Luxman AS-50R Speaker Selector Review

[amirm]

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?).

The momentary controls switch relays that literally sound high quality with a warm tick! Back panel oozes with class and yet again, quality:

Yes, made in Japan! As you see, the unit is powered so that it can switch the relays and act on remote (which I did not test).

Luxman AS-50R Speaker Selector Measurements
Let's start with our dashboard driving one channel:

There is some power supply mains leakage which at -130 dB is quite harmless. SINAD is better than just about any amplifier you hook it up to so good enough.

Frequency response is dead flat as expected:

For crosstalk, I fed the common input but then selected other outputs while still measuring what came out of "A" output:

Worst case crosstalk is -55 dB but gets better if you select C or none. Depending how sensitive your other speakers are, you may hear some bleeding.

Conclusions
The Luxman AS-50R is gorgeously built and has nice functionality. Other than crosstalk, performance is excellent so I think it will do a nice job.

I am going to recommend the Luxman AS-50R.
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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[TimoJ]

Since this is a speaker selector shouldn't you use speaker level signals instead of 4V line levels? i.e. connect output to 4 or 8 ohm dummy load and feed e.g. 100W signal and measure what happens vs. direct connection.

 

[amirm]

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.

Forgot to include Manufacturer Specifications:

 

[IAtaman]

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.

For SINAD it is clear. How about cross-talk - that will be not affected by level either?

 

[amirm]

No. It will be relative.

 

[restorer-john]

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.

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.

 

[restorer-john]

Worst case crosstalk is -55 dB but gets better if you select C or none. Depending how sensitive your other speakers are, you may hear some bleeding.

No you won't. See above.

 

[Scytales]

Interesting device.

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

The speakers would be plugged in the "Common" terminals and the amplifiers under test respectively in the three "System" terminals.

Possible or not ?

Edit :

OK, Luxman have already answered to this question : it is possible !

AS-50R｜製品情報｜ラックスマン株式会社 - LUXMAN

www.luxman.co.jp

 

[restorer-john]

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

The speakers would be plugged in the "Common" terminals and the amplifiers under test respectively in the three "System" terminals.

Possible or not ?

Edit :

OK, Luxman have allready answered to this question : it is possible !

You have to be really careful about doing something like that.

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.

Also, the relays must be set to break before make or amplifiers will be destroyed when switching. Tube amplifiers also cannot be switched in that situation without the potential for damage if they utilize output transformers.

 

[amirm]

Also, the relays must be set to break before make or amplifiers will be destroyed when switching.

There is a distinct delay which tells me that is what it is doing.

 

[staticV3]

There is a distinct delay which tells me that is what it is doing.

What's a "distinct relay" and how does it indicate break before make?

 

[Scytales]

What's a "distinct relay" and how does it indicate break before make?

Not a relay: a delay !

 

[staticV3]

Not a relay: a delay !

Whoops! Thanks for the correction.

 

[Scytales]

You have to be really careful about doing something like that.

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.

Also, the relays must be set to break before make or amplifiers will be destroyed when switching. Tube amplifiers also cannot be switched in that situation without the potential for damage if they utilize output transformers.

Very good points.

A teardown of this device would be useful.

 

[Raticosa]

Thanks Amir for this test, very interesting item.
If I would buy it I would use it in "reverse mode" as amplifier selector, that is connecting two different amplifiers (Hi-Fi and HT ones) to "A" and "B" terminals and the main L and R speakers to "Common" terminals, in order to use my tower speakers with both amplifiers. But I made myself the passive switch with a "military grade" APEM "break before make" toggle switch, with only 5mOhm DC resistance (measured) and much better than the passive selectors you can find on AliExpress or Amazon (i.e. the famous Dynavox Amp-S mkII, bought before making mine but totally rubbish and immediately abandoned, its rotary switch is totally unreliable and bass frequencies were thin and after some weeks I lost the left channel due a defective contact on the rotary switch contacts).
Would be interesting if Luxman would make same item but with only two outputs (A and B) in order to reduce a bit cost and dimensions, just for HiFi and HT switch use.

 

[JSmith]

It is on kind loan from a member

Thanks to this member and for your testing Amir.

discontinued?

It seems to be available new from various sources;

Luxman AS-50R Speaker Selector

Luxman AS-50R is a speaker selector that is capable of connecting up to three speaker systems at once and switching the systems through a touch of a remote control. It also gives you a common output for your favorite amplifier and an ID setting system to mix and match your choice of speaker plus...

audiocubes.com

Luxman AS-50R

Remote Controlled Speaker Selector

www.technologyfactory.eu

https://www.ebay.com/itm/275436796361

... and is still listed in the 2020 product catalogue;

https://luxmanamerica.com/wp-content/uploads/2020/04/Luxman-Product-Catalog-2020-442020-1.pdf

However it's not a current product on their site, so maybe existing old stock;

PRODUCTS | LUXMAN | Seeking higher sound quality

www.luxman.com

A teardown of this device would be useful.

Agree... I was unable to find any other teardowns or schematics of this device.


JSmith

 

[Sokel]

What surprises me the most is it's price tag,I would have never expected a Luxman with such a low price,no matter how simple.
Obviously it delivers as expected.

Thanks Amir!

 

[Endibol]

Thanks to this member and for your testing Amir.

It seems to be available new from various sources;

Luxman AS-50R Speaker Selector

Luxman AS-50R is a speaker selector that is capable of connecting up to three speaker systems at once and switching the systems through a touch of a remote control. It also gives you a common output for your favorite amplifier and an ID setting system to mix and match your choice of speaker plus...

audiocubes.com

Luxman AS-50R

Remote Controlled Speaker Selector

www.technologyfactory.eu

https://www.ebay.com/itm/275436796361

... and is still listed in the 2020 product catalogue;

https://luxmanamerica.com/wp-content/uploads/2020/04/Luxman-Product-Catalog-2020-442020-1.pdf

However it's not a current product on their site, so maybe existing old stock;

PRODUCTS | LUXMAN | Seeking higher sound quality

www.luxman.com

Agree... I was unable to find any other teardowns or schematics of this device.


JSmith

I just ordered one at E-bay.. It says "new from Japan". So, it looks like they are still available.

 

[Endibol]

You have to be really careful about doing something like that.

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.

Also, the relays must be set to break before make or amplifiers will be destroyed when switching. Tube amplifiers also cannot be switched in that situation without the potential for damage if they utilize output transformers.

Thanks for the warnings!

 

[ElJaimito]

You have to be really careful about doing something like that.

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.

Also, the relays must be set to break before make or amplifiers will be destroyed when switching. Tube amplifiers also cannot be switched in that situation without the potential for damage if they utilize output transformers.

Yes NOT suitable on the face of it for use with any valve/tube based transformer output amp. I was about to post the same warning when I saw this! No problem at all with semis. Hmmm. Not sure with Class-D. On first consideration, probably OK, depending on the output configuration. Anyone tried this?