Amir Buys a New Audio Precision Analyzer (APx555)!!!

[SSS]

Working on similar audio gear from 1960 to the 1980ies I use a E-MU Tracker soundcard with appropriate software like ARTA and audiotester.
Further of course a dummy load for output power, Sound Technology measurement instrument for level and THD.

 

[amirm]

The manufacturers of Audio (Home Stereo) go to great lengths to supply performance specifications of their equipment. How can a small shop implement these testing procedures into daily practices.

General answer is that you can't. There is usually insufficient information in the spec sheet. That said, some specs are better than others like what you show. In those cases, I am able to approximate them and not worry about small variations. If i get 0.003% and they say 0.002%, I consider that good enough verification.

 

[AnalogSteph]

If you know what you are doing (which is a pretty big if), a lot of these things can be verified on a shoestring budget using little more than a midrange audio interface plus misc. external components like speaker dummy loads, attenuators and inverse RIAA. You won't have the automation of an AP but at 40 dB less cash outlay you'll probably be able to live with that.

 

[KSTR]

How can a small shop implement these testing procedures into daily practices? My primary work is with Receivers, Integrated Amps, Preamps and Power Amps that were produced in the 1970's & 80's. Question is how to duplicate these test, procedure and needed equipment?

IMHO the investment in a used AP or other "serious" audio analyzer quickly pays off, and be it only their robustness when abused. There still is a steep learning curve because more often than not the operator is the limit, not the gear. If your budget is very limited but your knowledge is not then you can go a long way with any reasonable ADC/DAC combo unit plus a set of self-made custom accessories and some helper hardware like protected auto-ranging units offered as DIY kits or ready-made units, etc. On the software side, we have, among others, Multitone and REW free-ware/donation-ware programs, both of which are excellent.

 

[Booker]

Audio Precision APx555: When Science Meets Audiophile Magic

As I unpacked the industrial-grade APx555 B Series, I couldn't help but notice the stark utilitarian design of its BNC connectors. sigh If only Audio Precision understood that gold-plating isn't just about corrosion resistance - it's about the soul of the signal! Still, I must soldier on in my quest for audio truth.

After the mandatory 48-hour warm-up period (resting on a carbon-fiber anti-vibration platform), I began my critical listening sessions. The first 1 kHz sine wave literally took my breath away. Such purity! Such harmonic separation! Never have I heard sine waves rendered with such holographic precision. The soundstage was so deep I could practically see into the foundations of mathematics itself.

The typical THD+N of -120 dB creates a background so black that a black hole would look like a disco ball in comparison. And that >1 MHz bandwidth! Finally, I can hear those ultrasonic harmonics that lesser "high-end" analyzers simply can't resolve.

The internal architecture... well, I must admit being slightly disappointed by Audio Precision's stubbornly pragmatic approach to connector choices. Would it have killed them to use at least some cryogenically treated terminals? But I digress...

When I ran the frequency sweep from 20 Hz to 80 kHz, I nearly wept. Each frequency occupies its precise location in space, the phase coherence is absolute. This isn't measurement - it's a TRANSCENDENT EXPERIENCE.

But the jitter analysis absolutely floored me - the APx555 can generate and analyze jitter with such precision that you can hear individual picoseconds dancing in the air. And that noise floor! So quiet that vacuum itself sounds like a heavy metal concert in comparison.

For the price of a luxury car, you get an instrument that finally bridges the gap between audiophile passion and scientific precision. Though frankly, with a few modest upgrades - maybe some Vibrapods under those pedestrian feet, perhaps some quantum-tunneled signal paths - this could have been truly perfect.

Verdict? Despite AP's puzzling resistance to audiophile-grade connectors, it's still an absolute reference. Game changer. A must-have for anyone serious about audio.

MF​

 

[gino1961]

fwiu the APx555 is capable of SOA performance as it is I would not touch anything
Maybe i would just add a nice 60kUSD IEC power cable i have seen in a commercial

 

[Sal1950]

fwiu the APx555 is capable of SOA performance as it is I would not touch anything
Maybe i would just add a nice 60kUSD IEC power cable i have seen in a commercial

LOL