APx555: Should I or should I not?

Discussion in 'Tales from the Bully Pulpit' started by purr1n, May 17, 2021.

  1. purr1n

    purr1n Building Magnis part time because it's peaceful.

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    So it's come down to this. AverLAB is kaput. After waiting years for them to get their software together, they never came up with two-tone tests, multi-tone tests, nor fixed some serious bugs for raw data collection. It's still a great analyzer, but it's becoming less and less useful: too long to set up, clunky UI, slow FFT calculations, needs external HV probes to measure amps, can't do potentiometer matching, etc.

    The question is between APx525 or APx555. Or maybe their new measurement software that works with RME's USB thingy. Yes, AP now sells their software.

    I'm tending toward the real AP hardware units because the inputs can take HV for amps. This would be a massive time saver in addition to offering better measurements. I'm kind of tending toward the APx555 - mainly because the analog generator is insanely good. With digital measurements (DACs), the results are close enough, a few db off. However with amp measurements, the APx555 SINAD results are a good 7db better around 0.5Vrms. Even more than importantly than this is that the distortion patterns with the APx525 showing a bit more second order. Finally, the FFT processing speed is amazeballs and the UI of the AP is spectacular. At first I was scared of the interface because so many options are laid-out - but after 60 seconds, it all totally makes sense.

    I don't know if I want to get the APx555 because it seems like e-peening. Then again, I am gravely concerned about the misuse of measurements considering how easily they can be borked, and feel that the only one around to offer "legitimate" peer review of the guy with the APx555 would be me.

    This would be my own money, from my savings, and from the ads and sponsors paying for this. The Patreon still goes to loaners, shipping costs, site operations, etc.
     
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    Last edited: May 17, 2021
  2. AdvanTech

    AdvanTech Friend

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    Any way I can donate directly to an APx555 fund?
     
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  3. purr1n

    purr1n Building Magnis part time because it's peaceful.

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    PP: https://www.paypal.com/donate?hosted_button_id=RXRVCV2WTXYEY

    QR Code.png

    (changed PP email to the link above since people have been trying to hack into my PP account on an almost daily basis - also not the [email protected] one or Patreon, which again is for loaners)

    And I won't just be doing SINAD (boring). I feel there's a lot more to explore that may (or may not) tell us why ESS DACs sound the way they do, or AKM DACs sound the way they do. Also would be fun to do stuff like set the record straight on potentiometers... maybe frame them in proper visualizations so if channel balance is 0.5db off, it's not graphed like it was the end of the world. Or a second look at well measuring Chi-Fi gear three months after the fact to see if off-the-shelf production units still measure the same. Deep in my heart, I feel there is some funny stuff going on.

    There must be balance in the Force. Sauron and his one ring of SINAD has loomed over the land for way too long.
     
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    Last edited: May 17, 2021
  4. chakku

    chakku Friend

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    If you do grab an APx555 first thing I would hope for is a showcase of just how easy it is to fuck up and/or manipulate measurements with the analyzer and possibly what the layman could look out for which raises suspicion about a particular set of measurements.

    An idiot's guide to Audio 'Science' Reviews or something of the sort.
     
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  5. purr1n

    purr1n Building Magnis part time because it's peaceful.

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    Oh Schiit, I could totally do that. In fact, I've already run into it with the APx525 I've been playing with right now.
     
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  6. Senorx12562

    Senorx12562 Case of the mondays

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    Your call, and I don't know your financial situation, but I'd think that $ was better spent elsewhere.
     
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  7. Philimon

    Philimon Friend

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    Like what? Another overpriced headphone review? APPx555 will help stfu Amir for all’s benefit and entertainment. And Purr1n is willing to do all the work for free. ... How much is an APPx555? We all chip in x amount.

    Edit: holy shit $28k base. I agree w senorx
    https://www.prosoundnetwork.com/gear-and-technology/audio-precision-apx555-audio-test-system#:~:text=The APx555 is an expensive system ($28,300 base,,like getting to drive a fine sports car.

    $100 each member cover it? Refund if goal not met possible?
     
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    Last edited: May 17, 2021
  8. purr1n

    purr1n Building Magnis part time because it's peaceful.

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    Imma gonna order it anyway regardless of donations. Don't want to make it seem that I'm waiting for handouts. I've already spoken to AP reps. I believe the B version which is the latest is a bit more than that. It's pricey for sure, but hey, this is the way I've always lived my life. If I have enough (and a little bit more) to take care of my family, then I'm good.

    Hey, someone's gotta do it.
     
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  9. Philimon

    Philimon Friend

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    Fundraiser? Sell sbaf diy headphone kit or pre-built? Im keen on T50rp or Elleven Acoustica P1 drivers.
     
  10. purr1n

    purr1n Building Magnis part time because it's peaceful.

