Douk Audio VU3 Pro Analog VU Meter - more bling! (Make sure to try some harder music at audio shows! 😉)

Hey there guys and gals, since I've been in the mood for bling this end-of-year season (as per recent discussion of the Fosi Audio LC30), let's grab another one of these VU meter boxes - as you can see above, it's the Douk Audio VU30 Pro (typically around US$150, Canada link, AliExpress), a 2024 upgraded version of the Douk Audio VU3 (non-Pro) which came out back in 2021.

Similar to the Fosi LC30, this is also an analog meter with 2-in/2-out switcher which will allow you to select one of two amplifiers and two speakers. As a "Pro" model however, this box has been upgraded with a few funky features over the first version which we'll talk about.

As usual, I bought this from standard retail channels; no contact with the manufacturer.

First, here's a peek at the cardboard box and included accessories:

In the box we have the Douk Audio meter/switcher, the plastic remote control (2 AAA batteries not included), a 5V/2A USB adaptor, and a short ~4' generic run of USB-A to USB-C cable. There's of course some perfunctory pamphlet/manual and a warranty card.

Here is the box itself; notice that the edges are more squared than the curved Fosi LC30 stacked on top for comparison:

It's clear the moment I held each in the hand, the Fosi LC30 simply is a better made physical box. While smaller (but slightly taller), the LC30 feels more solid than the Douk VU3 Pro, both weighing about the same ~3.5lbs. The Douk VU3 Pro's dimensions are 10.6" W x 2.95" H x 7.5" D (depth including the binding posts and front knobs sticking out). The VU meter window is a little more spacious with the Douk VU3 Pro (about 3.75" diagonally, an extra +0.25" diagonally over the Fosi), the meter and markings are about the same size on both units.

Notice that the meter dB/Watt scales are different at least for the portion below 0dB between the two boxes. As discussed last time by SolderDude, there's clearly a problem with the scaling on the Fosi. The Douk Audio at least correlates accurately below 0dB/100W (for the most part).

On the underside, the VU3 Pro has small plastic legs which provide about 1cm clearance. I would have preferred rubberized feet that don't slide around than the plastic. Likewise, I would have preferred that the top lid didn't say "DOUK AUDIO VU3 PRO"; I prefer the more subtle esthetics of the Fosi. No text on top, and maybe just the name and model number in low contrast text bottom-left front of the unit.

Here's a closer look at the front:

Turned on with default color and brightness. Notice both Speakers 1+2 outputs turned on above, accessible with the remote control.

Unlike the Fosi LC30 where there's a single sensitivity knob to control the meter movements, this one has both gain and sensitivity settings. That's good. Maybe there's more of an opportunity to calibrate the arm swings; but to be honest, accuracy probably doesn't matter much when we're talking about bling. 🙂

The large knob on the front is now used to change color and brightness (5 levels - 0/30/50/80/100%) of the display; turn it to change color, press to change brightness. The product's ad indicates 35 LED backlight color adjustments which is cool. Here are a couple of the color options to complement your system's appearance and mood:

The bottom row of controls include a MIC/Power button which allows you to have the device "listen" to the sound in the room and have meters dance based on that instead of the amplifier input. Since there's only one mic, the meters will be mono when MIC turned on.

Then to the bottom left we have the Amplifier A/B input buttons, and on the right Speaker 1/2 output selection.

Beyond the front buttons and knobs, most feature controls are replicated with the remote which is a typical light plastic unit with functions clearly labeled. It uses 2 AAA batteries:

Most of the buttons are self-explanatory. ORG turns the display to a default orange color. Notice the "1+2" bottom button. This device allows both sets of speakers to be active at the same time. Be careful about parallel loads and low total impedance as one might imagine. As far as I can tell, this feature to turn on both speaker outputs seem to be controllable only through that remote button.

In the rear, we have the gold-plated speaker-level binding posts. They look like pretty good quality connectors. The company literature speaks of the device capable of handling 350Wpc into 4Ω maximum power (and a lower 200Wpc into 2Ω).

Power input is through the USB-C 5V port just like the Fosi LC30. I noticed that this device draws significantly more power than the Fosi based on USB meter readings.

If you use the Amp A input, current demand is about 50% lower than with Amp B. With backlighting off, if you use Amp A it starts at 0.22A and this goes up to 0.41A at 100% brightness. If you use Amp B, it starts at 0.48A with backlight off and increases to 0.66A at 100% brightness. Current utilization increases further if you turn on Speaker 1+2 such that with Amp A selected, it goes from 0.36A to 0.56A (0% and100% brightness), and Amp B 0.63A to 0.80A. So basically it runs from 1.1W to 4W compared to the tiny 0.6W maximum for the Fosi Audio. Stick with Amp A input if you want to minimize power consumption, no big deal in the big picture and the unit does not get warm in extended use.

