Audio by Van Alstine ABX Comparator Review

[Salt]

I am not saying that's the reason, but there seem to be too many things making this a totally useless appliance for the purpose of a real blind test.

Polite answer, I do agree

 

[pablolie]

If you assume Josh cheated, the comparator doesn't matter, the LEDs don't matter, nothing does. He could have simply made up the results in that case. So this whole disussion about LEDs can only be about the question if they are on or off in test mode. And they are off.

I am not assuming anything. I KNOW it is utter bullcrap to have someone tell competent DACs apart 98% of the time. We have found out it was a useless test. Deal with it.
Note unlike others flocking in here now and demanding Amir works even more on this useless test device... I contributed to make sure we got the device and established its fundamental flaws.

 

[PristineSound]

Well, well. Surprised, surprised.

And I suppose Erin should stop using his ABX moving forward.

 

[amirm]

If you assume Josh cheated, the comparator doesn't matter, the LEDs don't matter, nothing does. He could have simply made up the results in that case.

That's still a possibility. It is not like this is like foobar where you get a printed output. Josh said he got this and that result and to this date, we have accepted that at face value. But a true verification was not done in the form of say, recording a video of him taking the test and achieving said results.

 

[Salt]

If you assume Josh cheated, the comparator doesn't matter, the LEDs don't matter, nothing does. He could have simply made up the results in that case. So this whole disussion about LEDs can only be about the question if they are on or off in test mode. And they are off.

Wait.. with LED off the noise floor of the DUT is supposed to be .....

 

[amirm]

And I suppose Erin should stop using his ABX moving forward.

If he is using for speaker comparison, then it is fine. Using it for much else is problematic.

 

[welwynnick]

The ABX comparator manual says:
So regardless of who cabled up what, the LEDs obviously do not tell you what device is active in ABX testing mode (because they are off). I'm pretty sure this has also already been discussed in the initial thread and it would also make the device immediately and obviously useless to anyone.

This, I think, is the relevant part of Josh's original description of the operation of the comparator:

The user then defines the two level-matched systems to be compared and enters Formal Blind Test Mode. Another command — ON-OFF, then 1 — starts the test. The LEDs go dark, and the VFD shows a “1” to mark the first of eight rounds. A random number generator assigns the “X” system each round. Using the remote, the listener can switch between the “A” system, the “B” system, and the “X” system. A small, uniform click sounds with every button press, concealing whether an actual switch has occurred. The UP and DOWN buttons move through the rounds. Afterward, MUTE button relights the LEDs, and stepping back through the rounds reveals the identity of “X” in each round.

As others have said, the notion that the LEDs are a tell is a complete red herring, especially when the fidelity is relatively poor.

 

[pablolie]

..

As others have said, the notion that the LEDs are a tell is a complete red herring, especially when the fidelity is relatively poor.

You and "others" know as much about the real test environment as I do. You're just assuming. Go buy the device and show us.
I am not claiming it was the LEDs... but then why do they exist, hello? Too many flaws in it, clearly.

 

[shuppatsu]

I guess you were there live, ensuring the testing protocol was executed according to your assumptions.

Moving the goalposts. I was answering your question:

I repeat.. why listen to clicks when you have the source LED telling u whether A or B is active. It's there in the Pic.

At any rate, that question has been thoroughly and repeatedly answered.

 

[amirm]

This whole adventure goes to show how difficult it is to generate truly blind studies.

This is why I said in my video on blind testing and you really should use such tools for yourself. For publishing, the level of rigor goes way up. Here is the video queued up to the right moment:

 

[PristineSound]

If he is using for speaker comparison, then it is fine. Using it for much else is problematic.

Unfortunately, Erin has used it for amplifier comparison, and on multiple occasions.

 

[pablolie]

Moving the goalposts. I was answering your question:

At any rate, that question has been thoroughly and repeatedly answered.

You couldn't answer the question if you weren't there live, sorry.

 

[PristineSound]

There is one thing I think readers should be aware. This product isn't an AVA engineered product; it's just sold under the brand. Not saying AVA makes transparent products or not, I don't know much about that brand, but I just want to make sure that readers are aware.

 

[amirm]

That is true although I wonder if they were going to sell it under their name, why they did not perform some measurements, and looked for any issues it might have (e.g. relay sound). After all, I am sure they kept some of the profits.

 

[PristineSound]

That is true although I wonder if they were going to sell it under their name, why they did not perform some measurements, and looked for any issues it might have (e.g. relay sound). After all, I am sure they kept some of the profits.

Totally agree. If you are going to sell a product under your brand, you should test it to protect your brand.

 

[DonH56]

Mine had A, B, and X LEDs -- and an off switch for rigorous testing. Normally the front panel was dead during tests but it was useful for initial evaluation, debug, and playing around.

The biggest PITA for me was readout, since there was no fancy display. IIRC, I used a shift register with 16 bits as a memory, so I could record at most 16 trials at a time. I had a string of 16 LEDs driven from the shift register so at the end of the trials you threw a switch to light up the LED string to see whether A or B was X for each trial. Actually, the biggest PITA was drilling 16 holes in a straight line so it did not look quite so cheesily home-made.

My sociology courses taught me (among other things) that generating a truly unbiased survey is practically impossible. Engineering taught me that producing a truly transparent ABX tester was similarly difficult. Too many tiny details too easy to mess up. For example, not thinking about floating and bridged amplifiers that became quite unhappy when the tester grounded one of the output terminals. Don't ask how I know that, or how much work it was to revamp the design to include separate relays for (+) and (-) amp and speaker terminals... My line-level inputs were all RCA; I had schematics drawn for an XLR/balanced version but never made it best I can recall.

To be a bit on-topic, I think the store I worked for did bring in a Van Alstine ABX box at one time, but I also think we used it only for amplifier (speaker level) testing. One of the speaker manufacturers (B&W?) brought an ABX box of their own in for comparisons once upon a time. And I tweaked mine to drive an additional set of power relays for cable testing, so we could do ABX speaker cable demos and comparisons, but of course then as now people would say the relays and extra connectors corrupted the tests so they were not valid. Oh well.

 

[welwynnick]

I am not. claiming it was the LEDs... but then why do they exist, hello?

That's exactly what you just did:

I repeat.. why listen to clicks when you have the source LED telling u whether A or B is active. It's there in the Pic.

Explain the picture of the device with two big LEDs identifying the source.

I am not saying that's the reason, but there seem to be too many things making this a totally useless appliance for the purpose of a real blind test.

That was established in post #1 of this very thread. Why the need to keep ranting about it? The question has been answered.

 

[pablolie]

That's exactly what you just did:

Your reading comprehension issues will make this the last post I ever direct your way.
I correctly stated the device can provide both visual and audible cues about the DUT port. Whether or not that was relevant neither you or I know. Even though you keep pretending to.

The device is garbage. Proven. Let's close this thread

 

[Bob101]

Wake up, they already are:

Reference ABX hardware design and implementation

Update 2026-09-11: boards ordered! https://www.audiosciencereview.com/forum/index.php?threads/reference-abx-hardware-design-and-implementation.72589/post-2679015 Edit 2026-07-31, see progress update at...

www.audiosciencereview.com

Thank you for your polite reply.

 

[Karmacoma]

But as the great philosopher Yogi Berra said, "In theory there is no difference between theory and practice. In practice there is."

Not so great here imho.
A theory that doesn't work as intended in practice needs revision.