Apologies if this has been posted elsewhere, I haven't seen it. From the QA401 webpage:
Bad news indeed, I went there to order one...
Bad news indeed, I went there to order one...
I guess I'd sell on a first-come first-served basis. Maybe limit the order quantities. But it's their business, and they are free to handle things their way. I just said that I don't like it, that's all.
I'm new to diy audio, and bought a QA401 recently (while still available) for fun and learning. Since the client software is only available for Windows I spent some time making a web interface for the QA401H rest api that works on Linux and Mac as well.
Hope it's ok to post it here, but it's open source, so I make it available in case anyone finds it useful, even if just for the sake of seeing an example of how the api can be used.
GitHub - blurpy/qa401w: Unofficial web interface for QA401 Audio Analyzer
Since I am new to measurements I've probably made mistakes somewhere, so feel free to let me know and I'll try to fix it.
Hope it's ok to post it here, but it's open source, so I make it available in case anyone finds it useful, even if just for the sake of seeing an example of how the api can be used.
GitHub - blurpy/qa401w: Unofficial web interface for QA401 Audio Analyzer
Since I am new to measurements I've probably made mistakes somewhere, so feel free to let me know and I'll try to fix it.
I'm sure they've done the numbers: keep existing business customers happy, lose potential new ones who can't wait for a new product to be released and will look elsewhere... Not me, to be honest: I'm a DIYer, I'm not in a hurry and will wait patiently for whatever they release next, since there aren't many alternatives that can compete in terms of price / performance / ease of a simple, plug and play hardware + software package. In the end it may be a good thing if they use newer and better chips and, as you would expect, a more attractive feature set vs. the now sadly and suddenly obsolete 401. I also hope that they will take advantage of having a reasonably large user base who can give very useful feedback for improvements, new features, etc. I guess we'll see...
I think that's right. Experimenters are not their core business, nor should they be. DIY practitioners *might* buy one unit, if that. On the other hand, there's lots of small to medium sized companies who'd buy these by the dozen for production testing. You can see that based on the rest of QuantAsylum's product line - loads for fast amplifier testing, gear for testing IEM's and so on. Supporting their main customers who rely on QA products for their own production makes perfect sense.
Plus, keep in mind that a somewhat higher priced alternative has gone away, presumably because of business reasons. (Avermetrics | Test And Measurement) Audio Precision products are the industry standard, but are pretty much out of the reach of most experimenters. Certainly out of my reach.
I'd guess that QA is working hard on a Plan B. The event at AKM was hardly something they could expect. The good news is that better converters, at least on the ADC side, have been announced. Perhaps an even better product will emerge from QA sooner than might have otherwise happened.
Plus, keep in mind that a somewhat higher priced alternative has gone away, presumably because of business reasons. (Avermetrics | Test And Measurement) Audio Precision products are the industry standard, but are pretty much out of the reach of most experimenters. Certainly out of my reach.
I'd guess that QA is working hard on a Plan B. The event at AKM was hardly something they could expect. The good news is that better converters, at least on the ADC side, have been announced. Perhaps an even better product will emerge from QA sooner than might have otherwise happened.
I wrote a post on the current status of the QA402 last week.
Sneak Peek: The QA402
– QuantAsylum
When the news of the AKM fire hit, it required a change to the converters used in the QA402. TI were chosen because the performance is really good and the confidence is high they'll be here in 5 years. In any case, the first boards with the TI converters came back last week and some early measurements are shared in the post above.
Sneak Peek: The QA402
– QuantAsylum
When the news of the AKM fire hit, it required a change to the converters used in the QA402. TI were chosen because the performance is really good and the confidence is high they'll be here in 5 years. In any case, the first boards with the TI converters came back last week and some early measurements are shared in the post above.
Hi Matt,
That is a great post on the coming QA402. Thanks for the sneak peek. It looks like serious improvements have been made to an already-wonderful product.
It is really sad about AKM. They probably have lost a good amount of their footing, as numerous clients like you will be forced away from the AKM products and may not come back unless there is really strong incentive.
The CMOS OPA 1656 is a remarkable product. I at first had trouble believing it was really in CMOS. I don't recall seeing the term CMOS on the datasheet. There is one thing about this part that we must bear in mind. That is 1/f noise. That is not unusual for any CMOS process as compared to a JFET process. The 1/f noise corner is pretty far up in frequency, and the touted 2.9 nV/rt Hz is not reached until about 10 kHz. It is a wonderful and remarkable part, make no mistake. We just need to be aware of its 1/f noise behavior.
Thanks again for the QA402 update and your constant effort on improving existing products and coming up with great new little red box products.
Cheers,
Bob
Great post! I'm really excited to see that the OPA1656 made it into the QA402 (for now at least). The OPA1656 was a labor of love for me and several others on the team, and it's always great to see where our amplifiers end up once we send them out into the world. I can't wait until I can add a QA402 to my home lab!
Looks like a great product yet again. Did you look into the Cirrus converters like CS43198 and CS5381 also?
The OPA1656 is a very good choice. There are no better ones right now. The LM4562 should also be mentioned. Both chips are very good at low source impedances (THD / THD + N), but the OPA falls behind at high source impedances.
For the DAC/ADC I would have preferred an ES9038PRO chip. They are the top reference at the moment.
For the DAC/ADC I would have preferred an ES9038PRO chip. They are the top reference at the moment.
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Agree. As an own of QA401....
Matt, if you are gonna make a new design=QA402, please please don't use PCM1794!
ES9038PRO is great, fantastic, but if the price is the issue, you can consider 9038Q2M.
PCM1794: THD+N=-107dB, DNR=132dB(max), $7.7 for 2K+ pcs
ES9038Q2M: THD+N=-120dB, DNR=128dB, $12 for 100+ pcs (surely lower than 12US for 2K+)
So, I think they're basically the same class competitors. For sure TI is a good supplyer with good reliability, so is ESS. PCM4220 is awesome for sure, but PCM1794 isn't, it's kinda old-fashioned. The performance of 9038Q2M is a bit better than 1794, but aside from measurement, if one uses QA402 as an audio DAC, 9038Q2M has better soundstage and its ESS-specific resolution; definately 9038Q2M is better than 1794, it's good for performance and listening experience.
As an owner of QA401, I will definitely get another QA402 if the DAC is ES series!
Also, from the lesson learned with AKM's fire, isn't it reasonable to use parts that 2 different suppliers? In this case, choosing TI and ESS seems to be an excellent decision.