Marshall JMP-1 review
Jeff Beck
I just bought a Marshall JMP-1 MIDI preamp, and I thought I might post a
review for all of you folks on the net, so here goes:
The Marshall JMP-1 preamp is a single-space rackmount preamp that supposedly
contains the same preamp electronics found in the Marshall 9000 series
amplifiers. It also contains some digital control circuitry, and of course,
a MIDI interface. The JMP-1 is mono input and stereo output. It contains
an effects loop that is mono out to the effects, and stereo return. The
stereo returns define the stereo output of the preamp itself. The preamp
also has stereo speaker emulator outputs that can be connected directly to
a mixing board for recording or for live performance, although it is probably
meant more for recording.
I have only played the preamp through a Roland JC-120, going from the preamp
output directly to the JC-120 power amp input, so I cannot comment on how
this preamp would sound if it was driving a tube power amp and a 4x12 cabinet.
However, even with the Roland amp, I think this unit sounds pretty good.
The sound controls are as follows:
There are four basic sounds to choose from:
1. OD1 - overdrive one - early "classic" Marshall sounds - bluesy
2. OD2 - overdrive two - newer sounds - a more heavily distorted sound
3. CLN1 - clean one - a clean channel - warm and dark
4. CLN2 - clean two - a brighter, jangly sound
I may have reversed CLN1 and CLN2, but the descriptions are correct.
The preamp also has controls for bass, midrange, treble, and presence.
Each of these controls has a range of -6 to +6. There are also two volume
controls, pregain, and postgain, (each range fromn 0 to 20) along with a
rotary knob on the front that controls the output volume to the power amp.
Note that this rotary knob DOES NOT control the volume output of the speaker
emulator. I personally think this is a nice feature for live performance
because I can adjust my stage volume without affecting the signal level
going to the mixing board. There is another feature called "bass shift"
which is supposed to give the sound a more "balsy" sound to it, which I
think it does well. Basically, all it does is increase the crossover
frequency between the bass and midrange tone controls when turned on.
There is no frequency adjustment, it is either on or off.
As far as the sound, it definitely sounds like a Marshall. The controls
provide a pretty good range of adjustments, so you can get most every
sound that you would want. I am extremely impressed with the speaker
emulator output. I ran the speaker emulator output into a Mackie mixer,
into a Peavey CS400 into a pair of EV speakers, each with a 15" and horn.
I thought the sound was almost as good as that coming out of the Roland amp.
One thing to note is that turning on the bass shift feature improves the
sound through the PA, but is not needed for a guitar amp. My advice would
be to adjust the sound through the PA first, and then compensate for any
quirks in the stage sound by adjusting the stage guitar amplifier.
As far as controllability, it is pretty good. It does have about the same
amount of control that a non-rackmount Marshall amplifier would have.
I replaced a Chandler Tube Driver with this Marshall unit, and I believe
that I miss the bias adjustment found on the Chandler. (BTW, if anyone is
interested in buying the Chandler, send me email. It basically is a
Marshall preamp, but it is not MIDI, and you only get one setting at a time).
I am somewhat of a MIDI novice, so I can't comment authoritatively on the
MIDI implementation, but here's what I found. The MIDI section has
built-in MIDI mapping, both input and output. So, I can send it a command
to change to patch X, it can map that to patch internal Y, and can map the
output patch command to still another patch Z. I think this will be useful,
because when using the unit with a footpedal that is sending out patch '1',
the JMP-1 changes to patch '0'. It is always behind by one patch, while my
Korg A3 in the effects loop is on the correct patch.
