From: bbaker@novell.com (Brad Baker)
Subject: Re: Eminent Technology Model 8s
Originator: tjk@csd4.csd.uwm.edu
Organization: Novell Inc., San Jose, Califonia
Date: Tue, 18 Aug 1992 15:39:00 GMT
  (5.65c/IDA-1.4.4 for rec-audio-high-end@uunet.uu.net); Mon, 17 Aug 1992 10: 36:36 -0700

In article <1992Aug14.152825.17274@tc.cornell.edu> eacj@theory.TC.Cornell.EDU (Julian Vrieslander) writes:
>In article <1992Aug13.212605.3708@novell.com> bbaker@novell.com (Brad Baker) writes:
>The two generalizations above indicate that Brad is a bit confused about
>component matching issues.  There are two component interfaces that he
>is concerned with: the preamp/power amp interface, and the power amp/speaker
>interface.
>
>Let's consider the preamp/power amp interface first.  Some passive
>preamps do not match well with some power amps.  Usually, this is because
>the power amp has an input impedence that is too low for the preamp, or
>because the preamp cannot provide enough voltage swing to drive the
             ^^^^^^
I think you mean CD player here, right?  Passive preamps do not provide
voltage swings.  At least the one that I have :> 
I don't want to get into that "what is a passive preamp" thing.
I consider passive to mean NO POWER CORD. Simple.


>power amp to the desired output levels.  There can also be problems if
>a passive preamp is used to drive long (or highly capacitive) interconnect
>cables to the power amp.  I (or others on the net) can elaborate on these
>issues, if more information is needed.
>
>At the power amp/speaker interface, there is no "passive" vs. "active"
>issue, since a power amp *must* be an active, power supplying device.  There
>is no such thing as a passive power amp, since something must supply the
>electrical power that the speaker converts into acoustical power.  There are
>mismatches that can occur between speakers and power amps, but that's
>another story.
>
>A badly matched preamp/power amp combination may cause the signal
>reaching the speaker to be distorted, limited in level, or altered in
>frequency response.  Depending on the speakers that you use, and your
>own perceptions, these effects may be (a) inaudible, (b) detrimental,
>or (c) pleasant.  But it makes no sense to say that a passive preamp
>(or active preamp) works better or worse with a given speaker, because
>the preamp does not directly interface with the speaker.
>

You are correct, but I disagree with your reasoning. 
It does not make sense, because the rest of the
components come into play.  Whether or not they interface with
the speaker is unimportant since everyone knows that changes
in components in the audio chain "upstream" of the amps can 
greatly affect the sound.

The point that I was trying to make was that had I listened to the 
ET's through an active preamp with a "hotter" signal (higher voltage
swing?), that they would have probably sounded quite different; 
probably more dynamic with better bass.  You could equally say that
had I used a more efficient power amp, or a CD player with a "hotter"
signal, that the same could be true.  However, I believe that the
VTL's work very well with passive units (does that mean low input 
impedance?), and that the EAD has a high output voltage when compared
to most CD players.

Brad


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