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Daddy-O Daddy-O Baby
Since I've started also using a digital system, I've continued to also use a pair of VU meters to monitor levels on the DAW soundcard recorder output. Right now I'm using a pair of the little Modutecs that were used in 3M M-79s , since I happened to have two of them as spares. The DAW recorder output goes to a buffer amp and then to the VU meters, unless it's going to the M-23 which has VU meters of its own.
This week I went up to the NCSL conference in Boston for my work, but I also visited a friend who works in New London, CT. He has rather a lot of stuff in the old farmhouse he lives in and was generous enough to give me a Third Edition of the Radiotron Designer's Handbook (not as big as the Fourth Edition, but still very useful) and a pair of big, 4 1/2" Simpson Model 49 dB meters. I'm going to try them in place of the Modutecs.
My M-23 has Simpson VU meters the same size. What's interesting about these big Simpson meters is that they apparently predate the VU standard. The scale has markings from -10 dB to +6 dB, and the 0 dB point is about where -3 dB is on a VU meter. They also take a bit more voltage, since 0 dB requires 1.73 V , not 1.23V. They also have a 5000 ohm internal resistance, so they only require a 2500 ohm resistor in series to make a total resistance of 7500 ohms. Standard VU meters have an internal resistance of 3900 ohms and require a 3600 ohm resistor in series. It will take a little bit of use to get a sense of how the ballistics of these old meters compares with a VU meter.
The bottom line, of course, is that they are big, easy to read, still seem to work and look really cool!
Cheers,
Otto
This week I went up to the NCSL conference in Boston for my work, but I also visited a friend who works in New London, CT. He has rather a lot of stuff in the old farmhouse he lives in and was generous enough to give me a Third Edition of the Radiotron Designer's Handbook (not as big as the Fourth Edition, but still very useful) and a pair of big, 4 1/2" Simpson Model 49 dB meters. I'm going to try them in place of the Modutecs.
My M-23 has Simpson VU meters the same size. What's interesting about these big Simpson meters is that they apparently predate the VU standard. The scale has markings from -10 dB to +6 dB, and the 0 dB point is about where -3 dB is on a VU meter. They also take a bit more voltage, since 0 dB requires 1.73 V , not 1.23V. They also have a 5000 ohm internal resistance, so they only require a 2500 ohm resistor in series to make a total resistance of 7500 ohms. Standard VU meters have an internal resistance of 3900 ohms and require a 3600 ohm resistor in series. It will take a little bit of use to get a sense of how the ballistics of these old meters compares with a VU meter.
The bottom line, of course, is that they are big, easy to read, still seem to work and look really cool!
Cheers,
Otto