Douk VU3 VU Meter Review (Updated Version)

[AdamG]

No hint which one it is?

Ask Rick he is in contact with Amir to determine what model. If at all. I understood that you were involved with this as well. I just made the announcement about possible additional model testing. I am not involved any further that that. Contact Rick for additional information.

 

[Rick Sykora]

Ask Rick he is in contact with Amir to determine what model. If at all. I understood that you were involved with this as well. I just made the announcement about possible additional model testing. I am not involved any further that that. Contact Rick for additional information.

Was pondering the Douk VU4, but do not really need 4 meters. It does look more promising as it functions only as a meter and has balanced connections. Otoh, the max line voltage appears to be 2.5V and so is lower than I would prefer.

Circling back to the VU2. If they have fixed, I think Douk should send an updated unit to Amir. Their track record is pretty poor at this point they need to show some initiative imo.

 

[KEFCarver]

My McIntosh MC275 hated (destructive type) being unloaded. The MC275 (KT88 tubes) did not even like an A/B speaker selector box inline (Adcom GFS-3), because the GFS-3 was a 'break-before-make' switch. I ended up building a 8"x11" heat-sink plate, with those old Bournes 100W (8-ohm) dummy-loads, but I never looked to solve the intermittent no-load issue, due to complexity...

Picture above shows (possibly) a wire-wound resistor that may have issues; if inductive [?].

For what it is worth, I did an A/B between a pair of McIntosh MacKit 30 monoblocks (tube) and a Bryston 2B-LP (solid state), just last week using an A/B switcher that I posted a review on ASR (search for NJ&FXAUDIO PW-6, if interested). That switcher does not apply any loading to the the unloaded amp, and both amps went through the testing without any problems or smoke

 

[JakeK]

At least both amps go through the same "noise" box when compared. lol Not really, since it's not even audible, but you get it.

Exactly that!

 

[solderdude]

For what it is worth, I did an A/B between a pair of McIntosh MacKit 30 monoblocks (tube) and a Bryston 2B-LP (solid state), just last week using an A/B switcher that I posted a review on ASR (search for NJ&FXAUDIO PW-6, if interested). That switcher does not apply any loading to the the unloaded amp, and both amps went through the testing without any problems or smoke

Only on very rare occasions with some specific (mostly tube) amps or transformer output amps not loading an amp that works near maximum output level could pose a problem.
99.9something % of the amps having an amp not loaded is not an issue.
The 390 ohm 'load' isn't really a load at all.
It is more of a gimmick (the 390 ohm resistor) than something else.
Given the change-over contacts of the used relay the 'no load' protection was easy to implement and looks nice in the description.

 

[JakeK]

Only on very rare occasions with some specific (mostly tube) amps or transformer output amps not loading an amp that works near maximum output level could pose a problem.
99.9something % of the amps having an amp not loaded is not an issue.
The 390 ohm 'load' isn't really a load at all.
It is more of a gimmick (the 390 ohm resistor) than something else.
Given the change-over contacts of the used relay the 'no load' protection was easy to implement and looks nice in the description.

While I was a/b testing amps switched using a Beresford switch the only amp that had a problem was an Onkyo AVR. All it did was shut itself down a couple of times out of many. The first time I did worry that it had blown something but it must be a circuit that protects against damaged cables etc..

 

[solderdude]

Did it switch off when disconnecting the speakers or while connecting.
Regular amps usually don't mind playing without a load.

 

[JakeK]

Did it switch off when disconnecting the speakers or while connecting.
Regular amps usually don't mind playing without a load.

It was while switching between amps. I believe the amp is briefly disconnected when this happens.

 

[solderdude]

Might be a capacitive thing in that case. The cable capacitance between the amp and switch and or mechanical switching may have generated spikes.

 

[Ap007nyc]

What would you recommend for A/B switch box (2 amps and 2 speakers) that preserves high signal fidelity (with or without remote control) without swinging needles?

 

[KEFCarver]

What would you recommend for A/B switch box (2 amps and 2 speakers) that preserves high signal fidelity (with or without remote control) without swinging needles?