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    Laser etched Ahegao Hentai Waifu on tops of IEMagnis. I'll sell those.
     
  11. Merrick

    Merrick A lidless ear

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    All I can say is I’m excited to see what can be done with this machine beyond the most basic measurements. I feel like the way Amir uses his is like getting a TOTL sports car and driving it in first gear at 35mph on the Autobahn.
     
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  12. Philimon

    Philimon Friend

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    Golden Schlong etch or no deal.
     
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  13. GoodEnoughGear

    GoodEnoughGear Evil Dr. Shultz‎

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    So long as you can do more investigative/explorative work than just matching ASR I say forge ahead. Maybe take a % of donations over time.
     
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  14. crenca

    crenca Friend

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    Made a small donation. Have too much sunk into audio right now, but I am planning some sells and will donate a percentage...
     
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  15. purr1n

    purr1n Building Magnis part time because it's peaceful.

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    Fair enough. Let me earn it. I'm sure better with e-peen gear, more will come.

    The APx555 was meant for research, discovery, science, engineering. Not SINAD bullshit. It's time to take back the word science.
     
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  16. bboris77

    bboris77 Friend

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    A small donation made...time to level the playing field. It will be fascinating to see truly independent and unconventional measurements of gear.
     
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  17. Armaegis

    Armaegis Friend

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    Just out of curiosity, is a Prism dScope in the same price range? Since @atomicbob is our resident yoda on that gear.
     
  18. Elnrik

    Elnrik Super Friendly

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    I assume this means published procedure, followed every time, nothing left out because it is too time consuming or inconvenient, regardless of the price of the item being tested. If you did a waterfall plot on a Focal Utopia, you do one on a Koss Porta Pro too.

    Science is not (just) information, it's a methodology.
     
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  19. purr1n

    purr1n Building Magnis part time because it's peaceful.

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    Yes, consistent and repeated methods. This has been easier for me to do with headphones because I DIY'd not only my hardware measurement rigs, but also much of my software, over the past 11 years. With DACs and amps, it's been much more difficult and I've been spotty - because no one tool I currently have can do it all. I've had to resort to taking a bastardized approach combining AverLAB, ARTA, MOTU, etc. and this is a PIA - infuriatingly time consuming.

    There is also discovery. Are there certain behaviors which are common to ESS chip DACs, AKM DACs? Certain topologies? Certain patterns which explain what we hear. The APs work FAST. 32k FFT windows with average of 10 measurements, in the time that it takes the AVER a single 32k FFT. I'm hoping with increased speed, superior interface, and ability to band-pass signals, I may stumble upon interesting results. The AP API will work with NET. Could start doing some more complex analysis and more interesting visualizations.

    Most of the time, the hunches lead to a dead end. But sometimes good things happen. The results usually will not be as obvious or relatable as something frequency response, but sometimes tidbits like distortion vs level or attack / decay envelopes contribute additional minor information that helps to complete the bigger picture.
     
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  20. penguins

    penguins Friend, formerly known as fp627

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    In all seriousness, I also don't want to see SBAF take on ASR directly.
    ASR has too much of a "hand-holding and making you feel better about spending your money" feel to it. "Oh look you're so smart with this purchase you saved so much money buying this thing for $200 with SUPER DUPER MEASUREMENTS that shows it's CLEARLY SUPERIOR." Obvious caricature, but you know what I mean. Unfortunately, I think the only way any other forum would become a direct competitor to ASR would be if they engaged in the above like-behavior.
    Additionally, I do not think that simply providing random APx measurements (as say HF and others do sometimes) will get people off of ASR. If anything, it may help validate their message of "must do measurements the ASR way" (again, not that measurements themselves are bad). On top of this, some people "just want to believe in something" for whatever reason, some people will say "oh it's just a grudge match, ignore SBAF results", etc.

    However, if you're set on the APx, this would be my 2c:
    1. Looks like @chakku beat me to it but yes, if this is being purchased in response to ASR, the first thing I would do would be to show how easy it is (or not) to bork measurements with an APx. I would then show why any other random piece of gear may be sufficient (or not).
    2. You already mentioned it, but yes, prove or disprove golden samples, etc.
    3. You touch upon it right above, and I don't know what an APx555 (or 525) can or can't do as I've never cared enough to look, but it would be interesting for the audio community at large to see if "subjective traits" and "currently unused or unknown measurements" can be made or correlated. I think many other things "subjective things" mentioned on SBAF (or HF, etc.) could be approximately characterized with actual measurements, but the audio community at large simply hasn't done so yet, hasn't had incentive, or hasn't come upon a clearly defined way to characterize subjective hearings with these "other" measurements. I can give examples if needed.
    This of course may be much easier said than done, especially for things that may end up involving multiple-factor interactions.
     
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