Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site eosp1.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!allegra!princeton!eosp1!lincoln
From: lincoln@eosp1.UUCP (Dick Lincoln)
Newsgroups: net.audio
Subject: Re: 1/4" Phone jack/plug VS. XLR(3-Prong) connectors
Message-ID: <1175@eosp1.UUCP>
Date: Tue, 16-Oct-84 11:39:40 EDT
Article-I.D.: eosp1.1175
Posted: Tue Oct 16 11:39:40 1984
Date-Received: Wed, 17-Oct-84 06:35:46 EDT
References: <1647@garfield.UUCP> <2844@allegra.UUCP>
Distribution: net
Organization: Exxon Office Systems, Princeton, NJ
Lines: 21

> ....The practical drawback [to low-impedance microphones] is that the
> low-impedance signals, unless pre-amplified at their source, will have
> a much lower voltage coming into the mixer than a high-impedance
> signal of the same total power.  This means that to achieve low-noise
> operation you need an impedance matching transformer on every mixer
> input.  An impedance matching transformer is a VERY expensive piece of
> iron to build if you want combined wide frequency response, high
> efficiency, good shielding, and negligible distortion.  Thus many
> preamp manufacturers scrimp on the transformers, giving low-impedance
> microphones a reputation for slightly "grittier" sound among some
> audio purists......
  
> Van Kelly
> AT&T Bell Labs
> Murray Hill N.J.

Only one comment on this otherwise excellent response.  Expensive
transformers are not the only way to boost and convert the low signals
from low impedance, balanced sources.  Both my Carvin mixers have
operational amplifier integrated circuits on boards, four channels to a
board, that do this job very cheaply and very well.