I had the idea of improving THD+N by paralleling MDAC(just chip2chip on two floors) and doubling capacitors. The limiting factor is N i.e. noise, the THD is also not really cool but within -130-140db@1k, so the only way to improve THD+N is to reduce the impedance of MDAC. As I remember MDAC has 10k if not 20k ladder.
If you plan to use USB to control the AP, note that only the newer AP boxes will work with the USB-APIB interface. Below is what I received from AP when I asked about it some 7-8 years ago:
System Twos that won’t work with USB interface:
Cascade:
Tom
System Twos that won’t work with USB interface:
- 2022
- 2222
- 2322 (48k)
- 2300 (48k)
Cascade:
- 2422
- 2522 (96k)
- 2500 (96k)
- 2122
- 2622
- 2722 (96k)
- 2700 (96k)
- 2700 Series:
- 2702
- 2712
- 2722-192k
- 2720-192k
Tom
Hi Guys
Audio Precision S1, S2 & S2c Systems work on ApWin 2.24. They will not work using AP USB box running on ApWin 2.24
The ApWin 2.24 many time won’t run on OS like Vista, Win7 & later as many machines don’t support ISA, PCMCIA or PCI cards.
Ap’s USB Box needs AP2700 software to run and it will control S2c (Cascade type systems)
The APIB USB ADAPTERS (Non AP) will run any S1, S2 & S2c Systems and ATS2 using V1.5 (not V1.6x as this version has the USB support built in, use AP’S USB Box).
I hope this info helps.
Duke
Duke, some Chinese company that sells an illegal copy of APx525, offers mode for oldest APs S2 like SYS2222 to run with APIB-USB i.e. AP2700. It is simple and inexpensive but you'll lose the ability to use DSP.
You got a link to this Chinese clone? I wouldn't dream of buying one, but I am intrigued. It would have to be one of the most niche items I've ever seen copied. You can understand why they copy Beats Headphones (massive market), but considering most AA makers have quit the market due to dwindling sales in recent years, copying an AA seems a little like copying sundials in 2022.
Good grief! I don't think they've copied it enough cosmetically to give AP much hope of successfully suing for registered design infringement, but I'd be very, very surprised if they haven't infringed multiple AP patents internally. As to whether AP want to challenge them in court would be another thing... (AP's UK rep told me another AA OEM in Europe has allegedly used AP IP, and at this point, AP haven't sued).
That thing is not cricket.
That thing is not cricket.
Hi IVX
Why AP does not have service manuals?
Another company made an Audio Analyzer and copied one of Bruce’s special tricks to improve the oscillator’s distortion products. Their service manual was the same as our System One. That was when Bruce said “NO NEW SERVICE MANUAL WILL BE MADE”. Don’t give them our secrets.
The first Chinese copy was the APX515 and it even use the same Eeprom constants as the original box with many tacked on parts to sort of make it work. Bruce was not happy.
This was 6+ years ago when about the time I was doing the APX511.
My APIB USB ADAPTER works just like an AP card, full function.
Duke
Why AP does not have service manuals?
Another company made an Audio Analyzer and copied one of Bruce’s special tricks to improve the oscillator’s distortion products. Their service manual was the same as our System One. That was when Bruce said “NO NEW SERVICE MANUAL WILL BE MADE”. Don’t give them our secrets.
The first Chinese copy was the APX515 and it even use the same Eeprom constants as the original box with many tacked on parts to sort of make it work. Bruce was not happy.
This was 6+ years ago when about the time I was doing the APX511.
My APIB USB ADAPTER works just like an AP card, full function.
Duke
as you can see that doesn't help and Chinese made a copy without the service manual. Actually, the best way to keep distance vs competitors is the continuously improve a product.
Hi Duke, thank you for your valuable insights.
Just out of curiosity, who is Bruce?
Bruce Hofer is the founder of AP. He worked at Tektronix before, on their AAs.
Considering that R+S are out of the AA game (were it profitable, they'd still be in it) amd Aver Labs (ex-AP staff) recently folded, I don't think it's a particularly lucrative niche within the audio sphere. To have your IP shamelessly plagiarised in the manner AP is experiencing with this firm, is beyond the pale.
Considering that R+S are out of the AA game (were it profitable, they'd still be in it) amd Aver Labs (ex-AP staff) recently folded, I don't think it's a particularly lucrative niche within the audio sphere. To have your IP shamelessly plagiarised in the manner AP is experiencing with this firm, is beyond the pale.
I've personally worked with a chinese SYS27xx copy, it actually took me a while to notice it was not an original:
https://www.audiosciencereview.com/...s-of-sabaj-d5-dac-amp.8337/page-6#post-211348
https://www.audiosciencereview.com/...s-of-sabaj-d5-dac-amp.8337/page-6#post-211348
oh, I saw that old type of fake as well, made by the same company in Dongguan.
I visited them 4 years ago, they sold me some old original SYS2222 or similar, modified to be like SYS2702, $3000. They offered me fake APx525 but I had no interest.
As already noted, you usually see the 192K on the bezel of such equipped units. The other thing you will note is that the bezel is black on the 2700 series, not gray.
We saw a few copies pop up during my tenure at AP (I left six years ago). These weren't calibrated units and they would frequently break down. If you try to run genuine AP software on them, the units will brick.
I was the only former AP guy at Avermetrics. I joined well after they started. We came out with a really neat low cost box for production testing of line-level stuff. Unfortunately, the software never matured before funding ran out. A lot of the hardware capabilities never became accessible through the UI.
Echo Test & Measurement (formerly Echo Digital) has some really neat boxes that now fill the Avermetrics niche. They just make the hardware and allow you to use any 3rd party software such as REW or APx-Flex. They are being used in factories all over Asia. www.echotm.com. They have a former AP guy running their sales.