Audio precision help choose

[Stefanoo]

Hi everybody,

I need some help here.
I would be interested in the audio precision system one 222G + dsp with almost full options.
Then I called Ap and they discouraged me from getting this one because of the age, plus gpib port won't allow me to use the ApWin sw only with an additional $650 extra interface; plus they told me that if the dsp goes down which is very possible I can kiss goodbye to the instrument.
They rather suggest the analogue version.
But I am interested on a precise, flexible instrument pc interfaceble where I can plot graphs elaborate data and stuff.
So they suggestede to get the apx515 or something like that.
The only problem is that this instrument is a little over budget (6.2k).

I would like to know from users of Ap what are some thoughts in this regard and how they evaluate Ap system one with gpib port.
I am not set with gpib interface nor have I ever work or play around with one.

Any suggestion will be very welcome.

For now I am using the sound technology 1700B with the external low noise/distortion signal generator and a nice sound card to interface the FFT of the signal but I wouldn't disregard having just one compact, flexible and precise machine.

Thanks everybody for your attention.

[jackinnj]

You can get the new Stanford Research audio analyzer pretty close to your budget.

Audio Analyzer - SR1

SRI is very highly regarded for their scientific and measurement equipment. I think Janneman saw the SR1 in action at a trade show.

[abraxalito]

Looks like they built a PC motherboard (or industrial variant) inside that case. Wonder if they could have done it without the PC in the same manner as Ap? Might have reduced the price a little.

[jackinnj]

I erred on the price, was different when they first came out.

It would be nice to be able to escape the AP Macro's for certain tests -- you can write your own in the AP language, but the full range of instrument control in the SR1 is available in VB owing to the Windows platform.

[Stefanoo]

The instrument you linked is really nice but overbudget with the options and not.

Perhaps more feedback on system one would be useful.

[janneman]

Originally Posted by Stefanoo

The instrument you linked is really nice but overbudget with the options and not.

Perhaps more feedback on system one would be useful.

I have an AP S1 + DSP. It's a nice instrument but I would not buy it today. Hardware-wise I think it is still at least as good as an APx515; these are more production-oriented and not really the very highest resolution.

The AP S1 software is, to say the least, very user unfriendly and not up to speed with the modern instrumentation applications. It's a DOS port to windows and it's structure still is DOS-wise. Also, APWIN (which runs the AP S1) doesn't run on W7, doesn't run on 64bits systems and is no longer supported. Even if you get an S1 with the original APIB interface card you need a PCI slot so using it on a laptop is out. This is a good product but with dated h/w and s/w.

I would get the best soundcard you can get and a good analysis software.
The AP S1 works up to 200kHz and that's the weak point of a sound card; even with 192kHz sampling you'r limited to 90kHz analysis or so.

If I would have several $ 1000's to spend I would see if I can get an SR1. Alternatively, take a look at the LinearX LX700 system, which fills a middle ground.

jan didden

[Stefanoo]

Thank you very much for you input.
You have been really useful and precise.
I have 2 questions then

1) how much would it be a lx700 if I were to get one with same features of Ap 1 but up to date he and sw?

2) what is the BEST souncard you would recommend? I know it is limited to 90khz but if I can get reliable and calibrated results up to 90khz and precision up to 0.05db that would be all I need. Is it possible to have such a precision and low noise with a sound card? The biggest problem I found so far with soundcard system is the noise if the generator and dynamic range I.e. measurements are susceptible to in/out level. I have a low noise gen but if I would like to get a frequency response I would have to sweep it manually which is not feasible for time response and flat response of the generator especially if trying to measure a high gain device such as Phono stage.

[janneman]

[QUOTE=Stefanoo;2449491]Thank you very much for you input.
You have been really useful and precise.
I have 2 questions then

1) how much would it be a lx700 if I were to get one with same features of Ap 1 but up to date he and sw?[snip]QUOTE]

I don't know all the features but ask yourself: do you want to copy an AP or do you have specific requirements?
Just go through the LX700 module specs, built your system and see how mucu it cost. Do you need 1 or 2 generators? 1 or 2 analyzers? DSP? Do you need digital audio capability?

jan didden

[Stefanoo]

2 channels would be better.
100KHz bandwidht would be minimum requirement.
106-110dB S/N

Distortion floor <0.001%

I would like the PC interface capabilities to be able to see the FFT, frequency response, distortion along bandwidth.

no need for digital audio capabilities now.

I have looked through the LX and looks like it would cost over 6K to build something similar but I will double check that, so it would be pretty costly.


Can you tell me if you have any experience comparing your Ap system one with an high end soundcard based system?
If so, what are the main disadvantages and/or advantages you see usign a soundcard versus system one?

In that case what racommendation do you have for soundcard?


thanks.

[abraxalito]

With a soundcard as compared to an AP, you'll never be sure that the noise you're seeing is from the device you're testing rather than from the PC. That's because the AP has taken pains to build in isolation for its outputs. To make the best use of a soundcard, you'd need to have some kind of interface box providing the isolation if you hope to get repeatability at low levels. The soundcard would need balanced inputs and outputs to connect to this box.