Douk VU3 Review (VU Meters)

[Kimbrough Xu]

that's right - 2 in and 1 out or vice versa

I've gone down quite a rabbit-hole in terms of checking out what is available on the market for these switchers (short of building one myself), and settled on this one:

LINEPAUDIO 2 in 4 Out Speaker Selector Switch Box 4 Zone Amplifier and Speaker Selector with Volume Control Banana Jack 6.5mm Earphone Jack : Amazon.com.au: Electronics

LINEPAUDIO 2 in 4 Out Speaker Selector Switch Box 4 Zone Amplifier and Speaker Selector with Volume Control Banana Jack 6.5mm Earphone Jack : Amazon.com.au: Electronics

amzn.asia

Allows for a lot of flexibility on the amp/speakers and also as a headphone monitoring socket, which I assume is wired by way of a simple resistor array. I'll report back once received and tested.

So with the heaphone output I guess you use it for testing speakers?

 

[KEFCarver]

that's right - 2 in and 1 out or vice versa

I've gone down quite a rabbit-hole in terms of checking out what is available on the market for these switchers (short of building one myself), and settled on this one:

LINEPAUDIO 2 in 4 Out Speaker Selector Switch Box 4 Zone Amplifier and Speaker Selector with Volume Control Banana Jack 6.5mm Earphone Jack : Amazon.com.au: Electronics

LINEPAUDIO 2 in 4 Out Speaker Selector Switch Box 4 Zone Amplifier and Speaker Selector with Volume Control Banana Jack 6.5mm Earphone Jack : Amazon.com.au: Electronics

amzn.asia

Allows for a lot of flexibility on the amp/speakers and also as a headphone monitoring socket, which I assume is wired by way of a simple resistor array. I'll report back once received and tested.

Looks interesting, but only 1 amp at a time can be used, of course. Running 4 sets of speakers does not not like a good idea without having additional resistors inside, which means you probably won't be able to apply full amp power to the speaker(s)- guess it depends on what you are trying to do.

But in sometimes I would want my 2 pairs of speakers play at the same time, see 2 pairs in my 2 rooms, do you have such switcher to recommend?

Two pairs should not be a problem if they are 8ohm speakers....

 

[lordearl]

So with the heaphone output I guess you use it for testing speakers?

No it would simply be for testing or listening the amplifiers via headphones - the resistor array would reduce the output to a suitable level for headphones. I don't intend to run speakers and headphones at the same time (not until I've checked out the grounding in the circuit anyway). Eg. it will be interesting to 'hear' the noise floor of solid state versus tube amps through a set of headphones.

 

[lordearl]

Looks interesting, but only 1 amp at a time can be used, of course. Running 4 sets of speakers does not not like a good idea without having additional resistors inside, which means you probably won't be able to apply full amp power to the speaker(s)- guess it depends on what you are trying to do.

Good point - though I must say that any time I switch sources / preamps / amplifiers, I always power down the system entirely first.

When you are testing two amps @KEFCarver, do you tend to have them both on at the same time and just switch between them without turning the power off?

 

[Kimbrough Xu]

No it would simply be for testing or listening the amplifiers via headphones - the resistor array would reduce the output to a suitable level for headphones. I don't intend to run speakers and headphones at the same time (not until I've checked out the grounding in the circuit anyway). Eg. it will be interesting to 'hear' the noise floor of solid state versus tube amps through a set of headphones.

Interesting, but isn't the power of the amplifier is too much for a headphone? Or it is reduced by the switcher?

 

[knobtwiddler]

I think its a given that the meter ballistics are not going to resemble a real VU meter at all; making a meter movement which conforms to real VU meter specifications is expensive - so much so that even some 'professional' gear of the day didn't have meters which met the spec.

This really is worth repeating. From wading through this thread, the only genuine VUs I've seen mentioned are the Nishizawa that Dualazmak mentions (discontinued). To my knowledge, there are a tiny handful of firms worldwide who still make genuine VUs that have an 'obligatory' 300mS integration time (Hoyt and Simpson are two examples - well over $200 USD a piece). The meters shown on the Douk etc. would be equally at home on the front of a budget battery charger. Although you can drive them to achieve something near the 300mS spec, they will be jittery and have overshoot. Companies have been labelling consumer-grade moving coil meters as 'VU' since the '70s. In other industries, this sort of thing would be a breach of product description, as they are nothing of the sort. A bonafide VU will weigh several times that of a consumer-grade voltmeter and cost exponentially more, as you suggest.

Note that Sifam no longer claim that their meters hit the IEC spec. They moved the factory when they got taken over and the current range is very different to the ones that were made in the UK.

