Douk Audio VU2PRO Needs Your Opinions!--The Upgraded Version of Douk Audio VU2.

[Douk Audio]

Hello all ASR members,

Our VU2 RCA input selector with VU meters released in 2020, it's been over 4 years now. We are happy that many people have seen it and liked it, and we also received many suggestions.

Recently, our product department is going to update it in the appearance, size (will be larger and the same as our VU3PRO) and the functions..
Based on most feedback and suggestions from our users of the VU2, now we have two solutions.

Option A
Audio source: built-in MIC pickup, XLR*1, RCA*3, SPDIF*1
Working mode:
RCA--3-IN-1-OUT / 1-IN-3-OUT
XLR--1-IN-1-OUT
SPDIF--1-IN-1-OUT

Option B
Audio source: built-in MIC pickup, RCA*4, SPDIF*1
Working mode:
RCA--4-IN-1-OUT / 1-IN-4-OUT
SPDIF--1-IN-1-OUT

Note:
RCA, XLR and optical fiber are parallel input and output. No audio signal conversion function. In other words, the RCA output will only work when there is RCA input; the XLR output will only work when there is XLR input; the optical output will only work when there is optical input.

Introduction
3 knobs: adjust color, GAIN and sensitivity.The GAIN adjustment is only useful for the VU meter swing range and will not affect the sound quality.
Buttons:
The left one is to switch audio source among MIC, RCA, XLR (optional) and optical fiber.
The right 3 or 4 buttons are to switch RCA input or output.

Other Parameters:
Response frequency: 30Hz-20KHz
Backlight brightness adjustment: support (5 levels, can be turned off)
Backlight color adjustment: support (35 colors/marquee color)
VU meter gain adjustment: support (20 levels)
VU meter sensitivity adjustment: support (30 levels)
Remote control: support
RCA mute function: support
Settings saved after shutdown: support
Power interface: USB (Type-C)

The difference between the two options are with or without XLR input and output, please let me know your choice. Of course, other suggestions are also welcome! Thank you all!

 

[solderdude]

How can +6dB be 300W (if 0dB is 100W) ?
It should say 400W or ...300W should be +5dB on the scale instead of +6.

 

[GXAlan]

At least among the ASR crowd, I think there would be a preference for a calibrated meter.

Besides looking cool, you could use it to calibrate two sources that you are looking to A-B compare. For line level devices, you basically just need to let people calibrate to 2V or 4V (as 0 dB) and then have the ability to go below or above if you just wanted to change the visuals.

Take a look at what the McIntosh MPM4000 goes for on eBay. That has zero switching.

As we move to DAC into active speakers, I think an interesting product would be a simple pass through with 120 dB SINAD that has a calibrated meter so we can visually see what is being fed to the speakers. Both McIntosh and Accuphase mask the bottom of the display so that the linear scale is centered.

 

[Blumlein 88]

How can +6dB be 300W (if 0dB is 100W) ?
It should say 400W or ...300W should be +5dB on the scale instead of +6.

Maybe those are metric dB?

Or that is a nogarithmic scale.

PS the 1.2 mW is wrong too.

 

[Douk Audio]

How can +6dB be 300W (if 0dB is 100W) ?
It should say 400W or ...300W should be +5dB on the scale instead of +6.

Hi, thank you for pointing out this. The picture is rendering, not a real one. The actual dial only displays db, not power.
You may refer to this

 

[MaxwellsEq]

VU meters are pretty useless.

Have you considered PPM ballistics with fast rise, no overshoot and slow decay. There would obviously be less of the valueless "flapping about" that VUs show (which might disappoint people who think meters should flap about a lot) but PPM would make the meters potentially useful.

 

[Talisman]

VU meters are pretty useless.

Are they useless?
Of course

Do I like having them and looking at them?
You bet!

 

[solderdude]

Hi, thank you for pointing out this. The picture is rendering, not a real one. The actual dial only displays db, not power.
You may refer to this
View attachment 402445

too bad the dB scale is not from -60 to 6 but rather the linear scale.
Peak or RMS, slow or fast ?
The calibrate function is handy but troublesome at the same time if accuracy is the goal, fine for moving needles.
Does it also convert rca to xlr and vice versa ?
Is the DAC output (toslink) available on the RCA / XLR ?

 

[Douk Audio]

too bad the dB scale is not from -60 to 6 but rather the linear scale.
Peak or RMS, slow or fast ?
The calibrate function is handy but troublesome at the same time if accuracy is the goal, fine for moving needles.
Does it also convert rca to xlr and vice versa ?
Is the DAC output (toslink) available on the RCA / XLR ?

Hi, our engineer replied that we can set the db scable from -40db to +6dB. And the VU2pro can support two modes, PeaK and RMS(VU) mode. Please refer to the below picture.

Since we want to minimize the impact on the audio signal, the VU2pro without audio signal conversion function. The three audio signals cannot be converted to each other.

 

[Douk Audio]

VU meters are pretty useless.

