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Features: 7
Straightforward control panel with On/off switch, Standby switch,
Bass, Middle, Expand switch, Treble, 3 position Bright switch, Volume,
Lo and Hi inputs. Rear has 4, 8, and 16 Ohm jacks, as well as, a
'Boost' footswitch jack. Power section uses 4 EL-84s, preamp section
uses 3 12AX7's, and rectifier is a GZ34. Simple, no frills, to the
point layout! No master anything! 45 Watts of pure tube pleasure!
Sound Quality: 10
I primarily use humbucker style guitars (PRS McCarty and PRS Custom
22) with the Script and the tones from these guitar and amp combinations
are WONDERFUL. I play classic rock and blues and this amp is well
suited for both of these music styles. I play my Prescription head
through a 2x12 Z-Best Cabinet loaded with Weber P12Z's (Great cabinet).
I usually plug into the hi input with bass at 11 o'clock, mids at
3 o'clock, treble at 11 o'clock. I like to set the volume at around
2 o'clock and use my guitar volume knob to find the desired clean/lead
sound. Unbelievable dynamics! The Presription gives me incredible
string to string balance and definition. I characterize the Prescription
as having a nice tight low end, a strong warm midrange, and a non-icepicky
well defined high end. Nicely balanced warm clean tones! Ballsy
harmonically rich overdrive tones! OUTSTANDING! I might add that
this amp is a loud 45 Watts. Definately, plenty of power here!
Reliability: 10
Dr. Z' amps are built to last. His amps are extremely rugged and
are of the highest quality. His point-to-point construction is quite
impressive. I would gig without a backup. The amp has never broken
down. I have, however, had a power tube fail (loss of vacuum) on
me before. I replaced the bad power tube and the amp has performed
without a glitch. No problems with tubes since then. I've had amp
for 8 months.
Customer Support: 10
Dr. Z has top notch customer support. He stands behind his products
and he treats people well. He is personable, friendly, patient,
and organized. My Prescription was delivered when promised.
Overall Rating: 10
If my Prescription were stolen or lost, I would buy another one.
I really Love this amp. It's so much fun to play and it sounds wonderful.
Dr Z has really pushed the Class A EL-84 "tone envelope" with his
Prescription model. Amazing Amp!
Features: N/A
This is an earlier Z, with the black plastic panel, and rough black
covering. I will avoid this section for the most part, since Jack
Zucker and others did such a good job, just read the reviews below
for the full lowdown (including that monsterous one, the "shootout").
I'll just say that it's a 45 watt amp, powered by 4xEL84s, and has
four(4) knobs; Volume, Treble, Mid, and Bass. It also has an "expand"
switch and a three position "bright" switch.
Sound Quality: 10
I'll use this section to clarify my perceptions of the amp's tone
compared to the others. I'll try to be as helpful and descriptive
as possible. I was finally able to try this head out in a local
music store, as an individual was trying to sell it. I plugged it
into a reissue Marshall 4x12 cab (w/greenbacks) and went to town.
The first thing I noticed (like most people) was the midrange. That
stood out most with all of the controls flat, although with it down
some (w/single-coils) I could get a Beatle-ish kind of Vox sound.
One thing about it is that it never goes into the overly present
sparkle that is usually associated with Fender, but it is capable
of great high end, and even though it doesn't get "crispy", the
high end doesn't stab your ears either (like most recent Fenders,
especially those amps with the "blues" moniker). The frequencies
he gets with this amp are the ones that are usually "icepick-ey",
but it sounds as if Dr.Z has found a way of "blunting" them, so
to speak.
The late 60's Strat sounded okay through the head, but I could never
get them to sound "great", just "okay". I know, the amp isn't really
designed for single-coils, it's more for Humbucking designs. In
one review, it said that the "expand switch ratchets up the midrange
girth considerably". I don't know about that so much, but it did
seem to make the amp sound "thicker" with the Strat.