Here is a paper that shows genuine VUs to be anything but 'virtually useless': https://www.researchgate.net/publication/283040459_Method_to_Evaluate_the_Ballistics_of_Audio_Meters

 

[dualazmak]

From wading through this thread, the only genuine VUs I've seen mentioned are the Nishizawa that Dualazmak mentions (discontinued).

Thank you for your reminder again.
We (you and myself) have pointed this before here and here.

It is really nice that a small Japanese company SUZUDES10 still has stock of R-65 VU Meter after Nishizawa has discontinued the production.
Nishizawa R-65 VU Meter is fully compatible with IEC 60268-17 VU meter specification/standard as shared here.

As for my DIY construction of 12-VU-Meter Array using Nishizawa's R-65, please refer to my post here on my project thread.

 

[KEFCarver]

Good point - though I must say that any time I switch sources / preamps / amplifiers, I always power down the system entirely first.

When you are testing two amps @KEFCarver, do you tend to have them both on at the same time and just switch between them without turning the power off?

Sorry, I am just seeing this question now. Both amps are on at the same time, but you need to make sure that they are matched so that the same input signal into both of them gives the same power level going out of them, so that you are hearing any tonal difference between them (assuming that the amps have a decent frequency response that is similar)

 

[NoxMorbis]

Thank you for your reminder again.
We (you and myself) have pointed this before here and here.

It is really nice that a small Japanese company SUZUDES10 still has stock of R-65 VU Meter after Nishizawa has discontinued the production.
Nishizawa R-65 VU Meter is fully compatible with IEC 60268-17 VU meter specification/standard as shared here.

As for my DIY construction of 12-VU-Meter Array using Nishizawa's R-65, please refer to my post here on my project thread.

Is there any kind of kit for a VU meter? I can solder like a MFer.

 

[dualazmak]

Is there any kind of kit for a VU meter? I can solder like a MFer.

We also discussed a lot about "VU meters" and "quasi-VU meters" as well as "sham-VU meters" on the thread entitled "VU Meters: Let's See 'Em!!"

I am sorry that nowadays I can find no genuine VU meter kit compatible with IEC 60268-17 VU meter specification/standard except for the Nishizawa R-65 (discontinued) and its kits from SUZUDES10 in Japan (please refer to my post here and here on my thread), especially transient ballistic behaviors of rise time, overshoot and fall time;
The rise time, defined as the time it takes for the needle to reach 99% of the distance to 0 VU when the VU-meter is submitted to a signal that steps from 0 to a level that reads 0 VU, is 300 ms. The overshoot must be within 1 to 1.5%. The fall time is the same as the rise time, 300 ms.

 

[NoxMorbis]

We also discussed a lot about "VU meters" and "quasi-VU meters" as well as "sham-VU meters" on the thread entitled "VU Meters: Let's See 'Em!!"

I am sorry that nowadays I can find no genuine VU meter kit compatible with IEC 60268-17 VU meter specification/standard except for the Nishizawa R-65 (discontinued) and its kits from SUZUDES10 in Japan (please refer to my post here and here on my thread), especially transient ballistic behaviors of rise time, overshoot and fall time;
The rise time, defined as the time it takes for the needle to reach 99% of the distance to 0 VU when the VU-meter is submitted to a signal that steps from 0 to a level that reads 0 VU, is 300 ms. The overshoot must be within 1 to 1.5%. The fall time is the same as the rise time, 300 ms.

How aobut a spectrum analyzer? That would be more for eye candy, but still can't find anything worth crap.

 

[dualazmak]

How aobut a spectrum analyzer? That would be more for eye candy, but still can't find anything worth crap.

I use software DSP EKIO on my audio dedicated PC which shows cross-overed gains of all the channels by its vertical gain meter on my PC monitor screen.

I mainly use JRiver Media Center as my audio (& visual) play center which has audio spectrum indicator also on my PC monitor screen, if I would like to show it; I actually do not like the design of the spectrum analyzer/indicator of JRiver and usually do not use it.

You would please understand my personal nostalgic preference (please refer to here and here) for traditional physical genuine large glass-face VU meter(s) fully compatible with IEC 60268-17 VU meter specification/standard, and I like the DIY built 12-VU-Meter Array indicating whole-sum signal gains (L & R) and each of my 5-way 10-channel SP driver gains using all the same 12 large glass-face 2700K LED illuminated VU meters...

 

[NoxMorbis]

I use software DSP EKIO on my audio dedicated PC which shows cross-overed gains of all the channels by its vertical gain meter on my PC monitor screen.

I mainly use JRiver Media Center as my audio (& visual) play center which has audio spectrum indicator also on my PC monitor screen, if I would like to show it; I actually do not like the design of the spectrum analyzer/indicator of JRiver and usually do not use it.