Have you considered PPM ballistics with fast rise, no overshoot and slow decay. There would obviously be less of the valueless "flapping about" that VUs show (which might disappoint people who think meters should flap about a lot) but PPM would make the meters potentially useful.

Thank you for your suggestions, I will collect it and convey to our PD.

 

[Blumlein 88]

Thank you for your suggestions, I will collect it and convey to our PD.

Please consider MaxwellsEQ suggestion. A Peak Program Meter would be truly useful and still move about in a way that to me is more interesting than the old VU action. Also for an uncommon feature in consumer meters maybe adding a mid side mode. One meter is the mid or mono value and the other is the side signal.

 

[antcollinet]

The actual dial only displays db, not power.

I was just going to suggest this. It makes no sense to have a specific power rating. The power will vary totally from system to system.

However, I much prefer the look of the horizontal gauge in the renderings compared to the curved guage of the actual meter you show.

I would also only buy one of these if it had at least one balanced IO. It could be TRS instead of XLR if that helped on costs.

 

[restorer-john]

@Douk Audio Just look at any vintage Japanese power amplifiers with proper calibrated power meters made all through the 1970s and 1980s for masterclass examples on how to layout and drive an analogue power meter.

Even better, pull the schematics and copy the drive circuitry. Most of the drive ICs are still available. Get somebody with a modicum of skill to build you some high sensitivity meter movements.

Make something useful, not just another useless box with no purpose.

 

[restorer-john]

I was just going to suggest this. It makes no sense to have a specific power rating. The power will vary totally from system to system.

No. Power is fine. It's all just voltage based anyway.

Pick one or even two impedance scales. High and low ranges.

40VRMS is 0dB/200W@8R or 400W@4R
Have up to +5dB for genuine peaks, a +3dB for double (peak) with a fast metering and hold. We are talking capturing a 10kHz peak accurately with not too much overshoot.

 

[antcollinet]

No. Power is fine. It's all just voltage based anyway.

Pick one or even two impedance scales. High and low ranges.

40VRMS is 0dB/200W@8R or 400W@4R
Have up to +5dB for genuine peaks, a +3dB for double (peak) with a fast metering and hold. We are talking capturing a 10kHz peak accurately with not too much overshoot.

Right, but then you'd (or at least I'd) ideally want 0dB to be rated a similar power to your amp. If it showed 50W at 0dB that might suite amplification from 25 to 100W. But if your amp were rated 300W you'd want a different scale. And vice versa. This is (presumably) what you'd get on the VU meters on an old school amp.

And personally I'd either want the scale to match my amp power (with my speaker impedance) precisely. Or I'd want 0dB to represent my maximum listening level, whatever power that happened to be. I'd be much happier with the meter just showing DB, so I can set the reference level as anything I like.

 

[solderdude]

Its not going to be a power meter (there is no power scale)

Just a VU meter (swinging needles) for sources or amp inputs.

The mic is a bit baffling as it would not measure anything other than something to make needles swing.

The calibration part for TOSLINK is easy and should be fixed at 0dB FS on 0dB. Won't ever use the 'red' part though if showing true peak levels but could when showing rms levels.

For the device to be meaningful as a measurement tool it should either be calibrated at a known voltage (say 0dBV = 1V) but then +6dB would be 2V max.
Or say 2V = 0dB (allowing 4V on RCA in as +6dB) and span the entire audible range.
As it appears now it is NOT a measurement device at all as 0dB can be anything (any voltage depending on the position of the 'gain' knob that has no scale) and the mic function does not measure something valuable either and there would have to be some explanation how to calibrate (if it is going to serve a purpose other than swinging needles)

It is clearly just 'for fun' and should be marketed as such... nice looking swinging needles.

 

[Jeromeof]

Its not going to be a power meter (there is no power scale)

Just a VU meter (swinging needles) for sources or amp inputs.

It is clearly just 'for fun' and should be marketed as such... nice looking swinging needles.

I think anything with swinging needles is just for fun and could not really be used for "measurements". And while a bit "dumb" I think the mic input would suit many people - as it you would get the swinging needles but you could keep this device away from the signal path and therefore no worries about added distortion to the signal.

 

[restorer-john]

I think anything with swinging needles is just for fun and could not really be used for "measurements". And while a bit "dumb" I think the mic input would suit many people - as it you would get the swinging needles but you could keep this device away from the signal path and therefore no worries about added distortion to the signal.

Well they might as well put RGB LEDs under plastic lenses to light up the roof in time to the music too.

Douk Audio wants our opinions. It's a completely useless product as it stands in every regard and I wouldn't want one even if it was free.

Meters are for measurement, not entertainment.

 

[amirm]

The mic is a bit baffling as it would not measure anything other than something to make needles swing.

I like the mic option for no-impact, no-wiring visualization fun.

 

[restorer-john]

I like the mic option for no-impact, no-wiring visualization fun.

I dare you to put one in your main system.