Plugging in the Les Paul was MUCH more rewarding. Immediately, the
amp fattened up and grinded accordingly, to some really gnarly early
ZZ Top kind of sounds, and, well, it also ventured into woman-tone
land, although it didn't seem to get any kind of "violin" tone going
- nope, couldn't get it to sound like Eric Johnson. Oh well. BUT,
it did sound KILLER, nonetheless. Contrary to what I thought going
in, it vot better sounds via the 'Paul with the "expand" switch
off and the "bright" switch on the brightest setting. It's Les Paul
classic rock crunch euphoria, you won't get that with a 70's Marshall
I guarantee you. "Like Butta".
NOW, the last axe was a G&L ASAT Classic. And lemme tell ya,
this is (IMHO) the best guitar you could plug into this amp. It
is possibly the best tone I have gotten out of an amp with it barely
turned up. I tried to make it sound thin, and it alluded to "thin"
but never got there, just slimmed down a bit. It got that Hendrix
sound I've never been able to get. It sounds like the later videos
of him live (not the ones where he sounds completely fuzzed out),
where his guitar sounds like a big, fat acoustic almost, and he
really gets down and starts hitting the strings real fast with his
picking hand. It was hard to ditch that sound, and I LOVED it! I
was going to rate it a "9" on sound, but this sound alone is worth
a "10".
Reliability: N/A
I'm sure they're very reliable.
Customer Support: N/A
I've never really dealt with the company, just gone to the website
a couple of two or three or ten times.
Overall Rating: N/A
Overall, I could definitely live with this amp, especially if I
could trade one of my guitars for the ASAT Classic to go with the
amp. I wouldn't go out of my way for it, as it only produces one
sound I'd really use, but it is absolutely THE BEST one useful sound
I have ever heard out of an amp, I'm still blown away that it could
get that sound, and this is an EL84 powered amp with a Vox-type
circuit design (maybe, although I wouldn't be surprised if there
were many hints of Marshall to be found there). I guess if you were
of the mentality to try and nail down a complex thing like tone
into just one catchy phrase, this one would be something like "Sounds
like Marshall and Vox had a baby." It's loud too, but overdriven
loud, not necessarily clean loud. I'm sure if I ran it through the
right cabinet it would sound great with the strat, it just sounds
a little boxed in with the Marshall cab and Strat. If I could get
the money now, I'm thinking of giving that guy an e-mail back and
try and work something out... well, maybe (it's a though, one of
many). If what I have said interests you, try and find one and try
it out. You'll like something about it at least.
Features: 10
Despite the fact that this amp does not have an effects loop or
master volume, I give it 10. The main feature of this amp is its
tone. If you like it, then you'll find that the controlls it has
is all you need. Besides regular Bass, Treble, Mid tone controls
(which by the way are very effective with minimal bleeding into
each others terretory) the amp has two toggle sitches on its front:
expand and bright. The first when activated beefs up the midrange
so your single-coils can sound nice and fat still retaining their
character. The second one affects 'higher' high frequencies and
is very effective in fine tuning different cabintes responce. I
found myself setting it to 'off' or '1' with open-back cabs and
'1' or '2' with closed-backs. It also has a footswitch jack for
'boost' on the back panel but I havn't tried it yet.