I would recommend this- I have used it for either speakers or amps and it has a remote control and does a pretty good job with signal fidelity (IMHO)

Technical Review of the NJ&FX AUDIO PW-6 “HiFi Audio Power Switcher” (A/B switch)

This is a review of the NJ&FXAUDIO PW-6 “HiFi Audio Power Switcher”. I had been looking for an A/B speaker/amplifier switcher and really liked the Douk VU3 “Little Bear”, which I purchased. I was happy with until I tested it and discovered that it had a +1dB boost in the frequency response at...

www.audiosciencereview.com

 

[Ap007nyc]

I would recommend this- I have used it for either speakers or amps and it has a remote control and does a pretty good job with signal fidelity (IMHO)

Technical Review of the NJ&FX AUDIO PW-6 “HiFi Audio Power Switcher” (A/B switch)

This is a review of the NJ&FXAUDIO PW-6 “HiFi Audio Power Switcher”. I had been looking for an A/B speaker/amplifier switcher and really liked the Douk VU3 “Little Bear”, which I purchased. I was happy with until I tested it and discovered that it had a +1dB boost in the frequency response at...

www.audiosciencereview.com

Thank you for the recommendation and the detailed review. I prefer a device connecting 2 amplifiers AND 2 (or more ) speakers at the same time.

 

[KEFCarver]

You are welcome. This will do what you need, but is very pricey:

ABX Switch Comparator

Due to high demand we have produced another run of our ABX Switch Comparator. This unit allows seamless switching of up to two preamplifiers, two power amplifiers, and three sets of speakers either with or without subwoofers. The AVA ABX Switch can be used to evaluate cables and component parts...

avahifi.com

 

[solderdude]

https://www.outdoorspeakerdepot.com...e-automatic-speaker-selector-remote-atm7.html (no needles)

I am quite certain all these kinds of speaker/source selectors will add a tiny bit of extra distortion that can be measured with high SINAD amps and an AP measurement devices.
Not going to be audible when using music though. The impact the added relay contacts and binding posts combined with low impedance speakers is unavoidable.

I would not worry about it, not even using the VU3. The VU3 simply is not valuable as a measurement device in an absolute sense. It is accurate enough for comparative measurements withing 0.5dB or so.

 

[Whitecanhifi]

This degrades the sound of speakers and amplifiers? So basically, you’re telling us that since this is in his testing sound system, all of Cheap Audioman’s reviews are worthless.

 

[solderdude]

It degrades measured signal fidelity not the sound.
2 different things.

 

[pseudoid]

It degrades measured signal fidelity not the sound.
2 different things.

Great distinction to keep in mind... but neither 'lives' in isolation of the other! That is also worth remembering, though.

 

[solderdude]

Yep, at some point when signal fidelity is compromised way too much it affects the sound.
Fortunately for users of this device this is not the case as the added distortion is below any audible levels.

 

[Dougey_Jones]

Question.

I've been looking for an easy way to switch between using my RZ50's built in amps for the front three channels and my Pass Labs X5. As neither of my amps exceed -100db SINAD, would I lose anything by using a pair of these as amp selectors?

Could the performance be improved by replacing any of the internal components or wiring of these selectors with higher quality parts/wire?

 

[solderdude]

Question.

I've been looking for an easy way to switch between using my RZ50's built in amps for the front three channels and my Pass Labs X5. As neither of my amps exceed -100db SINAD, would I lose anything by using a pair of these as amp selectors?

I don't think you will.

Could the performance be improved by replacing any of the internal components or wiring of these selectors with higher quality parts/wire?

You could 'improve' the signal fidelity by bypassing the speaker selector relays (or the amp selector relays) and disconnecting the meter circuit.
Personally I would not bother and either use it as it is or not use it at all when one is worried about incredibly small and inconsequential amounts of distortion.

It would be cheaper to just use a decent speaker switch. It would not have a remote control and swinging needles. When one is worried about something that is measurable but inaudible.