Tandy RealisticPZM mircophones

[Rory McDonald]

I dont think Radio Shack (Tandy) still sells the PZM, as far as I know.  It
IS a crown PZM, marketed under the Tandy name, but it is unbalanced, and I
am not certain they use the same mic element in it.  When I was in recording
school (Golden West College, Westminster, CA) many MANY moons ago, our class
created the first commercial demo of the PZM for Crown, who bought the
rights from Dr. Wahrenbrock, the inventor of the PZM.  I have a number of
the original application notes (it was a newsletter) that Dr. W produced
before selling the PZM to Crown.  
Using the higher voltage battery gives about a 6db gain (and better S/N
therefore), if memory serves.  If you like I could look up the notes and let
you know more details.  I took a couple of the Radio Shack PZM's and made a
stereo plate mic for Grand Piano.  
It is two PZMs (the original plates removed) on a 2x2 foot plexiglas sheet,
with the elements on opposing sides of the plate, facing each other.
A PZM mic's element faces DOWN, towards it's plate.
Placed under the piano gives a pretty nice pickup- I augmented it by adding
CAD e100's under the lid. I have also used it for taping quartets in my film
scoring class.
The idea of a PZM is that ALL sound hitting the element is OFF AXIS, solving
phase problems considerably. They are not for everything, but they make a
nice ambient mic, and seem to work well for choral, string ensemble, and
piano. The app notes give all sorts of tricks and suggestions. 
Also, there is instructions on the web to make a Radio Shack PZM a balanced
mic, which will help for longer cable runs.
check out
http://www.hyperreal.org/music/machines/categories/do-it-yourself/schematics
/pzm.mic.mods
It describes several very useful mods, including replacing the crappy
transformer in their power supply. The original PZM had a separate Phantom
supply, not the cheap one inline on the mic cable that the Tandy uses.
whew!
-Rory Mc Donald


> -----Original Message-----
> From:	P.M. van Nugteren [SMTP:PMvanNugteren at gmx.net]
> Sent:	Wednesday, June 09, 1999 3:54 AM
> To:	Analogue Heaven
> Cc:	synth DIY
> Subject:	Tandy RealisticPZM mircophones
> 
> I'm looking for a pair of TANDY pressure zone microphones (PZM). They're
> very cheap about f100,- (Dutch guilders) ($50-60). There should be a
> TANDY shop in Antwerp, Belgium. The only other info that I have about
> them is that they tend to give a better S/N ratio when fed by one mono
> 12 V battery, They should give a sound comparable to Shure's PZMs (used
> with 12V batt)
> 
> So Europe listers, does anyone know that shop (phone number, adress) or
> knows where to get them?
> 
> Thanks,
> 
> Paul
> 
> PS: TANDY/realistic some connection with Radio shack?