Sound Quality: 10
This amp sounds amaizing indeed. I totally agree with Jack Zucker's
review on this amp posted earlier. Just a couple things I want to
add... First is the incredible warmth and sustain this amps can
produce. It's totally unbelivable. Looks like Dr. Z worked very
hard to carve the right midrange responce. It's very warm but not
muddy at all. It reminds me the better Plexies I've heard but has
a certain character of it's own. Also it can be easily pushed into
feedback. And what a feedback! Not that sqeal that some of the modern
amps are producing (which sounds kinda like bad pickups) but very
musical with still plenty of that midrange. Second, is the amps
low-gain input. Inlike many other amps it is not just a wimpy version
of the high-gain input. It actually is tuned differently. To my
ears it has a little less sustain but much more brilliance in highs
still retaining that midrange warmth. Of course the sound does not
break up into distortion as like it does when plugged into high-gain
input. This is a perfect input for fingerstyle playing or just an
R&B-style rhythm work. A word of warning for those who are looking
for Boogie (of whatever else) style high gain preamp distortion
amps - this is not the one (and that is why it does not have a master
volume it simply would be a useless feature). What it has instead
is that wonderful output section distortion. Overall this amp has
a class-A el84 powered output section and, well, sounds like it...
But in addition it deliveres some of the goodies usually assotiated
with class A/B vintage British amps, i.e. it has a much tighter
bass response and overall improved transience and dynamics. In addition
it has its own unique character - it's hard to put it in words but
the amp feels very NATURAL. Many companies claim that their amps
become an extension of your instrument (or yourself). Many companies
claim their ams are so good they become 'an extension of your instrument'.
Well, Dr. Z is one of the few who in my opinion has full right to
say so.
Reliability: N/A
Didn't have it long enough to say... The amp seems to be very rugged
- the construction is simply beautifull. Output transformer is huge.
The tubes are well ventilated and the vents are protected by metal
grill. Treble control pot gets noisy when rolled all the way to
the left ('off'). I called Dr. Z and he offered to send me a new
pot and have someone in the city to replace it. I opted to wait
a couple years and have Dr. Z do it when I send the head for a 'check
up' (I never felt a need to roll highs off to that noisy position,
and by the way my Matchless SC-30 had same problem from day one
on one of the tone controls too).
Customer Support: 10
Customer support does not get any better.
Overall Rating: 10
I love this amp. And I think so do others who are lucky enough to
own one. I think Jack Zucker did a much better job in his review
than I ever could. The main reason I'm submitting my review is Feb97
Guitar Players Boutique amp shootout. Although I agree with almost
everything said in that review, two particular statements could
be very misleadng for those who never heard Z. First is saying that
Z didn't have quite the meanness and top-end complexity of Matchless
DC-30, second - that Z would make a good choise for those who already
own a big-name British amp and want different EL84 flavor. As it
so happens I now have both, Matchless SC30 and Prescription. They
both are excellent amps and to me comparing them is like comparing
a great-sounding Strat with a great-sounding ES-335. But since they
did it in one of the aspects (top-end complexity), let's continue...
First, I agree about top-end complexity. Now let's take a look at
the midrange. Both amps excel in that area, but the Z sounds a little
warmer (some probably would say 'less hi-fi') and has a better sustain
without loosing its focus when pushed hard. Lows - both have HUGE
lows if you dial it up but C30's lows get loose on higher levels
while Z's stay punchy and tight. Now they broke even... If your
thing is that Matchless C30 tone then only the Matchless will do,
but if you dig el84 class-A tone but want it to be a little more
'marshallish' then nothing would match the Prescription. Now, the
only thing I want to add to the second statement ('good second amp
choise') is just: beware it might take a place of your primary amp
very soon. At least it did it to me...
definition. more 'hi-fi' and gets somewhat
Features: 10
I have taken the liberty of posting here a review of the Prescription
written about a year ago by Jack A. Zucker and originally posted
in a guitar newsgroup. I personally own a Prescription combo and
absolutely love it. I considered writing my own review but this
one was so thorough and well written, I figured I could not do any
better. Obviously, I agree with everything in this post.
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 1x12 as well as a 4x12 cabinet.
Very groovy. 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't find its schematic in the Tube Amp Book. The
amp employs a fairly novel conjunctive filter circuit before the
output stage which seems to really juice the amp up and give it
a very original tone.
The amp is built almost entirely of parts designed by Dr. Z himself.
