VU Meters on Stereo Out

[Richard Crowley]

Benefits:
1) They look "cool" or "retro", etc.
2) They might be useful for monitoring sound-pressure level (SPL) if they are calibrated appropriately, you have good monitor speakers AND A GOOD MONITORING SPACE.

Needed:
Some kind of buffer/driver amplifier circuit depending on exactly what meters you have. There are different kinds of meters that have "VU" scales. There are also many published circuits for VU meter driver amplifiers.

[Filthrill]

Yeah i too am planning to get into the VU game in my new studio space. I have an Otari MX5050 2-track reel-to-reel machine w/ VU meters on it & figured if i'm not doing much tape nowadays why not use it for the metering?

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[ripple_fx1]

the answer to your question is probably "nothing".

after the mix fader rather than the monitor volume control, right?
they won't cal to your daw input, so....
it could gain you consistency somehow.
is there a specification you must meet for deliverables?

maybe build a mic pre instead?

[completeidiot23]

yeah I was thinking like monitoring what is going to the speakers so after my interface mains knob. There is no specs I need to deliver just an idea i had. I've seen it done in other home studios.

I'm currently building a pre aswell.

[zvukofor]

just a week ago i made VU meter with big glowing TEAC meters for studio where i work. All young engineers were impressed )) But, alas, they need to learn how to use it for more than just beautiful "vintage" piece of gear. As for me - i cannot understand how you can mix without good old VU, it is like sailing without compass.

[zvukofor]

As for connection and buffer schematics: i've placed it on a separate output of audio interface, so you can freely adjust volume on monitors and still see full level at VU-meters. Otherwise you'll need to place it before external monitor controller.
Schematics: http://www.jlmaudio.com/AT51%20DIY%20VU.pdf

[Filthrill]

Originally Posted by zvukofor

As for connection and buffer schematics: i've placed it on a separate output of audio interface, so you can freely adjust volume on monitors and still see full level at VU-meters. Otherwise you'll need to place it before external monitor controller.
Schematics: http://www.jlmaudio.com/AT51%20DIY%20VU.pdf

This is a great link. Thank you. Would you have any insight, thoughts, or tips regarding using my 2-track Otari MX5050 reel to reel machine's VU meters. Normally not recording audio to it, just using the VUs on it for monitoring &...dare I say...looks! I would definitely be able to come out of separate outs of my interface like you mention. Also, just to make sure I understand you properly, the VU meters' "meters" will read the same level regardless of me adjusting volume on my monitor controller (Dangerous Monitor ST). Correct?!

[zvukofor]

Originally Posted by Filthrill

This is a great link. Thank you. Would you have any insight, thoughts, or tips regarding using my 2-track Otari MX5050 reel to reel machine's VU meters. Normally not recording audio to it, just using the VUs on it for monitoring &...dare I say...looks! I would definitely be able to come out of separate outs of my interface like you mention. Also, just to make sure I understand you properly, the VU meters' "meters" will read the same level regardless of me adjusting volume on my monitor controller (Dangerous Monitor ST). Correct?!

maybe it is too brutal to break Otari to get meters from it? )) I do not know, maybe it is bad for recording, or broken, or even of a bad quality, so you're not using it, than why not )) My Tascam was broken, so i get meters from it without any suggestions. Anyhow, you can always buy a new meters, all info is in pdf i linked to.

If you plug VU meters to separate output of an audio interface, you definitely can adjust level on a monitor outs without changing level at meters out, it is just a matter of how your interface' knobs works. And if you're using ST controller and not touching interface' knobs/soft faders, there're never be a problem.

[Filthrill]

Originally Posted by zvukofor

maybe it is too brutal to break Otari to get meters from it? )) I do not know, maybe it is bad for recording, or broken, or even of a bad quality, so you're not using it, than why not )) My Tascam was broken, so i get meters from it without any suggestions. Anyhow, you can always buy a new meters, all info is in pdf i linked to.

If you plug VU meters to separate output of an audio interface, you definitely can adjust level on a monitor outs without changing level at meters out, it is just a matter of how your interface' knobs works. And if you're using ST controller and not touching interface' knobs/soft faders, there're never be a problem.

I wasn't suggesting that I was going to tear my Otari apart. I was simply suggesting using the machine's VU meters for monitoring, while meters are still in the machine of course. I would not be listening to the machine's output so could care less about the sound of it. After all, the Otari has inputs so I would see no reason to pull the VU meters out of it! Haaha. The machine is located just to the left of my monitoring position so is easy to glance over at it.

[zvukofor]

Originally Posted by Filthrill

I wasn't suggesting that I was going to tear my Otari apart. I was simply suggesting using the machine's VU meters for monitoring, while meters are still in the machine of course. I would not be listening to the machine's output so could care less about the sound of it. After all, the Otari has inputs so I would see no reason to pull the VU meters out of it! Haaha. The machine is located just to the left of my monitoring position so is easy to glance over at it.

Hmm! Than there's nothing else you have to do except connecting Otari to your interface outputs ) Well, of course you need to calibrate meters for desired level, but you can do it just adjusting output level at your audio interface.

[Filthrill]

Originally Posted by zvukofor

Hmm! Than there's nothing else you have to do except connecting Otari to your interface outputs ) Well, of course you need to calibrate meters for desired level, but you can do it just adjusting output level at your audio interface.

Agreed. I think it'll look cool to clients & also looking at the needles on the VUs will obviously help me varify that I'm getting a certain level coming out of my interface. After all, they seem like really good quality meters!

[doulos30]

the circuit for a stereo meter driver is pretty simple but if you don't mind the wait all you would have to do is box something like this.

