I am currently working on a DAC/tube headphone/preAmp project, where I would like to add an analog VU meter like the ones found on eBay rated at 500µA.
I did manage to find some suggestions for a driver circuit, and I think it would make sense to draw inspiration form the circuit in figure 6, since the author says its intended to be used with the eBay VU meter.
Then it came to my mind that the scale on the VU meter is logarithmic while i am not sure if the op-amp circuit is. The VU meter is first of all a show-piece, so it does not have to be precise, but it would be best if its somewhat accurate. Can anyone tell me if the suggested circuit will actually work? or maybe point me in a direction of a circuit that will work with the VU meter?
I know there is a ton of driverboards on ebay, but I would prefer as solution that is integrated in my circuit, also so I can gain some knowledge about these meters.
I did manage to find some suggestions for a driver circuit, and I think it would make sense to draw inspiration form the circuit in figure 6, since the author says its intended to be used with the eBay VU meter.
Then it came to my mind that the scale on the VU meter is logarithmic while i am not sure if the op-amp circuit is. The VU meter is first of all a show-piece, so it does not have to be precise, but it would be best if its somewhat accurate. Can anyone tell me if the suggested circuit will actually work? or maybe point me in a direction of a circuit that will work with the VU meter?
I know there is a ton of driverboards on ebay, but I would prefer as solution that is integrated in my circuit, also so I can gain some knowledge about these meters.
Sorry I can't help - I just took the easy way and ordered a kit with the driver board included.
Best of luck!
Best of luck!
> the circuit in figure 6,
Where is figure 6??
The meter is Linear. The marks are log. VU meter only reads the TOP of the audio. This is good for radio or tape monitoring. For listening, we mostly listen nowhere near the top of the channel capacity, so the meter hardly moves.
Where is figure 6??
The meter is Linear. The marks are log. VU meter only reads the TOP of the audio. This is good for radio or tape monitoring. For listening, we mostly listen nowhere near the top of the channel capacity, so the meter hardly moves.
Put it between the dac and preamp. They are for full line level. There are also different sensitivities, the pro ones need 10db more drive then consumer line level. Measure the dac output and get an apropriate meter.
Figure 6 is in the second link of my first post.
I made the preamp circuit so that the VU meter will be connected directly to the dac output through a buffer, the preamp is then able to work in unity gain or at -20dB gain. So the VU meter is intended to show the output level of the dac, not the amplifier because I want it to have some movement.
But since the needle is linear and the scale is log, then I guess I would need a circuit that is log as well to make the needle follow the scale, right?
I made the preamp circuit so that the VU meter will be connected directly to the dac output through a buffer, the preamp is then able to work in unity gain or at -20dB gain. So the VU meter is intended to show the output level of the dac, not the amplifier because I want it to have some movement.
But since the needle is linear and the scale is log, then I guess I would need a circuit that is log as well to make the needle follow the scale, right?