Dr. Z has his own special formulation (Sprague) capacitors which
are not available commercially. They are designed to react in a
similar way as the old "Black-Cat" capacitors which were used in
many classic early 60's amps. Transformers are manufactured to his
specifications as well. The output transformer in the prescription
is huge. It has 11 interleaves, paper bobbins, etc. Though the amp
puts out about 45 watts, the output transformer looks like something
you'd see in a 100 watt amp. (For those of you doubting the output
rating, I compared it to my 50 watt Plexi Marshall which is really
loud and the Z amp kept up with it pretty well.
Resistors are NOS Allen Bradley carbon composition. Pots are CTS,
jacks are SwitchCraft. Wire used throughout is 600V, solid core.
The components are hand wired on custom made glass boards using
turret posts. Turret posts make better electrical connections, are
more reliable, and less prone to cold solder joints than eyelet
boards. The tubes, while not designed by Dr. Z, are hand selected
and matched in order to make the amp as quiet as possible with the
best tone possible. Dr. Z is extremely committed to doing that and
I've seen him painstakingly going through phase inverter tubes and
measuring the voltage of each triode until he finds a tube which
is a match. (A 12AX-7 consists of 2 triodes in one glass bottle).
Sound Quality: 10
First of all, let me say that the amp sounds amazing. It's dripping
with tone. From the very first note, you can hear and feel it..
The amp's tonal range encompasses many facets. The first thing I
noticed was that the amp sounds radically different depending on
what range the volume control is set to. The volume control seems
to be calibrated into 3 distinct areas: Clean-Sheen, Bluesy/Stingy/Crunch,
and High-Gain
Clean-Sheen
Beautifully clean and chimey. The tone was bell-like and glassy
with a piano-like clarity on the low notes. Note separation was
very good. Playing complex jazz chords with 1/2 step voicings, I
was able to clearly discern each individual voice of the chord.
Playing riffs across the guitar from low strings to high strings
demonstrates the evenness of the amps tone across a wide frequency
range. I was able to get a really full bodied jazz tone as well
as a really sweet maple neck Strat tone.
Bluesy/Stingy/Crunch
Using a Strat and with the volume about 1/3 the way up, I could
get a really great Stevie Ray Vaughan tone. At this volume level,
overdrive and compression are controlled by the guitar's volume
control. With the guitar's volume partially down, I was able to
get that really sweet, clean, wispy Strat tone that I've been looking
for forever, and with the guitar's volume pegged, the amp is just
starting to distort. If you've heard SRV's Texas Flood CD, you know
the tone I'm talking about. Switching to a 335 brought out another
completely different personality in the amp. With the guitar's volume
down and gradually increasing the amp's volume, the sound went from
slight compression, to crunch, to a really bluesy/stingy/cutting
tone. Turning the guitar full up yielded a very rich, bluesy, distorted
tone. Not the least bit buzzy or unnatural. Playing on the treble
pickup yielded a really rich, smooth overdrive, not unlike Eric
Clapton's live Crossroads tone.
High-Gain
Turning the amp up past halfway increased the gain and harmonics
considerably. Here, the amp started to take on the character of
the Eric Johnson violin tone. With my buddies Les Paul and Pearly
Gates pickups, the amp yielded a very fine early ZZ-Top tone. I
was able to get harmonic feedback, squeals and squawks on just about
every note and the incredible touch sensitivity was astounding.
The only other time I've had a ride on such a wild beast was playing
a fully cranked 100 watt Plexi-Marshall through two 4x12 cabinets!
Tone Controls
The tone controls on this amp are wonderful. They are specially
tuned to enhance the bass, mid, and treble bands that most effect
the guitar's tone. When the controls are at the 12 O'clock position,
the amp sounds very natural. The effect is not unlike having a detent
position and being able to add or subtract from the zero point.
