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Douk VU3 VU Meter Review (Updated Version)

Rate this VU meter/Selector

  • 1. Poor (headless panther)

    Votes: 23 14.7%
  • 2. Not terrible (postman panther)

    Votes: 75 48.1%
  • 3. Fine (happy panther)

    Votes: 40 25.6%
  • 4. Great (golfing panther)

    Votes: 18 11.5%

  • Total voters
    156

amirm

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This is a review and detailed measurements of the Updated Douk Audio (Little Bear) VU3 VU meter and amplifier/speaker selector. It was kindly drop shipped to me by a member and costs US $139.
Douk VU3 Amplifier VU meter switch box switcher review.jpg

Both the case and the VU meters are top class. The metal box is heavy as to help keep it in place and the glass in front of the VU meters ultra clear. Picture above is a bit washed out relative to the smooth/vintage shading of the yellow color. The peak LED is an added bonus. Sensitivity control is smooth and nice to operate. The two selector switches activate what sounds like hefty relays providing some sense of quality.

The back panel is where the problem is *for me*:
Douk VU3 Amplifier VU meter switch box switcher back panel review.jpg


I don't want to route heavy/messy speaker cables through this just to have a VU meter. I rather have a line level one. But maybe your needs are different.

As you see power input is a USB-C jack but no supply is provided. I used a Samsung phone charger which worked well.

I first used whatever speaker cable I had to put the unit inline with my amplifier but that caused measurements to drop. So I built 1 foot bare wire speaker cables which worked better than any off-the-shelf banana cable.

Edit: this is supposed to be the updated version of the meter, solving the distortion issue in the last VU3 I reviewed.

Douk VU3 Measurements
The unit is rated at 100 watts maximum so I used a Topping LA90 as the amplifier. Here is the fresh measurements of that by itself:
Topping LA90 Amplifier Measurement.png


Superb performance as before. Now let's route it through VU3:
Douk VU3 Amplifier VU meter Topping LA90 measurement.png


We have fair bit of increase in distortion. Note that testing amplifiers at this level of distortion requires absolute attention to speaker wiring and termination. So likely the cabling had some contribution but it is impossible to separate that out. Let's put a pin in this for now and test SNR:

Douk VU3 Amplifier VU meter Topping LA90 SNR measurement.png


That's good. We have transparency there as well as in crosstalk:
Douk VU3 Amplifier VU meter Topping LA90 Crosstalk measurement.png


Now let's sweep into 4 ohm and see what the difference is:
Douk VU3 Amplifier VU meter Topping LA90 Power 4 ohm measurement.png


We see an increase in distortion with increasing power. As I noted, this can happen with less than optimal wiring. I checked my standard testing cables and they were sold. And as noted, I also made very short jumpers to connect the LA90 to VU3. My sense is that there may be some contribution for additional cabling. Most of this though is likely due to quality of the switching and speaker terminals in VU3.

Edit: Per member request, here is a test of hooking up the VU meter in parallel with amplifier speaker terminals:
Douk VU3 Amplifier VU meter Topping LA90  VU3 Loaded measurement.png


I only connected channel 2 to the VU meter and as you see, SINAD took a hit of 5 dB. Distortion is distinctly increased in that channel.

Conclusions
Douk nails the look and feel of the VU3. In addition, it doesn't have any of the horrendous loading problems of their other (line level) VU meters. Alas, the product is now inline with higher power speaker connection. With it, comes the limit of 100 watts and potential for degrading amplifier performance at higher power levels. I like VU meters but don't want to give up hard earned transparency in the amplifier I paid for. I like to see Douk produce a version of this with RCA input (and pass through).

As it is, the Douk VU3 is not for me. Your priorities may be different so you can decide otherwise.

------------
As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 
Last edited:

GWolfman

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P.S. It is "spring break" vacation time for the panthers and hence the reason there is none in the review picture....
LOL. Glad your able to still produce reviews despite their hiatus!

As always, much appreciated.
 

