From ja–(at)–n.com Mon May 13 09:46:48 CDT 1996
Article: 9661 of rec.audio.tubes
Path: geraldo.cc.utexas.edu!cs.utexas.edu!math.ohio-state.edu!howland.reston.ans.net!newsfeed.internetmci.com!in2.uu.net!en.com!usenet
From: “Jack A. Zucker”
Newsgroups: rec.music.makers.guitar,alt.guitar,alt.guitar.amps,rec.audio.tubes
Subject: Dr. Z Prescription Review
Date: Mon, 13 May 1996 06:51:32 -0400
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Dr. Z Rx Review
I recently borrowed a Dr. Z Prescription guitar amp. After a week of
playing it, I decided to write a review of it in order to share the
information with other network folks.
Description:
The amp has 3 12AX-7 preamp tubes, 4 EL-84 power tubes running in
class-A with no negative feedback, and a GZ-34 rectifier tube. As stock,
my evaluation unit had 2 NOS Phillips 12AX7s in the first gain stage and
phase inverter, and a Sovtek 12AX7 powering the 2nd and 3rd gain stages.
Rectification was handled by a Groove Tubes “Reactive” solid state
rectifier but may also be ordered with a GZ-34 rectifier tube. The power
stage is handled by 4 Tesla EL-84 tubes which put out about 45 watts.
The controls on the front of the unit from left to right consist of:
Bass, Mid, Treble, Volume, Expand Switch, high input, low input. The
expand switch bridges a capacitor across the first gain stage cathode
resistor for an extra thick tone. There is no reverb or effects loop.
Dr. Z was going for a design with an emphasis on tone and felt that
reverb or an effects loop would compromise the tone and integrity of the
signal path.
The controls on the back of the unit consist of 3 jacks for 4,8 or 16
ohms.
The head-cabinet is a very small, sexy enclosure measuring 9.5″ tall,
19.5″ wide and 9.5″ deep. I really like this design and it seems
equally at home on top of a 1×12 as well as a 4×12 cabinet. Very groovy.
Design:
The Dr. Z Prescription is a brand new design. Dr. Z does not make retro
or copy amps and this amp is no exception. While it certainly borrows
concepts from classic Western Electric circuit designs, you won
