LYNEPAUDIO B049 Audio Switcher Review

[restorer-john]

Before piling onto this thing, it should be determined if it is faulty or not.

70mV asymmetric clipping with an active 5V supply suggests something is wrong.

 

[LTig]

Maybe @amirm can open it and show some pics.

 

[DavidGA]

I sent this to you!

I sent it because I bought one thinking it was a passive switch, and then was surprised to discover that it needs a 5v power supply. I opened it up and discovered that it has op-amps inside, which is weird for a switch.

Edit: Attached a third image showing a close-up of the component values, in case that's useful to anyone.

 

[amirm]

I sent this to you!

Oh thank you. What is the actual brand name?

 

[DavidGA]

Oh thank you. What is the actual brand name?

This is the eBay listing I bought it from: https://www.ebay.com/itm/353987512966

No brand name other than what is written on the device is obvious. "Lynepaudio". They seem to only be sold on eBay and Aliexpress.

 

[DavidGA]

While I'm here, can anyone else recommend a multi-in multi-out RCA switch that isn't a piece of junk? My office desk has multiple sources and multiple possible outputs, and this switch seemed to solve all my problems. (Glamorous in-use photo attached, before I ripped it out for being crap.)

I'd really like to replace it with something that isn't awful. A passive switch would be perfectly fine, as long as it has enough input and outputs.

 

[Katzz]

Its still begin sold on aliexpress, so far a couple of units have been sold (please someone correct me If Im wrong since this product doesnt have a number model) On ebay it seems that 6 units have been sold with 0 reviews and in amazon there is only one star review from 2022 explaining that the product doesnt work

 

[DavidGA]

OK, since I still have mine, I hooked it back up. I don't have any fancy audio analysis equipment, but I do have the world's cheapest oscilloscope, and two very aged ears. Since the distortion was so obvious in the review, I figured I could have ago. And I did find something!

With one output enabled:



With two outputs enabled:



Oh dear! And with two enabled, the tone is very obviously distorted.

So... maybe it's just not designed to have more than one output enabled? The push buttons don't move much when they're on, so it's very easy to have one turned on and not realise it.

Of course, if you're not supposed to have more than one enabled, then why are they buttons and not another dial. That, I don't know.

 

[Palladium]

+1 from me for "why even make this actively powered at all?".

 

[amirm]

+1 from me for "why even make this actively powered at all?".

Since it can take one input and send it out on four, it is kind of a distribution amplifier. Buffering allows better drive capability in case the loads are lower impedance.

 

[tmtomh]

Thanks @DavidGA for your testing - very helpful! If, as @amirm notes, this is supposed to function as a distribution amplifier, then that would explain why it's designed to to have more than one output enabled. And in that case the design would appear to be seriously flawed, per Amir's testing and DavidGA's corroboration on another example of this unit. Only remaining question in that case would be why Amir's example clips on the bottom of the waveform while David's clips on the top.

 

[DavidGA]

Thanks @DavidGA for your testing - very helpful! If, as @amirm notes, this is supposed to function as a distribution amplifier, then that would explain why it's designed to to have more than one output enabled. And in that case the design would appear to be seriously flawed, per Amir's testing and DavidGA's corroboration on another example of this unit. Only remaining question in that case would be why Amir's example clips on the bottom of the waveform while David's clips on the top.

That could easily be a quirk of my wiring, or my extremely awful oscilloscope, inverting the waveform.

 

[RigorDude]

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

Did you test any inputs or outputs other than in1 and out1?

 

[DavidGA]

Did you test any inputs or outputs other than in1 and out1?

In my test, the scope was connected to out4, and I also had some speakers on out3. Doesn't seem to matter which ones you use, only how many you have enabled.

 

[amirm]

Did you test any inputs or outputs other than in1 and out1?

I did not.

 

[Emulator II]

I bought this device a few years ago:

Of course, I assumed that I could control the volume for both inputs using the built-in potentiometer. But I was completely wrong: For input 2, the signal is simply looped through and output at full volume. Luckily my power amplifier wasn't fully turned up when I tried it out. Who the hell thinks up this crap, makes it, and then sells it?
Of course, the dealer in the Far East denied everything and simply offered to send this piece of junk back at my expense.
Long story short: avoid this “brand” at all costs.

 

[solderdude]

I'd really like to replace it with something that isn't awful. A passive switch would be perfectly fine, as long as it has enough input and outputs.

The manufacturer seems to have added 'buffers' in the output path because one can direct one input to 4 outputs.
I would just remove all the SMD parts and by-pass the circuit (connect input and output of the circuit) and you can use it as a proper switcher.

It is not an IC in there though but most likely an AO3402 MOSFET which is used as a source follower.
That MOSFET is not designed for that purpose but rather it is intended for switching purposes.
It also explains why the negative side of the signal is clipped.

 

[JeremyFife]

Ouch

 

[AuricGoldfinger]

...It is not an IC in there though but most likely an AO3402 MOSFET which is used as a source follower.
That MOSFET is not designed for that purpose but rather it is intended for switching purposes.
It also explains why the negative side of the signal is clipped.

That was also precisely what I looked for. It’s a very strange design decision and doesn’t make sense, to me at least. Had this switcher been conceived as sealed relay-based device with op amp buffers, or even no buffers at all, it would have worked.

 

[dzerig]

So if someone sends in a piece of gear here and the maker cannot be reached, or even known for sure, should Amir simply not test it?

If the results are so unusual that they cannot be reasonably explained, it could be prudent not to publish if the results are so far out of specification that they don't make sense.

On the other hand, if you can't find them, maybe they can't find you.