Anyone using the QuantAsylum QA403?

saabracer23

saabracer23

Super Member
I just ordered this analyzer about a week ago along with a QA451 4/8 ohm load. Any tip and tricks I should know about? What’s the best method of hooking it up to my laptop? I read that you need a good sound card or a USB interface like the Focusrite Scarlett?

Thank you,
Dan
 
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saabracer23 said:
I just ordered this analyzer about a week ago along with a QA451 4/8 ohm load. Any tip and tricks I should know about? What’s the best method of hooking it up to my laptop? I read that you need a good sound card or a USB interface like the Focusrite Scarlett?

Thank you,
Dan
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Dan, you shouldn't need any soundcard at all.
 
saabracer23 said:
Someone said that I should grab a Focusrite Scarlett USB interface to use with it, does that make sense?
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No.
The focusrite is a low cost solution if you want to use freeware like REW. I've got the focusrite, dummy loads, need to upskill on the SW.
The QA403 has better noise figures etc and is a standalone solution(HW&SW), envious of your purchase.
 
i had one. no sound card needed. i would return the qa451 and build your own dummy load. its designed for automated testing and can only handle short bursts of power, not ideal for most people on this site imo. if you do keep the qa451 read the manual carefully
 
pac1085 said:
i had one. no sound card needed. i would return the qa451 and build your own dummy load. its designed for automated testing and can only handle short bursts of power, not ideal for most people on this site imo. if you do keep the qa451 read the manual carefully
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I appreciate your input. You say you had one, did you get rid of it? If so, any particular reason why?

I’ll read the manual for the 451 carefully and I guess return it if need be. I have a set of 1000w dummy loads currently (1000w at 8 and 2000w at 4), the reason I grabbed the 451 was because I was reading where a guy was building some decent powered class A amplifiers and it helped with the measurements.

Is it anything other than a simple dummy load? Basically a set of resistors hooked up to some BNC connectors?

Edit: I’ll have to do some more reading and playing with it I guess. I do appreciate that it says that the internal load can be bypassed and you can wire in your own dummy loads. It has other features which I don’t understand at the moment with attenuating the signal, converting balanced and single ended, and benefits to measuring class D amplifiers. Never ending learning.

Dan
 
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saabracer23 said:
I appreciate your input. You say you had one, did you get rid of it? If so, any particular reason why?

I’ll read the manual for the 451 carefully and I guess return it if need be. I have a set of 1000w dummy loads currently (1000w at 8 and 2000w at 4), the reason I grabbed the 451 was because I was reading where a guy was building some decent powered class A amplifiers and it helped with the measurements.

Is it anything other than a simple dummy load? Basically a set of resistors hooked up to some BNC connectors?

Dan
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I have a Panasonic vp-7725d, I bought the qa403 because I thought the automated measurements like power vs distortion etc to create nice plots would be cool to have, but I really didn’t like their software.. I’m using gpib with my current analyzer to get what I want instead

The qa451 can only handle power for milliseconds at a time.
A regular resistor dummy load works fine with the qa403
 
pac1085 said:
I have a Panasonic vp-7725d, I bought the qa403 because I thought the automated measurements like power vs distortion etc to create nice plots would be cool to have, but I really didn’t like their software.. I’m using gpib with my current analyzer to get what I want instead

The qa451 can only handle power for milliseconds at a time.
A regular resistor dummy load works fine with the qa403
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Oh yes very nice. I was looking at that exact Panasonic, but unless you wanted to take your chances on an unknown condition or one with a dying screen you’d be looking at quite a bit more than the QA403 itself, multiple times more. If I had the money I would have gone for it as I’d much prefer an all in one unit, meaning screen and all. It’s crazy what test equipment sells for, analyzers costing more than houses in some parts of the country. Oh well, I’ll have to get used to their software I guess. I’m sure once I learn it I’ll be pleased, but maybe if a nicely priced Panasonic or similar crosses my path I’ll grab it.

Dan
 
saabracer23 said:
Oh yes very nice. I was looking at that exact Panasonic, but unless you wanted to take your chances on an unknown condition or one with a dying screen you’d be looking at quite a bit more than the QA403 itself, multiple times more. If I had the money I would have gone for it as I’d much prefer an all in one unit, meaning screen and all. It’s crazy what test equipment sells for, analyzers costing more than houses in some parts of the country. Oh well, I’ll have to get used to their software I guess. I’m sure once I learn it I’ll be pleased, but maybe if a nicely priced Panasonic or similar crosses my path I’ll grab it.

