QA404 Release Date?

Just wondering if you can project a date on which we can order the QA404. I’ve been waiting patiently.

Hi @ScottRichardson, it’s hard to know at this point. It’s important to remember how we got here…for 5 years, we kept the analyzers in stock. Then came the AKM fire, and then came the huge silicon shortage. The shortage hit a few parts from TI really hard and that killed the QA403. The QA404 was in response to that, because the QA404 tried to reduce the number of parts that depended on TI. But then, things started easing, and all the parts that had been ordered for the QA403 starting arriving. And in some cases, we have nearly 10,000 of a particular part!. So, with the QA403 starting to ship again (albeit in fits and spurts, which is getting resolved) that has taken some of the pressure off the QA404.

The QA404 added the SPDIF to the front panel. But with the pressure relieved somewhat, we’ve gone back and re-visiting the ability to get more protection on the 8 front panel inputs and outputs (the input protection on the QA403 and its predecessors is pretty good up to about +/- 50V with atten off, and much much more with atten on). What is in place on the QA404 currently is an array of 8 400V solid state relays, along with a logic that can detect overvoltage situations on any of the inputs or outputs and turn off the relays in about 200uS. So, if you have a probe on the QA404 OUTPUT in an attempt to inject a signal into a circuit, and you accidentally touch it to a 100V supply, the goal is for the output stage to survive. You can see the relays (blue arrows) in the current QA404 hardware below.

PS. Previously, a fair bit of study was done with back to back depletion mode devices. On the input, they worked well at lower levels but as input levels increased, they’d start to turn on and the distortion would rise and a fair bit of effort was spent trying to control the turn-on. And on the output, if you were driving anything other than high-impedances, you’d face the same issue–they’d start to turn on and distortion would increase.

In any case, I don’t currently know when the QA404 will be ready. It won’t be in the next 3 months for sure. I really want the increased IO protection.

I guess I’ll have to be patient and wait for the email notification of availability. I’m signed up for the list. Thanks for the explanation.