[BC] Mic impedance question...

[Milton Holladay]

Nahhh.....
Generally, the higher the input Z, the better, but usage has been all 
over the board.
E.g., early preamps used a step up xfmr into the grid of the tube (6J7, 
5879, 6267, etc.), usually with a resistor in series as a spurious 
oscillation suppressor, and only the interelectrode capacitance of the 
tube was any sort of termination.
Yet, there were passive mic mixers using 150 / 250 Ohm ladder or T 
attenuators and a combining network into a single preamp.
There are excellent input xfmrs by Jensen and others for use with 5534 
or 5532 chips as well as published circuits for use with these same 
chips with no xfmr  (at a cost of more noise ).
I can't imagine what you have in mind to use a pot for, as you need 
higher Z, not lower, IMHO.
Just connect it and see how it sounds; if not good, get a good preamp..
M

On 2/7/2012 00:18: VIRUS ALERT!, Glen Kippel wrote:
> I am putting together a basic recording setup to do my audiobooks and possibly some voiceover work and have a question about the load impedance presented to the mic.  Most of the mics I have been looking at show an impedance of 200 ohms (a couple are 75 and one is 50 ohms).  But the only mics that specify both their source impedance and a recommended load specify that the load impedance should be 1000 ohms or more.  The problem is, just about every mixer or USB adapter that I have spec'ed lists an input impedance of 600 ohms.
>
> Could this be detimental to the sound I am attempting to achieve?  I am kind of thinking of putting a dual, linear 1-K pot in a Bud box along with the appropriate XLR connectors so that I can set the load impedance to the recommended value.  Any comments or suggestions?
>
-- 
Milton R. Holladay Jr. / miltron at att.net
Columbia, S. C. / 803-331-8059
RF Measurements / Planning&  Installation / Emergency Service&  Parts