Topic: Primo EM 172 balanced cable to Fostex FR2-LE I need advice, thanks!

[Schubida]

Hello,

first of all, please excuse my bad english.

In my next project I want to use a pair of  EM 172 mic capsuled I bought from "frogloggers" with my Fostex FR2-LE flash recorder via its XLR-inputs (balanced) in combination with the Soundprofessionals Y-adapter cable ( female 3,5 mm Neutrik minijack input to two XLR outputs with the phantompower converter option (48V to 5V)). Can you please give me advice  how to solder a balanced cable with two conductors and the shield to the two primo EM 172 caps and to the Neutrik male 3,5 mm minijack (in stereo configuration of course).

Thank you very much for your help!

All the best!

Wilhelm

Description of the SP-Converter cable: Sound Professionals Dual XLR Male to 1/8 inch Stereo Gold Plated Female with Phantom Power Converter Option (SP-XLRM-MINI-2)

[Roger Gustavsson]

Hi Wilhelm,

This picture shows the standard connection of two-wire microphones to a stereo plug.



If you are running long cables, I think you should use long balanced cables to the adapter and just short ones from the TRS connector to the microphones. There is no balanced connection between the TRS and the microphones. Cannot say anything about the phantom power adapter but I guess it is taking advantage of the differential inputs of the recorder.


Roger

[Schubida]

Hello Roger,

thank you very much for your answer! Could you please test this configuration? : Because  there is no possibility for a balanced connection between the TRS and the two microphones I only can use the "hot" solder pad ("drain") and the "ground" pad but not the  third pad of the mics, the "source". So one of the two shielded cables inside the microphone cable will be without any  function and I can let them unsoldered. Instead of it I have to solder the shields of both mic cable to the "ground pad" of the mics and to the ground of the TRS-cable. 

Best regards,

Wilhelm

[Roger Gustavsson]

Wilhelm, do you know how the cable connect to the capsule? Are yours looking like these? I think that the housing of the capsules will influence the sound.


Here are documents on Primo EM172 and EM173. EM173 seems to tolerate higher SPL.
http://www.twin-x.com/groupdiy/albums/userpics/EM172.pdf
http://www.twin-x.com/groupdiy/albums/userpics/EM173.pdf


Roger

[Schubida]

Hello Roger,

just finished my first self made mics based on the Primo EM 172 mics.  I can use them with my Sony HI-MD MZ-RH1 with and without the SP preamp from Soundprofessionals and with my Fostex FR"-LE via the Soundprofessionals y-adapter cable with phantom power converting option (SP-XLRM-MINI-2): Very clean recordings, very, very little noise (astonishing...) and - with both recorders - no hum!! I will use this mic stereo pair in a boundary rig (see "trackseventeen"), another pair in my selfmade binaural head with silicone ears and silicone earchannels (with Har-Bal 2.3 balancing option) for nature recordings.

The mic housing is made of aluminium tubes (inner diameter, 10 mm, 8 mm, 6 mm and 4mm). The cable is from "Cordial" (microflex cmk 209;   2 mm diameter, 1,80 m each) and the 3,5 minijack from "Hic-on", the "Neutrik" is a little bit to small for both cables. The solder contains 4% silver.

Thanks for your help! Great forum!!!

All the best,



Wilhelm

[Schubida]

Yes of course. But I´m a newbie in this forum and I don´t know how to upload a picture... Could you please help me?

Best regards,

Wilhelm

[furkin]

Did we ever see pictures ?

I'm interested in building my own too.

[moooose]

here is a picture of a pair of mics I built with Primo EM 172 caps. I built them around two disassembled neutrik rca connectors, in order to get a solid body - therefore they are not as small as possible.

[furkin]

Many thanks Moooose,

I'll reply via my own post ( http://taperssection.com/index.php?topic=147886.30    if anyone is interested)