#664a

These mics all share the same capsule with the RE15: RE10, RE11, PL11, RE16, RE18, 660/660A, 664A, 419, and PL6. There may be more, but these are the ones I know of. (Contrary to what you read online, and to its resemblance to the RE16, the DS35/PL95A does not have the same capsule as the aforementioned mics. It’s a completely different design, for a different application.)

The RE10 is identical to the RE15, but had looser unit-to-unit capsule tolerances. The RE16 is an RE15 but with a different headbasket wrapped in tons of foam to get rid of plosives. The RE11 and PL11 are the same, and similarly are just RE16s with looser capsule QC. The 660/660A and PL6 are the same, and identical to the RE15 except for a wider/tapered barrel (cast zinc instead of steel), no low-cut switch, and an optional high-impedance output via a transformer. The 664A (not the original 664!) is identical to the 660 but with a pivoting base & on-off switch. Confused yet?

All of these mics have the same capsule, same ‘supercardioid’ pattern with the same smoothly-sloping off-axis response, the same Variable-D venting to reduce proximity effect, and the same ‘nested’ construction with the same side vents. They also all have the same resonator in front of the capsule, except for the RE16, which is slightly different (to support the foam/headbasket).

So, if you’re interested in an RE15 but don’t have $300 to spend, what are your options? Some people get RE16s and remove the foam to make them more like an RE15. I tried that, but I found that you can get closer by grabbing a 660, PL6, or 664A, and removing the transformer. (Note that the original 664 has a different capsule/resonator and rolls off a lot of low end. The 664A looks like a 660 on a 664 base, because that’s what it is. The 419 is a 664A with a momentary-switch base.) You can remove the base of the 664A and install its XLR plug into the handle, making it a 660. Cut out the transformer and wire the capsule directly to the XLR plug (red to pin 2, white to pin 3, case/chassis to pin 1) and you’ve basically got a funny-shaped RE15 with no low-cut switch. Check out this FR plot of a distorted guitar cab, re-amped:

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Notice how incredibly close all these mics are to each other, but more than that, how the modified 664A is closer to the RE15 than either the stock RE16 or the foam-less RE16! The 660/PL6 will perform equally well, just be sure that the transformer is removed or you’ve wired them for low-Z mode. In this test, the RE15 had just a hair more low end than the other mics, but it’s within a dB or two. In other words, you’re likely to find as much difference between any two RE15s of different ages as you will between the average RE15 and the average 660/PL6/664A/419.

I regularly see 660s go for around $100-120, and 664As for less than $100. At that price, they’re a steal. Even better, they fit in a tapered SM57-style clip (the RE15/16 don’t).

I bring up the DS35/PL95A here because I like them a lot, and they’re still cheap, but they seem to be mostly unknown and subject to a lot of misinformation online. I frequently see people saying they have the same capsule as the RE15/16. The DS35/PL95A (same mic, different paint) look like an RE16, but they are a different design with a different capsule. The intended application was as a handheld ‘runway’ mic, where the main priorities were side rejection and resistance to handling noise and plosives. It does not have Variable-D venting, and the capsule is loose in the headbasket and sits in a pneumatic shockmount. Despite being a ‘cardioid’ mic, its pattern is in fact much narrower than the RE15/16 and derivatives, and its handling noise is orders of magnitude lower. It’s also brighter, and basically immune to plosives. It’s a sleeper vocal mic for sure, but beware that its sensitivity is much lower, around 0.8mV/Pa (although this varies unit to unit). You might need a Cloudlifter for vocal use. I also like it on snare, hi-hat, and guitar cabs. Check out the DS35′s response versus the RE15/16:

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