Audio Precision System Sys1 USB Interface

you said : "If you can't measure an improvement how do you really know that you've improved anything?"

My problem with APs is : can they detect "anything" ?

For instance, if you improve the phase noise of an oscillator somewhere in the digital chain,
an AP can detect that ?
 
For instance, if you improve the phase noise of an oscillator somewhere in the digital chain,
an AP can detect that ?
Maybe by measuring phase shift and/or phase noise? That's simple with an AP. How would you do it, with a multimeter?

You have a very strange idea about an AP.
It's a measuring equipment. It can do all sorts of measurements that are hard or impossible to do with other equipment, and as such is very valuable for serious designers. It is too expensive for most diy-ers, but then again most diy-ers are not interested in the details of designs either.
To each his/hers own.

Edit: maybe you are confused because you don't see any knobs or meters on the AP box. That is because it is all controlled from software.
Download and install the software and run it in demo mode. Or read the user manual.
Your life will never be the same again 😎 and you will no longer ask these strange questions here!

Jan
 

Attachments

  • Capture.PNG
    Capture.PNG
    20.9 KB · Views: 132
inguick Cable question. I need to calibrate my S1 and I know it has to be done connected to a PC running the DOS S1.EXE with an AP card not the USB adapter. I have an old PC with the AP ISA card. Is the cable from the card to the S1 just straight thought DB25?
 
inguick Cable question. I need to calibrate my S1 and I know it has to be done connected to a PC running the DOS S1.EXE with an AP card not the USB adapter. I have an old PC with the AP ISA card. Is the cable from the card to the S1 just straight thought DB25?
DB25 connector at each end all pins. This works fine. Let us know how your calibration goes. I have not been able to get the software to run on my recent machines under DOS.
 
hi Jan,
an AP is quite pricey isn't ? how did you paid for your AP ?

THanks for your joke about a "multimeter" 🙂
but what about a VNA ?
I did pay for it by working to make money. Used AP's are affordable for many, if you really want one.

Do you have a suggestion for a VNA that can be used at audio frequencies? I'd be interested in that.

Jan
 
Last edited:
I did pay for it by working to make money. Used AP's are affordable for many, if you really want one.

Do you have a suggestion for a VNA that can be used at audio frequencies? I'd be interested in that.

Jan
Hi Jan, a serious answer could be the HP 3577A or B. The A is nicer in that it always has the OCXO.
But for (automated) audio performance tests i know of nothing better suited than an AP.
 
Last edited:
  • Like
Reactions: jan.didden
Greetings all,

I have an Ap Sys1, but of course lack the APIB device. I have tried to contact both Duke Aguiar and Udo, both without success.

Does anyone have an interface available for sale? I would much prefer the USB version, but would consider anything else available.

Thank you,

Bob
 
Hi Bob:

I have both ap interface cards. The ISA card (top board) only works with DOS version (S1.EXE). The PCI card (Bottom card) works with windows version of ap software. The AP interconnect cable is included.
You need to have a pc mother board with PCI slot.

Asking price for the APIB PCI card with cable is $600.00

Art
 

Attachments

  • IMG_0320.jpg
    IMG_0320.jpg
    644.4 KB · Views: 82
Thanks Duke,
I did order one and will give it a try. Say, is there any chance that you might have a copy of the Portable Plus One Access service manual? Or know where i could find one? My unit is just slightly off in the amplitude self tests and there is no one in europe who can calibrate these.