Dan
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I was contacted by a guy that saw the VP-7725 on a video I did. He bought several from out of the country. He found that the screens are easily found, and are about $22 on Alibaba. Pac1085 knows him and saw a pic of the new screen, and based on his commentary I may buy one too.

I think you'll be pleased with the Quantasylum. @Steven Tate has an older one, and it's worked well for him.

The sky's the limit with test equipment.
 
Ray Gianelli said:
I was contacted by a guy that saw the VP-7725 on a video I did. He bought several from out of the country. He found that the screens are easily found, and are about $22 on Alibaba. Pac1085 knows him and saw a pic of the new screen, and based on his commentary I may buy one too.

I think you'll be pleased with the Quantasylum. @Steven Tate has an older one, and it's worked well for him.

The sky's the limit with test equipment.
Click to expand...

Oh wow, that’s awesome to know. Maybe I can snag one up with a bad screen. Do you have a YouTube channel? I’d like to check it out if so.

Dan
 
Their software works great for
saabracer23 said:
Oh yes very nice. I was looking at that exact Panasonic, but unless you wanted to take your chances on an unknown condition or one with a dying screen you’d be looking at quite a bit more than the QA403 itself, multiple times more. If I had the money I would have gone for it as I’d much prefer an all in one unit, meaning screen and all. It’s crazy what test equipment sells for, analyzers costing more than houses in some parts of the country. Oh well, I’ll have to get used to their software I guess. I’m sure once I learn it I’ll be pleased, but maybe if a nicely priced Panasonic or similar crosses my path I’ll grab it.

Dan
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Sorry for the short replies, been on a 10 hour road trip today picking up a hp 3585 spectrum analyzer, lol

qa403 is the better option honestly, mostly for the reasons you mentioned, unless you absolutely need the lower distortion capabilities of the Panasonic. if I didn’t already have the Panasonic it would be a no-brainer. In my case it just wasn’t worth keeping vs what I already had since I would have had to write custom code to do what I want, with either device (I wrongly assumed that the software for the qa403 was a little more flexible when it came to automation, it sorta is but you’d still have to write your own code).

For basic measurements, like dist+n, thd, snr, etc, the qa403 is just as useful as the Panasonic right out of the box. Plus you get the fft display. I have to use my hp dynamic signal analyzer if I want that.

Can’t beat the size of the thing, either…
 
The QA403 negates the need for a soundcard. It is self-contained with a DAC and a tone generator, and you use the supplied application for your measurements and analysis.
You'll need BNC cables, RCA adapters, 50 or 75 Ohm BNC terminations.
Also, download the manual, and read the WIKI page - each are linked on the QA web site.
In testing mode, the QA403 produces bursts from the generator when in test mode, which is why the QA451 is not a problem to use for testing, but if you select the idle feature, it outputs continuous tones, so you do want to read the manuals carefully.
If you have this unit, you will probably get better results and much more easily than the REW/soundcard/generator approach - that has been my experience, at least.
I have an HP339A, HP8903B, Amber, and Sound Technology distortion analyzers, as well as the QA403, a soundcard, and the Cosmos system. Of all, the standalone HP are easiest to use and accurate, but performance is not as high as the QA403 or Cosmos. I use them for older audio gear, and for fast measurements to confirm proper operation, rather than fully characterize (to my abilities) the DUT. The Cosmos is quieter than the QA403, but a true pain in the butt to use, as the documentation is nonexistent.
Figure out what you want to measure and the end goal of the measurements, and pick the right gear. You are probably there already. Keep them both and also make a good, noninductive dummy load for when you need it.
 
It seems that even though it was said that there were be a possibility of availability in the first week of December, I guess there wasn’t. Either that or they sold out quickly. I contacted QuantAsylum last week and placed the order over a week ago and it’s radio silence. Other than a confirmation of my order. The waiting game…

Literally just got an email. Said Sealig will be out until late Jan, but since I ordered through them I could get it sooner. Asked if I was going to be home this week! Here’s to hoping!


Dan
 
Ray Gianelli said:
I got a thread deleted because I mentioned my youtube channel. You can find me on there if you look.
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I remember that Ray, and I also really don't understand why that would have happened. Especially when there are so many other members putting up links to their youtube channels....

Just to say, I really enjoy your content, and you do a fine job as a host.

Cheers mate,

Art
 
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