Summary:
I think this unit was well worth the $750.00 (including tax and (2) cables)
that I paid for it. A different store in town is selling them for around
$925.00, and they didn't seem to think they would come down, BUT that was
only their estimated price. I would have liked to see a control for the bias
of the tubes, rather than only having OD1 and OD2, but you don't get those
controls on a Marshall amp anyway. One really good thing is that there
is absolutely NO delay between patch changes, unlike my Korg A3. Fortunately,
the patch changes in the Korg shouldn't cause a problem, because the Korg
is in the JMP-1's effects loop, not in series with it. Programmability
is extremely simple. All you have to do is push the button of the parameter
you want to edit, and then turn the adjustment knob. Then just hit the
"store" button twice. If you want to store to another patch, just hit the
"store" button once, twirl the knob to the right patch, and then hit the
"store" button again. Oh, BTW, it does have patch protection capabilities.
Considering most places are asking over $1000.00 for the Mesa Boogie Triaxis
preamp, I thought the Marshall was a good deal. If you are looking for a
Marshall sound, but like the idea of having a MIDI controllable preamp, like
I really do, this might be the unit for you.
Happy jammin' all!
--
Jason Bold - Madison, WI: +===+ o +===+ Yeah, but two
bold%astroa...@spool.cs.wisc.edu | | /|\ | | amps can go
|~~~| Co-"= |~~~| up to 22.
"With this amazing new "knife"... |___| / \ |___| So there!
phs...@vaxc.cc.monash.edu.au
> Hi all,
>
> I just bought a Marshall JMP-1 MIDI preamp, and I thought I might post a
> review for all of you folks on the net, so here goes:
>
From your description, the JMP-1 sounds very similar in operation and
functions to the ADA MP-1 midi pre-amp, apart from the cabinet emulator.
It would be interesting to directly compare the distortion sounds from
the two. I have an ADA, and I love the clean sound from it, but I have to
admit I'm getting a bit bored with the distortion sound, which can't be
varied a huge amount.
Greg
****************************************************************
*** Greg Anders, Physics Department, Monash University - Australia.***
****************************************************************
Disclaimer: The thoughts expressed above do not represent the opinions
of anyone, least of all me.
Bill Leff
In article <1992Oct12....@astroatc.uucp> bo...@astroatc.uucp (Jeff Beck) writes:
>Hi all,
>
>I just bought a Marshall JMP-1 MIDI preamp, and I thought I might post a
>review for all of you folks on the net, so here goes:
For the record, the latest issue of Guitar Player (the issue featuring
slide guitar) did a review of the JMP-1 vs the Boogie Tri-Axis.
In a nutshell, they loved the JMP-1 for it's great sound and ease-
of-use. I think the only thing they didn't about it was it was
the design makes it difficult to change tubes quickly. As for
the Tri-Axis, they pretty much slammed it for what they referred
to as "harsh and thin" tones, but found it more versatile
then the JMP-1 (I think they were trying to find something nice
to say about it). They even described one of the lead voices
as having a "paper tearing sound"!
-leff
--
-------------------------
The number one reason why we're here (from David Letterman's Top 10):
"To polka, baby, polka"
Robyn Landers
Thanks Jason for posting a review of this product!
Were you able to compare it to the Boogie Triaxis, or did
the price tag on that keep you away entirely?
I don't like to be negative about a small point in an otherwise
good posting, but I will take issue with this statement:
> (BTW, if anyone is interested in buying the Chandler, send me email.
> It basically is a Marshall preamp, but it is not MIDI, and you only
> get one setting at a time).
Calling the Chandler Tube Driver basically a Marshall preamp is
rather generous. A typical Marshall preamp consists of three
12AX7 tubes (including the output driver stage), whereas the
Chandler has just one 12AX7 and an op-amp chip generating its sound.
However, the Chandler does sound good (I have one too) and I recommend
it to those looking for a good distortion device. Buy Jason's
and you'll both be happy.
-----
Robyn
rbla...@math.uwaterloo.ca
"I'm just doing my rock'n'roll duty." -- Dubois
Pasi Korhonen
: For the record, the latest issue of Guitar Player (the issue featuring
: slide guitar) did a review of the JMP-1 vs the Boogie Tri-Axis.
