Luxman AS-50R Speaker Selector Review

[DrCWO]

4 volts is 4 watts output into 4 ohm. So it is speaker levels. More output is not going to make a difference to a relay switching connections.

Did you terminate the outputs with 4Ohm? Otherwise I expect parasitic effects as it is built for low impedance.

 

[Cogito]

I'd love to have this, but at $400 I'll pass. $250 or lower, I'd order it right now. But hey, it's a Luxman afterall...

 

[Rja4000]

What about the idea to use it in reverse in order to compare level matched power amplifiers on the same pair of speakers ?

I found here a Japanese version of the manual.
Translated one of the pictures in DeepL, I got this

 

[GXAlan]

The fact it has "common" terminals means it may or may or may not switch the colds as well as the hots. Fine for common ground amplifiers, but not for bridged (BTL) amplifiers. BTL amplifiers cannot be tied at a 0V/common between L/R channels.

I found here a Japanese version of the manual.

At the bottom of the Japanese webpage, it says

Switching	3 system switching by large speaker relay ((+),(-) signal switching: BTL output amplifier compatible)

It is a Luxman not an Amazon Basics switcher . I think this is one of the reasons why companies like Accuphase and Luxman remain well respected. A lot of their gear is well designed. Even the so called Alpine/Luxman budget era seems to be generally well designed from a reliability standpoint.

The other nice thing is that, the U.S. catalog says that it is rated for 5A of current which is more power than the generic stuff can handle.

I used this to rapid a/b switch between speakers when doing some testing. It obviously doesn’t control volume differences but it’s still better than manual switching and you can have someone randomize the speaker connected to the specific letter.

The remote works pretty well and you don’t need to aim it exactly at the sensor.

This is mine, and I can pop off the cover and take some photos of the internals if there are none on the net.

 

[Hayabusa]

4 volts is 4 watts output into 4 ohm. So it is speaker levels. More output is not going to make a difference to a relay switching connections.

but not speaker currents

 

[pseudoid]

Thank you @amirm and thanks to the member sending this in for testing.
Am I the only one to think that this Luxman switch-box is probably the cheapest audio hardware Luxman has ever sold... even before equalizing for 1970s' dollars?

 

[kklarqvist]

This is a review and detailed measurements of the Luxman AS-50R speaker selector with remote control. It is on kind loan from a member and costs US $400 (discontinued?).

@amirm What load (and source) impedances were used to simulate speakers during the measurements?

 

[amirm]

but not speaker currents

Current doesn't change the measurements.

 

[amirm]

@amirm What load (and source) impedances were used to simulate speakers during the measurements?

It is a relay contact. What do you want simulated???

 

[kklarqvist]

It is a relay contact. What do you want simulated???

Physical simulation (not numeric). You may have more than one cross-talk mechanism, "capacitive","inductive", "inductive ground bounce" "resistive ground bounce". The first one is voltage (slew rate) dependent the others current dependent. Depending on your source and load impedance you will get different mix between the cross-talk mechanisms. It may be the case that some of the mechanisms are negligible an just one is dominant. This is for a speaker application ideally a standard speaker, and a standard amplifier should be connected to model the performance, but we can simulate those with resistor loads...

 

[GXAlan]

It is a relay contact. What do you want simulated???

+1

@kklarqvist
I will open the unit when I get it back and people can analyze the layout.

The big risk is the universal voltage AC adapter which looks pretty cheap, but apparently doesn’t leak much. The second risk is the IR receiver which is always active and sloppy circuitry could also add leakage.

You also have to make sure it isn’t like this

LYNEPAUDIO B049 Audio Switcher Review

This is a review and detailed measurements of the LYNEPAUDIO B049, 6 input, 4 output active audio switcher. Unfortunately I can't find who sent it to me but it costs US $44.85 It is nice, solid case with an input selector that feels pretty good. The output switches are a bit mushy and hard to...

www.audiosciencereview.com

Or

Douk VU3 Review (VU Meters)

This is a review and detailed measurements of the Douk / Little Bear VU3 dual analog VU meter and 2-way amplifier/speaker switcher. It is kindly sent to me by testing by a special member. VU3 costs US $140 from Amazon including Prime shipping. The VU meter are the "paper back" ones which I...

audiosciencereview.com

 

[amirm]

The first one is voltage (slew rate) dependent the others current dependent.

Slew rate due to a relay contact? Ever see that in a relay spec?

Depending on your source and load impedance you will get different mix between the cross-talk mechanisms.

The mechanism is the mechanism. It doesn't depend on what is outside it.

This is for a speaker application ideally a standard speaker, and a standard amplifier should be connected to model the performance, but we can simulate those with resistor loads...

My analyzer is not capable of sinking into 4 ohm load. You would have to use a power amplifier to do that which degrades performance substantially relative to my analyzer. The amp will have its own crosstalk, noise and distortion.

 

[pseudoid]

I'd pay 15 "Likes" to any member just to see the internals of this relay I/O switch; because it makes no sense (to me) that "System C" Output would have the least amount cross-talk out of the 3 outputs...by around 6dB.

Worst case crosstalk is -55 dB but gets better if you select C or none.

Does "none" mean all relays are open (mute)?

 

[restorer-john]

I'd pay 15 "Likes" to any member just to see the internals of this relay I/O switch; because it makes no sense (to me) that "System C" Output would have the least amount cross-talk out of the 3 outputs...by around 6dB.

Simple answer.

Speakers A and B are likely just sets of contacts on one 4PDT relay.

Speakers C are likely on a totally separate 4PDT relay.

Amir's "crosstalk" measurement on this loudspeaker switcher is completely botched.

These are the types of relays used in similar products (from my relay drawer):

Notice the contacts, their proximity to one another and when combined with the high impedance analyzer input you are seeing the fictitious crosstalk plot that has no relevance to loudspeaker level signals and loads, or the use-case.

 

[pma]

Your crosstalk measurment is not applicable to speaker levels as there is no load. The input to the analyzer is 100/200k and you are simply "measuring" capacitive coupling crosstalk unloaded.

Exactly. The measurement used is a nonsense.

 

[TimoJ]

My analyzer is not capable of sinking into 4 ohm load. You would have to use a power amplifier to do that which degrades performance substantially relative to my analyzer. The amp will have its own crosstalk, noise and distortion.

Yes, but you could use a high quality amplifier and compare measurements send directly to speaker dummy load vs. thru the speaker selector. That would reveal real life performance of the selector.
I mean, you have measured extra distortion that was caused by (Buckeye) amplifier's internal speaker connections. So the same could happen also with speaker switches.

 

[Hayabusa]

Current doesn't change the measurements.

Proper source and load impedance would surely make a difference.
Cross-talk would be less, and probably the 60Hz peak would disappear.
If the internal resistance is not low enough there would be FR fluctuation with a simulated complex load.

 

[anphex]

Isn't this just a big remote controlled array of relays?

 

[Punchy_Power_Cat]

"Peel-coat circuit boards are used for the main audio signal path, eliminating the negative effects of the coating film that can adversely affect sound quality. Unique attention has been paid to every detail, such as the beeline construction, which configures circuits to take the shortest route possible, and a non-angled wiring pattern for smooth signal transmission."

This is not on the AS50, but another Luxmann top tier amp. I wonder if smoothened curves instead of sharp angles as conducting-lines imprinted in a circuit board does a difference to sound quality. This sound like snakeoil salesmanship to me.

 

[martin900]

Can any of the owners share some pictures of the internals? There are none to be found on the interwebz.