?

Thanks.

The Aux Out is likely the same as the Tape Mon Out. It is a fixed level signal for monitoring or recording and not affected by the volume control. You need to use the "Pre Out" connections to the left. If only using two speakers use the "Front" left and right and set the pre-amp to stereo mode (2-channel).

The unit may not have upgradable firmware. You need to connect a monitor to the Monitor Out jacks and access the setup menu, if there is one. The top monitor out is component video (RGB) while the yellow jacks are composite and the round DIN style are S-VHS. You will only be able to connect this pre-amp to a vintage monitor with analogue inputs. The DB9 connector is for service technicians only.

These old analogue AV units are only good for retro setups like old gaming hardware, VCRs and analogue TVs. You can ignore the video connections and just use the analogue audio inputs and treat it as an audio pre-amp, but there is little value in anything with only analogue video and no digital processing.

 

[david winter]

Thanks for your infos. Never mind, indeed I should have used the Preamp Out instead of Aux Out. The Volume control works as expected with the correct output. The number of RCA plugs was confusing. I almost work on much older stereo equipment.

 

[lovinthehd]

I seriously doubt there's any firmware update for that unit even back in the day....let alone the company being gone now.