AVA ABX Comparator Switchbox Review

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dB Cooper

Re: AVA ABX Comparator Switchbox Review
« Reply #20 on: 8 May 2015, 03:34 am »
Both interesting articles, but Cordell kept referring to amps 'misbehaving' (distinct from clipping) and I found myself getting frustrated that the interviewer never asked, "So what would constitute 'misbehavior'?"

Odal3

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Re: AVA ABX Comparator Switchbox Review
« Reply #21 on: 8 May 2015, 04:04 am »
Rusty & R - thanks for the pointers! Much appreciated.
« Last Edit: 12 May 2015, 03:41 am by Odal3 »

Rusty Jefferson

Re: AVA ABX Comparator Switchbox Review
« Reply #22 on: 12 May 2015, 02:46 am »
That works if comparing different electronics while the speakers are the same.  But you'll need a SPL meter when comparing different speakers.

Granted, however does anyone really A/B/X speakers?  I mean, sure we compare speakers, but they are so different sounding I can't imagine not getting 100% percent accuracy differentiating between 2 pairs of speakers using an A/B/X test.  Maybe we couldn't tell which brand was which, but I can't imagine not being able to distinguish between 2 pairs.  Used to compare $1000 vs $10,000 amplifiers is what double blind and A/B/X testing is about.  If meeting the criteria I stated in post # 18, no one is going to be able to distinguish between the 1k and 10k amps.  Eye (ear) opening.

R Swerdlow

Re: AVA ABX Comparator Switchbox Review
« Reply #23 on: 12 May 2015, 02:05 pm »
Granted, however does anyone really A/B/X speakers?  I mean, sure we compare speakers, but they are so different sounding I can't imagine not getting 100% percent accuracy differentiating between 2 pairs of speakers using an A/B/X test.  Maybe we couldn't tell which brand was which, but I can't imagine not being able to distinguish between 2 pairs.  Used to compare $1000 vs $10,000 amplifiers is what double blind and A/B/X testing is about.  If meeting the criteria I stated in post # 18, no one is going to be able to distinguish between the 1k and 10k amps.  Eye (ear) opening.

True, you don't have to go to great effort to hear differences between speakers.  But people do tend to favor the sound that is louder, so if different speakers have different sensitivities, the more sensitive one will sound louder.  AVA's device allows an easy way to separately adjust the volume of each speaker so a listener can quickly switch back and forth and hear two speakers at equal loudness.

Speedskater

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Re: AVA ABX Comparator Switchbox Review
« Reply #24 on: 12 May 2015, 02:39 pm »
The 'X' part of an 'ABX' test is to determine if there are "Just Noticeable Differences" (JND/JDT) between 'A' and 'B'.
A well run ABX test an is extremely sensitive test.  Some industry pros would say that it's too sensitive. The smallest uncontrolled variable can skew the results.
With most loudspeakers the difference are much greater than 'JND', so an 'AB' test to determine a preference is appropriate.

avahifi

Re: AVA ABX Comparator Switchbox Review
« Reply #25 on: 28 May 2015, 08:48 pm »
I have rewritten the ABX Comparator user manual to make it much more user friendly.

I even then had my secretary/assistant, Mary, go through all the functions on the ABX Comparator using the new user manual and she was able to make the ABX Comparator do exactly what she wanted it to do.  No issues, no bugs, no confusion.

The new manual, photos and diagrams and all, is available here (scroll down to bottom of page).

http://avahifi.com/index.php?option=com_content&view=article&id=271&Itemid=238

Frank Van Alstine

janneman

Re: AVA ABX Comparator Switchbox Review
« Reply #26 on: 12 Sep 2017, 01:26 pm »
Late to the party, but here goes: I have one of these units, originally purchased directly from Frank, that is surplus to requirent. Fully functional, as new, with user manual and remote control. If interested, make me an offer to jandidden01 at gmail dot com. Located in Europe but will ship worldwide.

Jan Didden

witchdoctor

Re: AVA ABX Comparator Switchbox Review
« Reply #27 on: 12 Sep 2017, 02:14 pm »
Bob Carver's take on what makes amps sound different:

https://youtu.be/W-qqdYBsgZY

dB Cooper

Re: AVA ABX Comparator Switchbox Review
« Reply #28 on: 12 Sep 2017, 09:42 pm »
True, you don't have to go to great effort to hear differences between speakers.  But people do tend to favor the sound that is louder, so if different speakers have different sensitivities, the more sensitive one will sound louder.  AVA's device allows an easy way to separately adjust the volume of each speaker so a listener can quickly switch back and forth and hear two speakers at equal loudness.

Where is the level balancing done? If at the speaker output, wouldn't that potentially change the sound due to changing the output impedance seen by the speaker?

janneman

Re: AVA ABX Comparator Switchbox Review
« Reply #29 on: 13 Sep 2017, 06:29 am »
It is done at the signal level. You can for instance use a single source, route it to the power amp via two paths that have signal levelling, to the power amp, then from the power amp to the speaker selection path. It is all switched syncronously, and at any one time you always have the same source, same power amp (if that is what you want).
It's a pretty clever unit, actually!

BTW The user manual is attached to my earlier post.

Jan

avahifi

Re: AVA ABX Comparator Switchbox Review
« Reply #30 on: 13 Sep 2017, 12:34 pm »
If you are selling your AVA ABX Comparitor as used in Europe, note that it probably is wired for 240V AC.

We  can change it back to 120V if desired.

Frank

janneman

Re: AVA ABX Comparator Switchbox Review
« Reply #31 on: 13 Sep 2017, 12:45 pm »
Hi Frank, yes  it is set for 230V. I believe it is a matter of putting the primaries in parallel instead of series to make it 110V. I probably could do it myself.

Now that I have your ear, so to say, can you see what date I purchased it? I have an interested party who asks about that, and don't have the invoice anymore...

thanks beforehand,

Jan


Mary

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Re: AVA ABX Comparator Switchbox Review
« Reply #32 on: 13 Sep 2017, 03:59 pm »
Hi Jan,

You Purchased this unit in February, 2016.  It is indeed wired for 240V operation.

Mary

janneman

Re: AVA ABX Comparator Switchbox Review
« Reply #33 on: 13 Sep 2017, 05:36 pm »
Thanks Mary, you're a star!

Jan

Hiphile

Re: AVA ABX Comparator Switchbox Review
« Reply #34 on: 13 Sep 2017, 06:48 pm »
So... after all this years Mr. Julian Hirsch was right! Darn. :duh:
https://www.soundandvision.com/content/reconsidering-julian-hirsch

janneman

Re: AVA ABX Comparator Switchbox Review
« Reply #35 on: 13 Sep 2017, 07:29 pm »
ABX is sold.

Jan