Doodski

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I first used whatever speaker cable I had to put the unit inline with my amplifier but that caused measurements to drop. So I built 1 foot bare wire speaker cables which worked better than any off-the-shelf banana cable.
Very interesting. The gas tight fit of bare copper is the better conductor.
 

Robbo99999

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Seems like it makes no sense to degrade performance and limit yourself to 100W for what could amount to a pretty gimmick! Should have no effect on performance and have no significant limits, praps that's one reason Amir mentioned it should be measuring at Line Level rather than after the amplifier.
 

tritopia

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It would have been better if an USB or AES or Toslink digital input was added to measure the absolute level.
In addition, if you can show the LUFS level, it will be more useful.
 
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amirm

amirm

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Would it matter if the speakers were 8 Ohm?
It will reduce the impact some (even though I didn't test it). But note that vast majority of speakers I have tested are around 4 ohms.
 

ocinn

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Likely a stupid question, but on the off chance the VU meters are voltage based and not current based, would splitting the outputs of your amplifier, and sending the Douk it’s own line with nothing connected to the meter’s outputs have any major issues? You’d think that would negate most technical detriments for placing it as an in-line unit?

Obviously if the meters are current based it wouldn’t work. But just a random thought.
 

ocinn

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It would have been better if an USB or AES or Toslink digital input was added to measure the absolute level.
In addition, if you can show the LUFS level, it will be more useful.
I use a TC Electronic Clarity M Stereo for this purpose. Unbelievably cheap for what is, with huge flexibility. Can accept all spdif formats (toslink, rca coax, aes, bnc) and usb (only for in DAW work w/ plug-in.). Also 0db is actually 0db, since it’s digital.
 
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amirm

amirm

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Likely a stupid question, but on the off chance the VU meters are voltage based and not current based, would splitting the outputs of your amplifier, and sending the Douk it’s own line with nothing connected to the meter’s outputs have any major issues? You’d think that would negate most technical detriments for placing it as an in-line unit?
It probably has a large attenuator in front of it. If so, line level will not be able to move the meters. There is that gain though so maybe it can be compensated for a bit.
 

Feargal

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Different speaker connection types and their likelihood of a reliable connection could be an interesting thing to test.
 
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Talisman

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@amirm have you tried the switches between speakers/amplifiers? They work well?

thanks for the review
 
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amirm

amirm

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@amirm have you tried the switches between speakers/amplifiers? They work well?
I did not. Was already frustrated having to make new cables and such to do more testing. :)
 

solderdude

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Likely a stupid question, but on the off chance the VU meters are voltage based and not current based, would splitting the outputs of your amplifier, and sending the Douk it’s own line with nothing connected to the meter’s outputs have any major issues? You’d think that would negate most technical detriments for placing it as an in-line unit?

Obviously if the meters are current based it wouldn’t work. But just a random thought.
Not a stupid question at all.
As the meter is active (requires an external voltage) it could have a high load impedance and have no impact on the amp. External power could also only be needed for the background light, peak LED and relays but it would be silly to not use it for the meter circuit.
IF the found difference is indeed cable resistance (or throughput resistance as it also a switch box) then the distortion seen could well happen with smaller diameter cables or any other switch in series.

Connecting the speakers directly to the amp and plugging in (thin) cables in parallel will then certainly not affect the sound.

Would be interesting if the load resistance is measured of the device (so no speakers or amps connected)
 
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amirm

amirm

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Connecting the speakers directly to the amp and plugging in (thin) cables in parallel will then certainly not affect the sound.
For some reason I didn't think of this even though that was the case with their line level products. :) Will see if I have time tomorrow to test it this way.
 

Laniciffo

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Might be the best use of the 'B' speaker outputs of so many integrated amplifiers ?
 

Talisman

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If you select A+B on the amp, then the result is the same. If you select A alone, then B is not playing anything so would not work.
I believe it refers to the fact that many inexpensive integrated amplifiers have only one pair of outputs and not two. With this they can have the "pair B"
 
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