Sweeping the tone controls up or down yielded clearly audible, yet
musical results. This was very pleasing to me since so many amps
today suffer from tone controls which either do nothing, or are
so severe that the majority of their range is unusable. Again, this
is not the case with the Prescription. In fact, I could not find
a combination of tone settings that was not extremely musical.
And More...
At this point, you're probably wondering if this amp suffers from
multiple personality disorders. I'm here to tell you that Sybil
has nothing on this amp. Read on...
A few days ago, I picked up a blues CD which had some really nice
tweed guitar sounds on it. It was a recent recording but done in
the style of the old Howling Wolf or Muddy Waters sessions. I really
loved the guitar sounds and it inspired me to try to get those sounds
out of the Prescription just for kicks. I decided to change the
preamp and rectifier tubes to see if I could get more of a brown/tweed
sound out of it.
I replaced the first preamp tube in the Prescription with a GE 12AY-7.
(This is the tube the '59 bassman had in this position). I replaced
the phase inverter tube with a GE 5751 which is a lower gain than
a 12AX-7 but higher than an 12AT-7. The last thing I did was to
substitute a Sovtek 5U4 rectifier tube. Because of it's higher internal
resistance, the Sovtek tube lowers the plate voltages on the EL-84s
as well as gives the amp more sag. Additionally, having seen many
tweed amp circuits, I decided to leave the "enhance" switch in the
off position since many tweed amps employed no bypass cap for the
cathode of the first preamp tube.
Voila ! Instant tweed. I could not believe the difference. With
my Strat, the amp sounded incredibly like the tones I heard on the
blues CD. With the amp on 4 and the volume turned down on the guitar,
the tone was full bodied and clear with lots of sustain, and with
the guitar full up, the amp just ripped. It sounded very woody and
reminded me of many tweed amps I had played and heard on records.
I plugged my 335 in played a few notes and once again my jaw dropped.
With these tubes and the amp up about 1/2 way, the amp sounded almost
exactly like Eric Clapton's tone on the John Mayall Bluesbreaker
recordings. It was fatter, darker, less distorted, and less harmonically
rich, but it had the touch, tone, and feel of the record. Twisting
the treble control, I found that I could make the amp transition
from '59 Bassman to '64 JTM-45. I've played through several original
'59 bassman's as well as original JTM-45s and I would have to say
that this amp holds its own with any of them. I suggested to Dr.
Z that he make available a "Tweed Upgrade Kit" consisting of the
12AY-7, 5751, and 5U4 rectifier tube. This seems like a simple way
to add a whole plethora of sounds to the amps palette.
Reliability: 10
The actual mechanical structure is simply wonderful. The chassis
is solid aluminum with a special plating. This material increases
the conductivity to that of solid copper, yet retains the strength
of aluminum. This is an important factor in reducing hum and maximizing
tone. All wire runs are as short as possible and bent to right angles.
Dr. Z is very meticulous about wire routing and I noticed that extreme
care was taken to keep AC voltage wires away from signal grid wires.
There are no loose wires or silicone goo holding parts together.
Whenever possible, wires are twisted together and/or wire wrapped
with cable ties. No parts are hanging in the air either. Soldering
is very carefully done as no wires showed signs of insulation burning,
and all solder joints looked very solid, with just the right amount
of solder applied. This amp is built for the long haul.
Customer Support: 10
Overall Rating: 10
In closing, I would have to say that this amp produces the widest
array of tones I've ever experienced from a single amp. It's possible
to go from 50's tweed, to 60's plexi, to 90's violin-tone. It's
well built, well designed and well thought out. The designer Dr.
Z, personally builds and inspects every amp. He does not employ
students to build his amps and he does not have a factory. He works
out of his basement and has resisted attempts to be bought by larger
companies. He's very committed to making hand-built amplifiers for
guitar players who are fed up with paying exorbitant prices for
vintage or retro gear. His philosophy seems to be very simple: Hand-build
a top quality, original product, designed to last a lifetime which
will become an extension of the player's personality and sound.
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Prescription
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