I was picking up radio on the ribbon mic’s pre-amp, at really high amplification gain. Ribbon mics need tremendous gain, because the base signal is so low, which meant this mattered. It wasn’t enough to appear in most – emphasis on most – recording situations, but I didn’t want it at all, because it indicates a potential circuit problem.

For the record, you start listening to EMF noise boosted by 96 to 142db (from extremely low levels), and you start chasing some serious fuckin’ ghosts. Somebody get me a skiffy channel show, stat.

Anyway, earlier in the day, I’d gone through all my patch cables, isolating the most RF-tight via comparative testing. It was a pretty big range. But even the best ones were still picking up some of that radio sound, and with some work, I could get it in clearly – tho’ always at extremely low levels.

Now, before I set about finding my best patch cables, I’d isolated out the microphone connection, to reduce complexity and eliminate other noise sources.

This is called a Null Signal Wire.

Turns out, a 3mm run of unshielded null signal wire can bring up a surprisingly durable amount of RF, in the form of BBC World Service on shortwave. Pulled that back out, popped in a microphone cable (connected to the ribbon mic): no more radio.

The goofy thing is that Cascadia is notorious for shitty shortwave reception. I can’t get BBC World Service reliably on my shortwave radio. AND YET.

At least it’s sorted, now. I still need to evaluate a few more cables, but the explanation is in hand, and that’s the important thing.