TRS plug for Sennheisser into Zoom H2?
 

I was planning on ordering an Oscar Soundtech lav mic with the intention of feeding it into a Zoom H2. The only 1/8 plug they have is the TRS plug for Sennheisser. Will that be compatible with the Zoom H2, H1, et. al.?

I got a reply back from the company:

"I just called one of our Engineers, he confirmed that 1/8" mini-jack is the same as the one used for Senn. The full name is 1/8" (3.5 mm) TRS plug with locking."

I think I will give these a try. Hopefully the Zoom H2 mic plug-in power is sufficient? These mics have an interesting reputation on the jwsound's forum -- reportedly they sound as good as other lavs two to four times the price.

It's the same physical plug but the wiring is probably different. The 1/8 plug going into the Senn transmitter, thus on your mic, is wired for an unbalanced mono mic, with tip being signal, sleeve ground, and ring shorted to sleeve. The Zoom's external mic jack is wired for unbalanced stereo mics with tip being left signal, ring being right signal, and sleeve being ground. If it works at all, you'll only have audio on the left channel in the Zoom's recording.

You may also find the locking ring is a problem with the H2 1/8 jack socket. Sometimes the ring gets a bit stuck if there'e no locking thread on the socket and prevents the plug going fully in. Better with a normal 1/8 plug but it will have to be correctly wired.

As for power, the Zoom H2 manual says
whereas the specs of the OST-801/802 Lavalier microphones say the Supply Voltage is 1.3 V with the TL- 40 being a nominal 1.2 V. Again as Steve says, the Zoom is expecting a stereo mic and it won't supply power if the cable isn't correctly wired for it.

I'd just buy the plug and once you've established the correct wiring, just solder it on. A quick voltmeter check will show if the polarising voltage is on both tip and ring, and then if so, you can connect the one mic to both l and r if that's what you fancy. All you need is the info from the mic manufacturer on how many cores - could be screen, audio and voltage, or just screen and combined audio and polarising voltage. I'd suggest that putting a plug on yourself is the only simple way of doing this as the manufacturer is a bit vague.

Thank you everyone for the additional clarity and warnings about the potential incompatibility.

I received an additional email as well from the company (best pre-order customer service of my life) where they stated:

"Our technical staff has looked at the Zoom H2 briefly. To clarify, our mic is not stereo and I believe you are going to connect it to the external MIC input of the recorder.

As stated in H2 user manual, "To use an external mic for recording, connect the mic to the [EXT MIC IN] jack. If a mono mic is used, only the left channel signal will be recorded."

Our 1/8" locking is designed specifically for Senn., which may cause some contact issue if the physical dimensions are not perfectly matched.

Therefore we will wire it with a mono 1/8" mini-jack with no Lock."

The OST mics will work with the H2, however the H2 mic pres' are not exactly what I would call "stellar", so when possible, use a quality external pre-amp and the H2's line-in jack, which is -10dB.. +4 will overdrive the input stage!)

That said.. when using the TecNec 3.5mm plug that OST supplies, the locking ring recedes enough for the plug to be fully inserted. On the 'Sennheiser' configuration, the ring connector is floated, so the audio will only record to one channel. (left) To record to both of the channels, the H2's 'Mono mix' may be engaged in the software menu. Unfortunately the H2 does not have 'Mono file' mode like the Marantz portable DARs,
Be aware, the H2's Plug-in power must be switched on via the software menu. .. unlike most recorders, where it is always present.

Addendum: I should point out, when using the 'Mono mix' mode, having no signal and an open connection to the right channel may add additional noise.
Otherwise It's easy to remove an unused stereo right channel of a clip in most NLEs.