I'd go with a pair of these http://www.ebay.com/itm/Panel-VU-Met...90739891245%26

with this http://www.ebay.com/itm/New-VU-Meter...item3a716f6289

for under 100 you could have a set of meters on your desktop that your clients and you could stare at.

[Richard Crowley]

Those are nice-looking meters, but they appear to have built-in circuitry to connect audio directly to the meter. Those driver boards appear to be designed to use with conventional DC meters. I would not assume those two products are compatible with each other.

[Matt Syson]

Hi
As noted above VU meters are usually intended to be fed with audio. The only real 'problem' is that if fed from a source with significant impedance, the basic rectifier inside the meter will distort the audio. Hence it is usual to have a 'buffer' amplifier to isolate this possible distortion source from your audio. The card indicated a post or two back does not immediately strike me as suitable partly because it is suggesting a DC meter (which would actually probably be OK) but it would be rather better to have a balanced input, even if you are using it from an unbalanced signal line as it will significantly reduce any possible 'ground loop' or powering issues.
A 'quick and dirty, but perfectly acceptable stereo balanced buffer could be made using a TL074 and a handful of other parts (resistors and caps).
Matt S

[zvukofor]

This is what i've made recently. Simple schematics, as i've mentioned above, one dual opamp, balanced inputs, VU meters from old TEAC reel tape recorder. I want to make another one with old-stock Soviet military carbolite mA-meters, these one should look awesome ))) But, despite of eye candy effect, VU meters are excellent instrument to judge level, i cannot imagine how one can mix without VU, same as do not know how someone can record without PPM.

[Filthrill]

Ahh so ur using VUs from reel tape recorder too. Only i'm not tearing mine out. No, seriously, great job. They look really good.

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[nosebleedaudio]

A console I just wired used Large VU meters on the st buss.. A UTA console.
Most people know that VU meters ONLY are not 100% effective..
But, how many have even 15dB of dynamic range on the St Buss???
I would want a switch for selecting two different Levels, +4 and +10dB for example..
And they DO look cool...

I like the old MCI JH110 meters..Have several of those.

[zvukofor]

You do not need any switch if you're plugging those in audio interface - you can always calibrate "0" at any reference level you want just by reducing level at interface output where meter plugged in.
And, BTW, VU meters are so effective on judging musical levels, that we even have plugins with modelled VU meter dynamics. But this is not means you should not use digital PPM - i have DIGICheck on RME card, do not need an external one.

[nosebleedaudio]

Originally Posted by zvukofor

You do not need any switch if you're plugging those in audio interface - you can always calibrate "0" at any reference level you want just by reducing level at interface output where meter plugged in.
And, BTW, VU meters are so effective on judging musical levels, that we even have plugins with modelled VU meter dynamics. But this is not means you should not use digital PPM - i have DIGICheck on RME card, do not need an external one.

You missed my point, for different levels...

[zvukofor]

Originally Posted by nosebleedaudio

You missed my point, for different levels...

For different output levels or reference levels? I've told about reference levels, and if there's any need to make meter working with defferent input levels - no problem at all, you always can make a switch for a different amplification of buffer. I do not need one, have no equipment with -10dBv outputs.

[Franco]

Originally Posted by nosebleedaudio

A console I just wired used Large VU meters on the st buss.. A UTA console.
Most people know that VU meters ONLY are not 100% effective..
But, how many have even 15dB of dynamic range on the St Buss???
I would want a switch for selecting two different Levels, +4 and +10dB for example..
And they DO look cool...

I like the old MCI JH110 meters..Have several of those.

I recently built a pair of meters for a similar purpose using some Bach-Simpson VUs that came off a Ward Beck console. I wanted 3 switched options that would allow me to make "0VU" anything I wanted (one setting for -10, for mixing, another one around -9 for mastering that will then usually go out for vinyl and the third one for -6.5 that tends to be for really loud hip hop). I designed the (really basic) circuit around some trim pots, resistors and I even added a "fine calibration" trim pot for each meter that brings additional fine cal options (either a +/-0.5dB difference from the 12 o'clock position or -1/+1 dB depending on where you put the pot after each position's calibration)

I'm testing it out right now, so far so good! I just need to switch to whatever position I need based on what kind of work I'm doing. I didn't build a buffer amp because I'm using a dedicated output on my monitor controller, so noise back from the meters isn't an issue for me, but I'm considering adding a buffer amp because if these turn out great, I might decide to build some for sale and I know typically, people would want to put these across their main outputs.

Here's a pic of what they look like with the cards I made built in (rear panel had not been drilled at this point, and I added a 9v pack to power the LEDs, as I didn't want to use another outlet for the meters).

https://www.dropbox.com/s/6p07xnwm3s...922_185437.jpg

[dualflip]

Originally Posted by zvukofor

For different output levels or reference levels? I've told about reference levels, and if there's any need to make meter working with defferent input levels - no problem at all, you always can make a switch for a different amplification of buffer. I do not need one, have no equipment with -10dBv outputs.

He's not talking about reference levels, he is talking about the posibility of switching the scale

[Filthrill]

Which makes me have to say digital "digital VU meters r fine also." Hell, digital "anything" is fine. Especially if they don't have a sound.

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[David Kulka]

We have built a few Stereo VU Panel versions over the years. Our current one is a 2 RU unit that uses two "re-purposed" JH-24 meters and buffer amps. We re-configure the buffer amps for isolated ground electrically balanced in, with an input range of approx. -12 to +8 for zero VU.

As others have said, whatever you do, there really has to be a buffer amp to prevent distortion and unbalancing problems. And not all VU meters are equal, some have out of spec ballistics and some tend to be "sticky" or mechanically unreliable.

Rack Mount Dual VU Meter Panel, +4 Buffered XLR Inputs