QA403 dimensions

Hello All,

Just joined the forum hoping to learn more about the QA products.

As I await my QA403 order, I was wondering what the overall dimensions of the unit are?

My plan is to rack mount this unit maybe as a half-rack wide unit.

All my test equipment is rack mounted and the QA403 should look nice mixed in with the likes of HP, Krohn-Hite and Bruel & Kjaer.


Hi Arkytype. Front panel: mm 177 x 45; dep: mm 97 (excluding BNC). At this link you will find all the electrical and mechanical characteristics

Thanx, Claudio. I should have read the product specs a little closer.

Good morning, Claudio,

Thanks again for the info.

Do you own one of the QA40x variants & if so, what measurements do you perform?



Hi Lee. Yes I own a QA403 and you can do many measurements with it. All the possible measurements that a spectrum analyzer can do the QA403 does. Just a few I mention: frequency response; THD; THD+N; Noise; Intermodulation distortion; frequency-dependent distortion measurements; power-dependent distortion measurement and/ or voltage-dependent distortion measurement; measurements on loudspeakers and many more that I won’t mention here. The QA403 can be paired quite easily with a Notch Filter in order to extend its distortion measurement capabilities. But you can find an overview of what the QA40x can do on the blog at this link: Blog Entries – QuantAsylum

Hello Claudio,

Thanks for info.

My interests include repairing test equipment and acoustical measurements.

As you can see from the image I have a mix of old-school gear as well as current tech stuff. The “clutter” is normal it seems!

While the QA403 can certainly replace much of the functionality of my present gear, it will be none the less useful.



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Very nice bench!!! A plotter even unless my eyes deceive me

Hello Scott,

Thanks for the kudos. The left X-Y plotter is a version of the HP 7010B offered without the “front end” and was sold by UREI as the Model 200. They made three innovative plug ins.

This particular unit was purchased from the estate of the late audio equipment reviewer, Julian Hirsch. He purchased this unit in the mid-'70s as a replacement for a General Radio plotter (1521B?) that could no longer be maintained.

The right X-Y plotter is a Bruel & Kjaer 2308, a versatile unit that can control other B&K instruments to perform frequency response plots. The plotter pens are no longer sold by B&K; I paid $200+ for a set of six 15-20 years ago!

Sure, most of the gear is old school, but everything works and meets or exceeds the original specs.

What gear do you operate & what measurements do you perform?



I grew up with HP plotters, from the two to the 6pen units. Using static energy to hold the paper down- been a few years since I saw one operate in person. I remember reading Julian Hirsh in Stereo Review i think it was, for many years. Bet you can still get the plotter pens for the HP units, though probably a bit pricey. I have a lot less testing gear. main thing I use is the QA402 and a few DMM’s. I got an $80 Zotech DMM/scope which I like using for certain troubleshooting. I started a YouTube Channel where I measure/review (and sometimes repair) older “vintage” audio gear. I will post a link to one of my videos that shows my bench, part of it and what I am doing in my retirement. No plotters and not nearly as much neat stuff. It would be nice to have a few pieces of Sencore audio test equipment, but those will have to wait until I find a deal on them…

McIntosh C22 Tube Preamplifier- Vintage Audio Review Episode #78 - YouTube

Hey Scott,

Can you PM me @ my Email address?