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From: mikes@iuvax.cs.indiana.edu (Michael Squires)
Newsgroups: rec.audio.high-end
Subject: Re: Tube-amps
Message-ID: <8032@uwm.edu>
Date: 3 Dec 90 23:00:22 GMT
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In article <7965@uwm.edu> nvuxl!hsong@bellcore.bellcore.com (g hugh song) writes:
>
>What is **TECHNICAL** (proven) merit of hybrid/tube amplifiers over
>modern all-transistor amplifiers?  If you think transistors are better,
>give me the reason also.

Matt Morey, who designed a power amplifer for dB Systems back in the late
70's, used some impedance data taken from my speaker system at that time,
a double pair of KLH Nines.  These speakers at 20Khz were a half-ohm
load, mostly reactive.  The amount of current required was phenomenal;
a Dyna Stereo 400 connected to these speakers was quickly forced into
current limiting with obvious impact on the sound.  Tube amplifiers,
however, have much nicer overload characteristics into weird loads
like this particular ESL.  Matt eventually putt enough output devices
for a 200 wpc AB amp into their 40 wpc class A amp, which did sound
very good.

I'm not sure what kind of a load the ESL-63's are, but the Dayton-Wright
XG-10's used a complicated passive filter in front of the driver transformer
which also caused problems with some solid-state designs.

I personally don't see any reason why a new solid-state design can't sound
as good or better than a tube design, and lots of reasons why a solid-state
design after six months will sound better than a tube amp after six months.
On the other hand, on a budget, it is often easier to get a "good" amp
that is based on a tube output stage. This is the reason for the demand
for used Dyna Stereo 70's and Mark III's (I prefer the Eico HF-87/89, which
use a superior driver design).

-- 

Mike Squires (mikes@iuvax.cs.indiana.edu)     812 855 3974 (w) 812 333 6564 (h)
mikes@iuvax.cs.indiana.edu          546 N Park Ridge Rd., Bloomington, IN 47408
Under construction: mikes@sir-alan@cica.indiana.edu