Measurements-wise, let's do as I did with the Fosi LS30 previously and just have a look at whether this box changes the electrical parameters as viewed by the amplifier.

Again, let's use the Sony SS-CS5 (Mark 1) bookshelf speaker and Nordost-like flat cable as I did before.

As with the Fosi LC30, whether directly measured or through the Douk VU3 Pro, there's no meaningful difference. Just a tiny -0.05Ω minimal impedance change through the Douk likely due to the 510Ω load resistor they have in there.

Be careful if you have both Speaker 1+2 active of course. Parallel speaker loads will obviously drop the resistance/impedance, here's what it looks like with the Sony bookshelf connected to Speaker 1 and I shorted across Speaker 2:

There's no load protection as would be found with something like the Rotel RSS-900's "Indirect" outputs.

Local Vancouverite jazz singer Karin Plato's album This Could Be The One (2018) playing.

So how does this sound?

Yeah, the system still sounds great. Nothing to say folks other than it's simply transparent as best as I can tell. I didn't bother checking the distortion amounts and am suspicious that it's probably similar if not the same as the NEOHIPO ET30 - if anyone has both, it would be interesting to see the insides.

Comparing this Douk Audio VU3 Pro with the Fosi LC30, I prefer the Douk VU3 Pro for its extra features: selectable display color, both gain and sensitivity tuning, more accurate dB/W markings, MIC input mode might be useful, slightly larger meter windows, and simultaneous Speaker 1+2 output. But the Fosi LC30 does have some merits: IMO, the box is of higher build quality, and power utilization is lower.

Both provide enjoyable bling. ☺️

Addendum: Trying a little calibration...

While I totally accept that these meters are for fun, I could not help but try my hand at a tiny calibration effort at least. So, taking it to the workbench, sticking on an amp and dual 4Ω loads to the speaker outputs, let's see where we adjust the gain knob for 1W into 4Ω, using 1kHz sine:

BTW, I like this darker orange color as my default setting in the sound room. Nice "warm" glow when listening to digital. Makes it sound "more analogue". 😉

There ya go, although I took the picture a bit at an angle, at that 1W level, I had to turn the gain knob down to about 2 dots over the 9-o'clock position. I wonder if there are some fine-tuning pots one might be able to adjust if we open up the box to get the needles to align exactly at 1W. Given that this device isn't meant to be a calibrated instrument, the channel balance is I think absolutely fine.

The sensitivity knob looks like it just adjusts the dynamics of the movements so didn't add to the calibration process. I just left it at the default 12-o'clock.

Unfortunately the accuracy is low. For example going down -10dB doesn't exactly correlate with the meter's 0.1W indicator. Obviously this is a very rough estimate of power but it'll give a relative idea of how much the amp is being driven I suppose. With the gain knob reduced, you'll also notice the needles won't "dance" as much compared to the default 12-o'clock position. Heck, if you have very sensitive speakers in a small room, you'll barely notice movement at all. This should be no surprise since much of the time, we're probably barely feeding 1W into our speakers (measure how much power you need for yourself).

Obviously, if the needle barely moves, it's no fun, so feel free to crank up the knobs! 😁

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Let's end off with some music! Here's a jazz vocal track from Karin Plato mentioned above (she also writes jazz album reviews for TAS):

Recorded at Bryan Adams' The Warehouse Studio, here in Vancouver.

And to make your VU meters dance hard, here's Celldweller's "End Of An Empire" (2015). Dynamic range measured as DR4 stereo and DR12 multichannel/Atmos; these days, if you are playing stereo only, but have access to the multichannel version of many albums, I would recommend trying the downmix of the multichannel to stereo - then pump up the volume and see if you enjoy that more.

I don't know about the end of an empire, but it does feel a little like we're in the process of the end of something politically meaningful here in late 2025.

I dare you to request an electro-metal track like this at the next audiophile show to hear how "high-end" gear handles something a little less "polite" than the usual, with the mandatory low bass power of course.😆

[In 2019, at the last Rocky Mountain Audio Fest on Sunday afternoon as the crowds had dispersed, I requested Metallica in the Göbel+CH Precision / Bending Wave room, to be played LOUD of course (maybe I've met Elliot Goldman and didn't know it). Now that folks was an interesting experience to hear how an expensive system navigated and "articulated" some challenging music! 

Maybe try that at HIGH END Vienna in 2026. Trust me, it'll be fun. 🤯]

Finally, for the Taylor Swift fans, the "original-era" (non-Taylor's Version) albums - Taylor Swift, Fearless, Speak Now, Red, 1989, reputation - are now available as multichannel/Atmos mixes. I believe all studio albums and variants are available in multichannel/Atmos now. Plus Disney+ has all that new content this weekend for Swifties including The Eras Tour: The Final Show filmed here in Vancouver at the end of the run.

Hope you're enjoying the music (and bling), audiophiles, into year end!