they discontinued the 402x in 2010 or so, but they had been DPA for 15 years or so at that point
were all the failures from B&K branded gear?
seems like its a known issue that was fixed since the modular series arrived in 2011, at least?
Well, both labels, B&K and DPA, actually. But they are the same manufacturer. It becomes a difference in the marketing end, regarding whether it is for a retail sale (DPA), or, commercial measurement device (B&K).
I'm not entirely familiar with the timeline anymore. My issues arose mostly in the 2001->2010 period, but, do reach back to 1989, when they first released the 4011, as B&K. That early 4011 pair failed in the same way that every other pair that I've worked with have failed. You get scratchy static, and then a 6dB drop in output, along with spiking of the signal. If you try to correct for the level drop, you bring up all of the junk that the failure presents in the signal chain.
I became quite close with Bruce Myers during that time. He treated me like their finest customer. They were absolutely top notch in the way that they handled each situation. But, ultimately, I could not reckon with having such an investment, that I could not trust.
Since that time, I've been entirely thrilled with my Line Audio CM3 sub-card pair, which, I feel, are equivalent to DPA, and, at something like $3.5k+ less
edit: really big fingers.