Mayank
Well-Known Member
Hi:
I want to add an external VU meter board (with new/non-OEM replacement meters) in a GAS Son of Ampzilla power amplifier which I have painstakingly restored. The original VU meter design is fairly rudimentary with just a passive diode bridge and a 10K pot connected across the speaker terminals (attached and marked in red). Unfortunately, the original VU meters could not be resuscitated and are NLA.
While searching for an active driver for the new meters, I bought this VU meter board on eBay which is based around a dual opamp LM358. I used components from my own stock instead of the cheap capacitors, resistors and the possibly counterfeit opamp which came along in the "kit". No circuit diagram or parts list was sent. However, the double sided PCB was surprisingly well made.
The board does work (it also provides 12V to power the VU meter lamps). But I find the meters "lazy" and not as agile as I would like them to be even after adjusting the two 10K pots.
Question: Has anyone used this type of an external VU meter board before? Any suggestions on which components I should try changing to bring more life in the meters?
Best regards and stay safe!
Mayank
I want to add an external VU meter board (with new/non-OEM replacement meters) in a GAS Son of Ampzilla power amplifier which I have painstakingly restored. The original VU meter design is fairly rudimentary with just a passive diode bridge and a 10K pot connected across the speaker terminals (attached and marked in red). Unfortunately, the original VU meters could not be resuscitated and are NLA.
While searching for an active driver for the new meters, I bought this VU meter board on eBay which is based around a dual opamp LM358. I used components from my own stock instead of the cheap capacitors, resistors and the possibly counterfeit opamp which came along in the "kit". No circuit diagram or parts list was sent. However, the double sided PCB was surprisingly well made.
The board does work (it also provides 12V to power the VU meter lamps). But I find the meters "lazy" and not as agile as I would like them to be even after adjusting the two 10K pots.
Question: Has anyone used this type of an external VU meter board before? Any suggestions on which components I should try changing to bring more life in the meters?
Best regards and stay safe!
Mayank
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