Both capsules have to be insulated from the body of the mic. The front capsule would create a ground loop and the rear capsule has to be able to be “reversed”.

I used leftover bits of bare wire to suspend the capsules from the switch terminals on one side and an elastic hair band on the other side.

The mic circuit is the original one with an

added 470Ω resistor and 220 uF/35V filter cap after the voltage regulator transistor, and the output wiring to pins 2 and 3 swapped to make the mic’s phase match the studio standard. Details of modifying these Chinese electrets are found here.

Except for dealing with SMT resistors the size of beach sand, this isn’t all that complicated. It would be great if we didn’t have to use the OEM circuit board, but the space in the handle of these mics is very limited, and it would be hard to fit through-hole parts. It also pretty much eliminates using these E-1000 bodies with non-electret capsules.

On to results, then. Measurements and sound. The unique feature is an electret with a Fig-8 pattern. The frequency response isn’t ideally flat because the capsules aren’t perfectly aligned, but it sounds fine, and sound pickup to the sides is dead, which is one of the main reasons for using Fig-8.

First cardioid. Red mic#1, Green mic#2. Pretty flat and very extended top end. Some LF roll-off.

Omnidirectional. Red mic#1, Green mic#2. Smooth with extended top end. Some LF roll-off.

Figure 8 pattern. Red mic#1, Green mic#2. Pretty flat with a dip around the sibilant frequencies.

Some LF roll-off. Importantly, the side null is very deep. You can aim the side at something you DON’T want to pick up.

My guess is these are going to be very good for ballad vocals and acoustic stringed instruments. Maybe drum overheads, but probably not so hot for close-miking loud sounds. They are fairly hot, high output mics without any attenuators, and the JFET isn’t biased for high levels. But who knows, they might get crunchy in a useful way for the right song. Time will tell. They sound “real” and “intimate”. Probably not a universal mic, but a nice addition to the arsenal.

Here’s the test sequence.

The hammer dulcimer and mbira are quite close-up. The sax is centered and breathy.

Male and female vocals are intimate.

Synth is thin and over-bright.

If you had meters on the levels, you noticed the white noise was same level as A440, but pink noise was several dB down.

Car that drove past during sax solo wasn’t obtrusive, but A/C can be heard, so cardioid pattern is pretty good (traffic is to mics’ rear).