• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

adding VU-meters in the audio chain?

Taketheflame

Member
Joined
Mar 14, 2020
Messages
31
Likes
33
Reviving this thread to share a recent addition to my desktop setup/a possible option anyone still wanting a VU meter box might consider...

VUmeter.jpg


This is another Little Bear/Douk model (the VU2). This one has considerably bigger meters than the other, smaller Little Bear model mentioned here. It also functions as an RCA splitter (so it's not strictly eye candy).

I haven't done any serious measurement/testing with this one like ajawamnet did with the other Little Bear unit, but in Db mode and using a sine wave from Audacity through a DAC (probably not the best, but just as a quick rough test) it doesn't have the panning issues that the unit they tested did (the needles move accordingly as panning is adjusted while the tone is playing). Needle movement is nice and smooth too. I really like this one so far :).
 

jshelbyj

Member
Joined
Feb 11, 2021
Messages
44
Likes
38
Joined
Mar 2, 2021
Messages
19
Likes
4
Maybe something slightly related.. I´ve set up my little Pi-Streamer, DAC, Topping L30 headphone stack. And as good as it sounds and as flexible as it is, I still find myself enviously looking at the dancing bars on the RME ADI-2 FS graphic eq.

Is there any way to accomplish something like this with maybe another Pi and a little display? Or at least to use this for an old-school digital VU meter?
 

MakeMineVinyl

Major Contributor
Joined
Jun 5, 2020
Messages
3,558
Likes
5,871
Location
Santa Fe, NM
For a power amplifier, you really want a watt meter. A traditional VU meter tells you nothing beyond the fact that it is wiggling. VU meters are useful on things like analog tape machines, but even then they take some skill to interpret what the meter is telling you. For instance, a VU meter is basically useless for detecting extremely sharp transients, since a VU meter only detects the average value of a signal. Analog tape (at least on professional machines, not cassettes) is very forgiving of overload, so VU meters are appropriate.

European mixing consoles frequently use peak program meters (PPMs), which detect the peaks of the signal (sort of, since the meter movement is still analog and mechanical). They have a lengthy release time constant.

If you just want VU meters .......because......, there are lots of alternatives but just be aware that you're not getting very useful information from them.
 

sergeauckland

Major Contributor
Forum Donor
Joined
Mar 16, 2016
Messages
3,440
Likes
9,100
Location
Suffolk UK
I've always thought VU stood for Virtually Useless, as they're too slow to indicate peaks, and not frequency weighted to indicate perceived loudness, such as the ITU recommendation or even the Orban or Durrough meters.

On tape machines they're good for line-up tone, and not much else.

I built a Type 1 PPM with both digital and analogue inputs, and although even a Type 1 PPM is a quasi-peak meter, at least it'll indicate only -1dB on a 10mS pulse.

S
 
Joined
Mar 2, 2021
Messages
19
Likes
4
ahh.. the green glowing and dancing bars of an RME... still haven't found a way to replicate this nostalgia with a Pi or similar :-/
 

Ralph_Cramden

Major Contributor
Joined
Dec 6, 2020
Messages
2,574
Likes
3,468
ahh.. the green glowing and dancing bars of an RME... still haven't found a way to replicate this nostalgia with a Pi or similar :-/
Not 100% there yet, but getting pretty close. Running on a Pi Zero, which is just about maxed out CPU wise. Will try a Pi 3A next week. Memory isn't an issue.

 

AdamG

Proving your point makes it “Science”.
Moderator
Forum Donor
Joined
Jan 3, 2021
Messages
4,636
Likes
14,918
Location
Reality
Reviving this thread to share a recent addition to my desktop setup/a possible option anyone still wanting a VU meter box might consider...

View attachment 118618

This is another Little Bear/Douk model (the VU2). This one has considerably bigger meters than the other, smaller Little Bear model mentioned here. It also functions as an RCA splitter (so it's not strictly eye candy).

I haven't done any serious measurement/testing with this one like ajawamnet did with the other Little Bear unit, but in Db mode and using a sine wave from Audacity through a DAC (probably not the best, but just as a quick rough test) it doesn't have the panning issues that the unit they tested did (the needles move accordingly as panning is adjusted while the tone is playing). Needle movement is nice and smooth too. I really like this one so far :).
This is the VU2 model already reviewed by Amir with other than acceptable results. Here is the review: https://www.audiosciencereview.com/...ouk-vu2-review-vu-meter-input-selector.26574/
 

Ralph_Cramden

Major Contributor
Joined
Dec 6, 2020
Messages
2,574
Likes
3,468
Running it on a Pi 3A+ fixes the issue. CPUs are loafing now, frame rate is much higher.

 

antennaguru

Senior Member
Joined
Jun 16, 2021
Messages
391
Likes
416
Location
USA
There are some meter driver circuit boards that use a pair of small audio transformers to sample the left and right signals, without resorting to direct connection with say 10K resistors to supply the samples to the meter amplifier (driver) circuitry. I would think those would have much less, and possibly no impact on the signals being sampled due to the higher isolation provided by the transformers.
 

Ralph_Cramden

Major Contributor
Joined
Dec 6, 2020
Messages
2,574
Likes
3,468

MakeMineVinyl

Major Contributor
Joined
Jun 5, 2020
Messages
3,558
Likes
5,871
Location
Santa Fe, NM
There are some meter driver circuit boards that use a pair of small audio transformers to sample the left and right signals, without resorting to direct connection with say 10K resistors to supply the samples to the meter amplifier (driver) circuitry. I would think those would have much less, and possibly no impact on the signals being sampled due to the higher isolation provided by the transformers.
Depends on the load reflected back through the transformers, the turns radio etc. I have a VU meter bank which has an op-amp buffer stage which drives the meters - I'd rather have that than a transformer which would most likely be of questionable quality. Really high quality transformers are very expensive. The VU meters on analog mixing consoles are either directly connected across the output line through a 3.6k resistor (old school), or use a buffer amplifier (somewhat less old school).
 
Top Bottom