What kind of other equipment they used for testing ? Guitar, power amp
etc. ??? I have tested TriAxis briefly, and had quite contrary
experience. I didn't get too harsh sounds out of it. I had it
rigged to Boogie tube power amp and Boogie cabs, though.
Pasi
--
p a s i k o r h o n e n p k o r @ p h o e n i x . o u l u . f i
saaristonkatu 3 A 6 90100 oulu finland,europe tel:358-81-377 81
be...@athena.llnl.gov
>: For the record, the latest issue of Guitar Player (the issue featuring
>: slide guitar) did a review of the JMP-1 vs the Boogie Tri-Axis.
pkor@phoenix (Pasi Korhonen) writes:
> What kind of other equipment they used for testing ? Guitar, power amp
> etc. ??? I have tested TriAxis briefly, and had quite contrary
> experience. I didn't get too harsh sounds out of it. I had it
> rigged to Boogie tube power amp and Boogie cabs, though.
well, we're in luck, as i just happen to have the pertinent issue at hand. ;-)
"We tested both preamps side-by-side, using Boogie's all-tube
Simul-Class 2.90 stereo guitar power amp and leather-clad 4x12
cabinet, loaded with 30-watt Celestions. The 2.90 uses eight 6L6s to
deliver 90 watts per channel and takes up only two rack spaces. Our
intent in running both preamps through the same amp and speaker system
was to provide a consistent environment for our tests."
while they don't give an exact list of guitars used, they do give some
hints like: "For what it's worth, we noticed that P-90 pickups sounded
better that Strat signle-coils or our collection of humbuckers."
[note: this was in reference to the lead 2 red setting on the boogie
tri-axis.]
and in fairness to boogie, the exact comments on the tri-axis were
"Compared to the '64 Fender SUper Reverb we used as a clean reference,
the TriAxis has a pronounced midrange. You might call this Boogie's
sonic fingerprint."
and
"Overall, however, we found the TriAxis' distortion somewhat
processed-sounding, though this is certainly a matter of taste and
playing style. Also the bass response seems a little loose and
unfocussed. (Boogie says they tailor the bass response to work better
with a band.)"
and lest people be led into believing that nothing bad was noted about
the marshall...
"Compared to the TriAxis, the JMP-1 hisses like a desert sandstorm at
extreme gain levels. Excepting the Boogie, however, this hiss level
is no worse than other high-gain preamps or modded heads we've tried."
if there's demand for it, i could be persuaded to type the entire
review in...
from my own experience (and i've only spent a few hours with each
preamp, but don't own either... yet... ;-) the TriAxis and JMP-1
preamps are faithful extensions of previous products available from
their respective companies. The TriAxis is very remniscent of a
Boogie Quad-preamp with Mark II and Mark IV preamp sections added.
the JMP-1 is like a 9001 preamp with JTM-45 and a JCM 900 hi-gain
preamp sections thrown in. i happen to like both the boogie sounds
and the marshall sounds (i have both a quad preamp and a 9001), but i
haven't wanted to upgrade bad enough to justify the money. i think
the bottom line difference here is defined by the type of music you
want to play...
cheers,
bert
==============================================================================
bert still, numerical math group, LLNL | _ _ Katherine
(510) 423-7875, sti...@llnl.gov | / `-' ) ,,, the Great
postdoc/mathematician/sometimes musician | | IU U||||||||[:::] Riding
what? my rack doesn't fit in the truck?? | \_.-.( ''' School
==============================================================================
--
bert still, numerical math group, LLNL | _ _ Katherine
(510) 423-7875, sti...@llnl.gov | / `-' ) ,,, the Great
postdoc/mathematician/sometimes musician | | IU U||||||||[:::] Riding
what? my rack doesn't fit in the truck? | \_.-.( ''' School
Greg House
|>"Compared to the TriAxis, the JMP-1 hisses like a desert sandstorm at
|>extreme gain levels. Excepting the Boogie, however, this hiss level
|>is no worse than other high-gain preamps or modded heads we've tried."
Ah, so it *is* just like an ADA Mp-1...
Greg