[avahifi]

We have refined the design of our ABX component comparator and also made it much more affordable.

It now is direct coupled in to out (no capacitors in the signal path, no active solid state components, just carefully designed pop free relays and instant quiet switching with silicon volume controls for exact level matching.

It allows direct comparisons of two preamplifiers, two power amps, and three set of speaker systems either separately or at the same time.  It even allows comparisons of interconnect cables.

Here are the details:

The price is $999

ABX Switch, rev 2, by Audio by Van Alstine 01-26-14

The ABX Switch allows seamless switching of up to two sources, two amps, and three sets of speakers.
Controlled by universal remote, usually from the listening position, the ABX switch has the capability of:
• Precise volume level matching, within 0.1 db, of any selected system.
• Infrared universal remote control.
• Blind test mode (2 of them) can force evaluation strictly by how it sounds.
• Works with or without a subwoofer.
• Programmable power up state and adjustable display brightness.
• Persistent volume settings power up the same as they were when last powered down.
• Multiple systems can be set up permanently and switched in/out instantly with remote control.
• Low noise
• Built in “Y” splitter can be used to drive two units with one source
• Allows selection of up to two speakers at the same time
• Mute entire system with a single button
• Gold plated RCA connectors for line level signal connections
• Gold plated 5-way dual banana connectors for speaker level signal connections
• DC coupled (no capacitors in the signal path).

If you are interested, contact me and I can e-mail you the full operation manual including photos inside and out.

[jtwrace]

price?

[avahifi]

Whoops, add price ($999) to original posting.  Note that the original version would have been twice as expensive as it was MUCH more labor intensive to build.

Frank

[Nick B]

Didn't see this on the website. So, does this kinda function like a passive preamp?

[avahifi]

Interesting things you can do with our ABX comparator:

If you want to make a quickie and easy blind test of two power amplifiers, for example.  Attach them both to the ABX box, use the ABX box level adjustments to match signal levels from each, then simply hit the botton that turns off all the indicator lamps on the ABX box.  Switch back and forth rapidly between the two amps under test a few times on the same program material and you will soon loose track of which amp is which.  Then do more careful listening and when you are certain of which amp you are listening to, turn the indicator lamps back on and see if you are right.  Repeat process several times.  Can you really pick out what you are hearing?  Once you loose the ability to hear with your eyes, all bets are off.

Of course you can do the more formal built in test procedure for the most accurate and foolproof results too.

Do you want to see if your favorite wonderful good sounding capacitor is really really better.  For this you will need two identical samples of the component you are playing capacitor swaps with.  Put all the good sounding parts in one sample, keep the other one stock, and run the ABX test between them.  How wonderful are your capacitors now?

You can even put interconnect cables to the acid test by using two identical preamplfiers.

There are many ear opening things the ABX box can help you understand.

If you are a speaker manufacturer or audio electronics manufacturer you definitely need our ABX box.  You probably will find it is your most important test too.

Frank

E-mail me at avahifi@comcast.net with your e-mail address and I can send you a .pdf file of the user manual complete with photos and hookup diagrams.

[Nick B]

thx     email sent

[PMAT]

Certainly not to be feared  I have perfect hearing.  If I had designed and built this thing it would have been with an evil smile. What a great bullshit eliminator. This thing is dangerous!

[Wayner]

It doesn't solve the problem of long term listening and listening fatigue. You can't ABX that, only by long term listening sessions. It can help diagnose a difference between components for the short term. I  have found that many times, components that I initially liked, failed in the long run, perhaps due to listening fatigue, or the newness of it wore off.

The device is designed to do quick comparisons.

Wayner

[Freo-1]

It doesn't solve the problem of long term listening and listening fatigue. You can't ABX that, only by long term listening sessions. It can help diagnose a difference between components for the short term. I  have found that many times, components that I initially liked, failed in the long run, perhaps due to listening fatigue, or the newness of it wore off.

The device is designed to do quick comparisons.

Wayner

Agree with this 100%.  It can show differences that are readily noticeable, but only long term listening with your specific system in your listening environment can really help sort the wheat from the chaff. 

[avahifi]

I am not sure what one means by long term, but certainly you can take as long as you want to listen to one component before switching to the other one.  Just leave the unit in the indicators hidden mode, and hit the swap button once in a while (or every few days).  In the formal test mode it will keep track of your choices for you.

