Douk VU3 VU Meter Review (Updated Version)

[Robbo99999]

Why another review? You reviewed this September 24. 2021.

Holy crap Batman, what's going on here!?

Douk VU3 Review (VU Meters)

This is a review and detailed measurements of the Douk / Little Bear VU3 dual analog VU meter and 2-way amplifier/speaker switcher. It is kindly sent to me by testing by a special member. VU3 costs US $140 from Amazon including Prime shipping. The VU meter are the "paper back" ones which I...

www.audiosciencereview.com

 

[KEFCarver]

I also posted a review of the Douk VU3 in ASR as well and my big problem with it was that it boosted the low end frequency response by 1dB at 20Hz, which bothered me and so I reached out the company and they said that problem should be fixed, but I ordered a 2nd unit 2 months later and it had the same problem. But it worked well. If you are not dying for VU meters and want a better performing a/b switch, search ASR for "NJ&FXAUDIO PW-6". I've used to a/b both speakers and amps and it works very well.

 

[AdamG]

Why another review? You reviewed this September 24. 2021.

Holy crap Batman, what's going on here!?

Douk VU3 Review (VU Meters)

This is a review and detailed measurements of the Douk / Little Bear VU3 dual analog VU meter and 2-way amplifier/speaker switcher. It is kindly sent to me by testing by a special member. VU3 costs US $140 from Amazon including Prime shipping. The VU meter are the "paper back" ones which I...

www.audiosciencereview.com

It’s a revised and improved Version of the same gadget. Supposedly reduced noise and distortion.

 

[Red_Red]

I too am looking for a nice vu-meter with RCA pass through or even without output to use for example on an unused output of a dsp like a flex eight or the like. I've been thinking about doing a DIY one for a long time but really I'm a little lazy... or rather, I have something more important to do before that I'll talk to you about soon.

 

[KEFCarver]

It is pretty easy to make rca to banana cable adapters for this:

 

[NoxMorbis]

A and B are in parallel, so you could leave your main speakers wired as usual on the A terminals and use short dedicated wires from the B output to the vu-meter.
That way the audio performances should be unchanged (the vu-meter is a negligible load for a speaker amp).
You just lose the switching function of the Douk device.
And you could even measure the effect of this load as disconnecting it using the amp's B switch would be very practical for an A (speakers) / B (speakers + vu-meter) comparison.
And for quiet dark listening sessions it would be easy to disable the whole vu-meter parallel chain.


Makes me think that, if the consumption of the electronics is low enough, one might even power the whole thing with the 12V trigger output of one amp. For example with an AVR you can select per input if the 12v trigger should be powered or not. My Denon can supply 12v / 150mA, 1.8W. Could be just enough with the 12v to 5v down-converter and the vu drivers + leds. It would be safe though to disable the internal relays to limit power.

Or Douk could just make a VU meter without adding distortion?

 

[NoxMorbis]

Yes, I'm really interested in this device hence my on-going reflection and 'great' rating !

If the 100 W limit is properly specified, the current limit should apply to 4 ohm speakers (5 A rms = sqrt(100/4)) and the voltage limit to 8 ohm speakers (28 V rms = sqrt(100*8)).
As the typical speakers are less than 8 ohm impedance, that voltage limit might never be reached.
For example, assuming there is no large current in the meter thanks to the parallel route and a hypothetical constant 4 ohm speaker impedance, the voltage limit is equivalent to a 200 W power limit into 4 ohm (28*28/4).

The concept of a speaker-level meter seems to me inherently better than line-level from the sound fidelity perspective as the speaker amplifier has such low output impedance.

Line-level has the benefit of being listening-level independent if sensed before the volume setting, but the low voltage and limited power exposes to the problems you noticed on the line-level Douk meter (excessive load leading to heavy distortion).

Besides, as I use an AVR and digital sources I do not have access to an analog line-level signal (recent AVRs do not have analog outputs to connect recorders).
I do have the pre-out signal, but at my usual listening levels the voltage is so low that it's hard to extract it well from the noise (tested with a graphic equalizer).
The zone 2 or 3 outputs do generally have line level, but are cumbersome to use (need to switch them on each time) and I don't even get a signal for all sources (ex : hdmi).

Speakers do get consistent signal levels however.
This vu-meter seems to be the best solution for me.

Thank you so much Amir for this review.
I've been eyeing this on Amazon for a while but your previous review of a Douk device scared me.

So does that mean you will get it or avoid it?

 

[NoxMorbis]

Sorry to sound stupid but what do the meters measure? How are they calibrated?

And, why can’t you connect to your amplifier outputs in parallel, using a spur to the unit.

Everyone knows they measure an appeal to eye candy. lol

 

[NoxMorbis]

They do actually:

Douk Audio VU2 MIC+LINE Dual Analog VU Meter Stereo RCA Audio Splitter Switcher Box Audio Spectrum Display

Warm Tips Compatible with most audio devices, but cannot guarantee 100%. If there exists common ground noise, please add an isolation module between VU2 and your device. Features VU2 VU meter & audio splitter box is originally designed by Douk Audio: As an analog VU meter, with wired stereo RCA...

doukaudio.com

Probably more dirty than the latest version.

