yup.. lots of peak with peak hold function, but not even remotely the same... despite any visual similarity.
JR
JR
Absolutely cool plasma VU-meter: IT WORKS!!!! /Pictures/
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moamps
Well-known member
Hi John,
thanks for the reply.
[quote author="JohnRoberts"]
... . I did prototype up one peak/VU meter using the 3914/15 meter chip years ago. I used the dB linear scale version (3915?). I found the chip was fast enough that I could electronically multiplex between dot and bar mode and Pk/VU inputs so I could do both functions with one chip...[/quote]
Ramsey have implemented this idea in their Led Bargraph/Peak Hold Meter kit, which can be found here:
http://www.ramseyelectronics.com/downloads/manuals/PH15.pdf
There was an article on that kit a while back, published in the German Mega Magazin 4/1995. I believe I could dig up the schematic for those interested.
The LM 39xx uses a fast parallel AD-converter. I once used a discrete AD converter consisting of a bunch of LM339's and buffers to scan 30 audio channels. From my experience, the LM39xx can drive directly up to 8 channels (before it reaches its CS and dissipation limits).
Regards,
Milan
thanks for the reply.
[quote author="JohnRoberts"]
... . I did prototype up one peak/VU meter using the 3914/15 meter chip years ago. I used the dB linear scale version (3915?). I found the chip was fast enough that I could electronically multiplex between dot and bar mode and Pk/VU inputs so I could do both functions with one chip...[/quote]
Ramsey have implemented this idea in their Led Bargraph/Peak Hold Meter kit, which can be found here:
http://www.ramseyelectronics.com/downloads/manuals/PH15.pdf
There was an article on that kit a while back, published in the German Mega Magazin 4/1995. I believe I could dig up the schematic for those interested.
The LM 39xx uses a fast parallel AD-converter. I once used a discrete AD converter consisting of a bunch of LM339's and buffers to scan 30 audio channels. From my experience, the LM39xx can drive directly up to 8 channels (before it reaches its CS and dissipation limits).
Regards,
Milan
Do anyone know where to find the plasma-meter glass for the SSL meters? Shaved or non-shaved version - our source seems to have dried up..
Jakob E.
Jakob E.
[quote author="moamps"]Hi John,
thanks for the reply.
[quote author="JohnRoberts"]
... . I did prototype up one peak/VU meter using the 3914/15 meter chip years ago. I used the dB linear scale version (3915?). I found the chip was fast enough that I could electronically multiplex between dot and bar mode and Pk/VU inputs so I could do both functions with one chip...[/quote]
Ramsey have implemented this idea in their Led Bargraph/Peak Hold Meter kit, which can be found here:
http://www.ramseyelectronics.com/downloads/manuals/PH15.pdf
There was an article on that kit a while back, published in the German Mega Magazin 4/1995. I believe I could dig up the schematic for those interested.
The LM 39xx uses a fast parallel AD-converter. I once used a discrete AD converter consisting of a bunch of LM339's and buffers to scan 30 audio channels. From my experience, the LM39xx can drive directly up to 8 channels (before it reaches its CS and dissipation limits).
Regards,
Milan[/quote]
Yes, that chip is essentially a flash convertor so easily capable of multiplex several times. My only observation about the article linked to is that instantaneous peak may not be optimal for audio work.
Back a few decades ago when I worked on mine, I settled on PPM standard for my peak meter characteristic. IIRC something like 4 mSec attack. I tweaked the release to be similar to RMS/Ave characteristic for best display visual.
JR
thanks for the reply.
[quote author="JohnRoberts"]
... . I did prototype up one peak/VU meter using the 3914/15 meter chip years ago. I used the dB linear scale version (3915?). I found the chip was fast enough that I could electronically multiplex between dot and bar mode and Pk/VU inputs so I could do both functions with one chip...[/quote]
Ramsey have implemented this idea in their Led Bargraph/Peak Hold Meter kit, which can be found here:
http://www.ramseyelectronics.com/downloads/manuals/PH15.pdf
There was an article on that kit a while back, published in the German Mega Magazin 4/1995. I believe I could dig up the schematic for those interested.
The LM 39xx uses a fast parallel AD-converter. I once used a discrete AD converter consisting of a bunch of LM339's and buffers to scan 30 audio channels. From my experience, the LM39xx can drive directly up to 8 channels (before it reaches its CS and dissipation limits).
Regards,
Milan[/quote]
Yes, that chip is essentially a flash convertor so easily capable of multiplex several times. My only observation about the article linked to is that instantaneous peak may not be optimal for audio work.
Back a few decades ago when I worked on mine, I settled on PPM standard for my peak meter characteristic. IIRC something like 4 mSec attack. I tweaked the release to be similar to RMS/Ave characteristic for best display visual.
JR
SSLtech
Well-known member
[quote author="gyraf"]Do anyone know where to find the plasma-meter glass for the SSL meters? Shaved or non-shaved version - our source seems to have dried up..[/quote]
I have three un-shaved... It sounds like this project won't work with them (they're 200 segment anyway, so I was wondering how deep the changes would have to go...)
PM me if you're interested...
Keith
I have three un-shaved... It sounds like this project won't work with them (they're 200 segment anyway, so I was wondering how deep the changes would have to go...)
PM me if you're interested...
Keith
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