I use MusicBee for music, and it has some decent built in "analyzers" (and 100s of other user options/skins/configutrations you can go WAY down the rabbit hole with, etc). However, I was talking about a hardware spectrum analyzer, like the old school type, in kit form, preferably with an enclosure. I guess those type of things are just so NOT in demand it's not worth doing them. I think it would be cool for Aiyima, Douk etc. to offer kit forms of their amplifiers, where you do the assembly/soldering, if it was a good price reduction. It would allow the satisfaction of DIY and replacing specific components for upgraded specifics to our liking.

\

I was also considering this from Douk, not for accuracy, but just asthetics, but now I'm unsure becasue of added distortion in the unit tested here. This isn't a switch box, though, just a pass through, but still. . . .

Douk Audio VU22 Dual Analog VU Meter Display DB Panel MIC+LINE Sound Level Meter

 

[dualazmak]

As you can find in my specific post on 12-VU-Meter Array, I strictly dare do not use the through-out signals from VU meter for further audio listening purpose. In my case, all the VU meters should be placed at the end of the signal chain so that they should have absolutely no effect on sound quality in my audio system.

I hope you would please read very carefully, especially the concept and policy in my DIY, in the specific post on my 12-VU-Meter Array.

 

[NoxMorbis]

As you can find in my specific post on 12-VU-Meter Array, I strictly dare do not use the through-out signals from VU meter for further audio listening purpose. In my case, all the VU meters should be placed at the end of the signal chain so that they should have absolutely no effect on sound quality in my audio system.

I hope would please read very carefully, especially the concept and policy in my DIY, in the specific post on my 12-VU-Meter Array.

I don't know what to say. You're amazing. Far above anything I can even imagine. Stellar, exceptional, unique, amazing skills.

 

[Doodski]

I don't know what to say. You're amazing. Far above anything I can even imagine. Stellar, exceptional, unique, amazing skills.

@dualazmak is a accomplished medical scientist I think it is with published papers and worked on covid research stuff. Very upper level stuff I think it is. Perhaps @dualazmak can chime in and clarify this a little for us.

 

[NoxMorbis]

@dualazmak is a accomplished medical scientist I think it is with published papers and worked on covid research stuff. Very upper level stuff I think it is. Perhaps @dualazmak can chime in and clarify this a little for us.

I've always thought life would be so much more interestiong and joy filled if I had more brains. I think I am right.

 

[dualazmak]

@dualazmak is a accomplished medical scientist I think it is with published papers and worked on covid research stuff. Very upper level stuff I think it is. Perhaps @dualazmak can chime in and clarify this a little for us.

Thank you for your kind words.

I am not an MD (medical-doctor/physician), but I am a Ph.D. scientist specialized in pharmaceutical sciences, molecular imaging, radiopharmaceuticals, medical imaging technologies, etc.

I have already semi-retired from academic and industry activities; now I am an independent medical/healthcare consultant which means I have fairly nice time for enjoyments in audio system setup and music listening, mainly classical and early classical music and limited area of jazz (rather smooth jazz trio). Please refer to here for my music preferences and reference music tracks.

You can find here and here Hyperlink Index for my project thread.

If you would be interested in early classical music, please visit my another thread entitled "Lute Music and Other Early Music: Stunning Recordings We Love".

​

 

[NoxMorbis]

@tomchr, any chance you would take a shot at designing a proper one of these and able able to sell it near these prices? I will go up to $199 if it works well.

I wrote Douk about the noise on the VU3 today and asked if they would update the unit and noise problem and when. They replied with this:

"Hello Our technicians got back to us quickly. The post [this review] is two years ago. It is our first version of VU3 and did have this issue. VU3 has been updated for several times in these years. We added a filter circuit into it and this issue had been fixed. Best Regards Yours Douk Audio

 

[NoxMorbis]

The Douk is not meant as a measurement device. There is no calibration. It is just meant to see a meter jump somewhat up and down in the rhythm of the music.

The problem with meters on outputs of amps is that they can only measure the output voltage.
When they must say something about the power (and have a scale stating power) one would also have to measure current without resorting to a low resistance in series so a current probe.
With both current and voltage one can create a 'power' scale independent of the speaker impedance.

Then rises another issue.. the scale... for it to be really meaningful the meter would need to have a log scale (over many dB) unlike the Douk meters that are actually linear scale.

Then there is yet another issue IF one not just wants a needle or LED jumping up and down but have useful info.
Does one want to know actual (very short) peak power (to check for clipping levels) or average power shown (using a needle) or does one want a digital meter that can show both peak and average levels, weighted or not etc.

Creating a meter that really says something thus isn't as easy as a meter jumping up and down and really saying nothing. The latter is what most want... bling.

For that... just buy this Douk thing and connect the meter in parallel to the speakers and be done with it.

I wonder why Douk didn't do that initially and avoid the noise problem altogether?