It’s a revised and improved Version of the same gadget. Supposedly reduced noise and distortion.

I PMed Amir about updating the title stuff to include the "updated version" information, so as to reduce confusion. Yes, this is the "updated" version that I sent to Amir. I talked with Douk, pointed them to Amir's first review of the VU3, and they said he is right, but the updated version fixed the distortion/noise problems. It's a lot better than the old version w/o VU, but close to the same running through the VU meters. Pretty lame of Douk not to improve that through VU noise. And, now we know why they didn't contact Amir!

 

[NoxMorbis]

I was just wondering when you tested it "route it through VU3" does that mean there is a bypass switch for the VU meters? Or did you just unplug it from the 5V power source? Someone on Amazon said you can plug it in, set it where you want it, then unplug the power and it will remember the settings and pass through the signal without the VU meter active. Will that remove the distortion?

 

[Milanraf]

These VUs look almost identical in style (PEAK led apart) to the ones of my first mixer Inkel MX-995...a tremendous revival...

Anyway I can't get the actual use of such a measurement instrument (if I can call it this way). Expecially with that -20/+5 scale and a sensitivity knob.
Which information it is supposed to report to the user? What does VU exactly mean when applied to power lines? Nothing I suppose.
The sensitivity knob had been probably put there just to reward the audiophool with needles dancing in the middle at the house usual listening level...

 

[amirm]

Sorry about the confusion you all. I revised the title to say it is the revised version and added a note to the body of the review as well.

 

[sarumbear]

Everyone knows they measure an appeal to eye candy. lol

But it’s distortion is measured and it’s called a “meter”?

 

[NoxMorbis]

These VUs look almost identical in style (PEAK led apart) to the ones of my first mixer Inkel MX-995...a tremendous revival...

Anyway I can't get the actual use of such a measurement instrument (if I can call it this way). Expecially with that -20/+5 scale and a sensitivity knob.
Which information it is supposed to report to the user? What does VU exactly mean when applied to power lines? Nothing I suppose.
The sensitivity knob had been probably put there just to reward the audiophool with needles dancing in the middle at the house usual listening level...

Exactly. It's a switch box, but the VUs are there for , hum, nostalgia.

 

[amirm]

The sensitivity knob had been probably put there just to reward the audiophool with needles dancing in the middle at the house usual listening level...

This was a much needed functionality in amplifier meters which didn't exist at the time VU were standard. You hardly saw them move especially with the slow ballistics of the larger ones. They also showed the wrong value depending on what impedance your speaker had which this can correct.

These devices do have one major functionality that doesn't rely on accuracy: that the fact that there is signal when it is moving. It stops you from going deaf if the volume is too high and you think nothing is playing. So I suggest you cut back on audiophool" commentary.

 

[amirm]

Exactly. It's a switch box, but the VUs are there for , hum, nostalgia.

To the extent you are trying to level match between two amps the meter can do that regardless of its accuracy across the range. And again, it can tell you if there is a signal or not. I hugely use this feature in my RME ADI-2 Pro display. So many times I am trying to troubleshoot what is going on. In some cases for example Roon claims to be playing but I see that the spectrum analyzer on RME is showing nothing, telling me there is an issue between them rather than downstream.

 

[NoxMorbis]

To the extent you are trying to level match between two amps the meter can do that regardless of its accuracy across the range. And again, it can tell you if there is a signal or not. I hugely use this feature in my RME ADI-2 Pro display. So many times I am trying to troubleshoot what is going on. In some cases for example Roon claims to be playing but I see that the spectrum analyzer on RME is showing nothing, telling me there is an issue between them rather than downstream.

Good points. I never thought about the two amps deal either. So, they do have functionality, just not traditional 'measurement' functionality.

 

[pseudoid]

Sorry to sound stupid but what do the meters measure?

My question is even more stupid:
Can you arrange a sit-down meeting for an honest-to-goodness and an open dialog with these VU meters?
Then, you two can engage in a 'calibration-session', and rely on them, in a relativistic manner.

Not that I am much of a fan of VUmeters, constantly staring at me.

 

[Milanraf]

This was a much needed functionality in amplifier meters which didn't exist at the time VU were standard. You hardly saw them move especially with the slow ballistics of the larger ones. They also showed the wrong value depending on what impedance your speaker had which this can correct.

These devices do have one major functionality that doesn't rely on accuracy: that the fact that there is signal when it is moving. It stops you from going deaf if the volume is too high and you think nothing is playing. So I suggest you cut back on audiophool" commentary.

I remember many power amplifiers with a x10 or so switch to change the range for better readability. Impedance apart, which is a known limit of power meters in amplifiers, this would be a more useful way to implement a sensitivity control. But a knob with no scale...
$130 just to know whether there's signal or not, may be viable for someone...

 

[AdamG]

Guys at this price we are getting eye candy only. It is not calibrated level instrumentation. Rough order of magnitude approximation.