Note that in the quickie mode, you are making the choice as to when to switch, and the the ABX box will not do a fake switch in this mode.

Frank

[guf]

is there a way we can ABX the new ABX box to the OLD ABX box? 

[Speedskater]

It doesn't solve the problem of long term listening and listening fatigue. You can't ABX that, only by long term listening sessions. It can help diagnose a difference between components for the short term. I  have found that many times, components that I initially liked, failed in the long run, perhaps due to listening fatigue, or the newness of it wore off.
The device is designed to do quick comparisons.
Wayner

These all sound like statements from a person who does not understand how to do a sensitive ABX test.

For a truly sensitive ABX test the listener should:

a] Have auditioned and be familiar with the sound of both components before starting the test.
b] Chose musical selections that best highlight these sound differences.
c] Set the volume control to a preferred level.
d] Have control of which input to listen to (A), (B) or (X) and when to switch inputs.

[avahifi]

Our ABX box easily and seamlessly allows the testing method that Speedskater suggests.

Frank

[Freo-1]

These all sound like statements from a person who does not understand how to do a sensitive ABX test.

For a truly sensitive ABX test the listener should:

a] Have auditioned and be familiar with the sound of both components before starting the test.
b] Chose musical selections that best highlight these sound differences.
c] Set the volume control to a preferred level.
d] Have control of which input to listen to (A), (B) or (X) and when to switch inputs.

You are making a cavalier assumption on the the person's knowledge you have no way of knowing one way or the other.  He may very well understand the entering arguments as stated above, and could still come to the same conclusion.  Some of the hard core DIY crowd woulld tell you that the ABX box itself is going to alter the sound in some minor way by choice of resistor types, pots, impedance deltas from the introduction of the ABX device, etc.

I'm not saying that the ABX device isn't a good tool (it is).  I'm just saying it has limitations just like any part of the playback chain.  It is certainly debatable as to the scope of the change (I'm sure it's very litle), but it's not zero.

[newzooreview]

I visited Dennis Murphy a few years ago, who designs the crossovers for Salk speakers, and the development of the SoundScape line (and likely eariler Salks) was done with a Van Alstine ABX box. Both selection of drivers and ground truthing of computer modeled crossovers relied on the ABX. Dennis used it to walk me through the differences in the Salk prototypes he had on hand. Fun stuff.

[avahifi]

For what its worth, the first major ABX test we did was to test the ABX box with itself.  We wired it up specially so that in one test position the signal was straight through the box with no internal connection, and the other with the box in circuit.  We could not hear any difference in short term or medium term listening tests.  Thus we think the box is pretty transparent.

The ABX box is good enough to reliably pick out subtle differences between our various products and to guide our design process quite well so we suspect it can be a useful tool for anyone needing a different way to compare audio components. At least it forces one to listen with their ears rather than with their eyes or cash reserves.

Frank Van Alstine

[Freo-1]

I still have to wonder about impedance matching when inserting the ABX box with tube based preamp and power amps when comparing to solid state amps. 

[mav52]

Hey Frank can this thing be made to AB external DACS, add a USB port etc...

[AJinFLA]

It doesn't solve the problem of long term listening and listening fatigue.

Nope. It's not meant to control ones moods, emotions and perceptions as they vary significantly over time. It's not testing you. Its testing the "audio" component.

You can't ABX that, only by long term listening sessions.

There is no time limit on ABX. None.
Now, for reliable information related to hearing, quick switching corresponding to aural memory decay is a must. But once again, if you need a year for your mind to wander about, there is nothing preventing that in an ABX test.

I  have found that many times, components that I initially liked, failed in the long run, perhaps due to listening fatigue, or the newness of it wore off.
Wayner

Sure. Your mood, perceptions, etc, etc. changed over time like every other human being on earth. What would that have to do with the audible characteristics of the component? That's what this device is for. To determine, what, if any.
Seems pretty reasonably priced too.

cheers

AJ

[PMAT]

I agree with the long term fatigue stuff but most people here should get a good read in less than a week. The "air" between wall sockets should be readily apparent.    it would be nice to not have to wear my chest waders just to read the latest posts here on AC. By the way dovetail joints in hardwood sound so much better than butt joints.