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Marshall JMD:1 100-Watt JMD102 Combo Amp Review

Marshall JMD:1 100-Watt JMD102 Combo Amp Review

Marshall''s foray into modeling brings the company''s famous amps together in one tube-powered combo

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Legend has it that Who bassist John Entwistle enlisted drum shop owner and teacher Jim Marshall to build a bass amp loud enough to be heard over Keith Moon's drumming. A short time later, Pete Townshend walked into Jim Marshall's shop asking him to build a guitar amp so he could be louder than Entwistle. And the rest is a rock and roll history. So, when the grimacing FedEx guy abandoned on my doorstep a 70+ pound box emblazoned with the iconic Marshall logo, I knew that whatever lay inside should be very loud indeed. And it was.

Turns out that what lay inside was a Marshall JMD102, the latest in hybrid amp technology from the most iconic amp builder in the history of loud. The JMD102 is a 2x12 100-watt combo from Marshall's new JMD:1 line that also includes a 100-watt full stack, 50-watt half stack, and 50-watt 1x12 combo.

Future and Past Come Together
Under 28" wide, 21" tall, and only 10" deep, this 2x12 100-watt all-in-one amp is only slightly larger than many 1x12" combos. Powered by four EL34 valves (I'm going with the British term since this is a British amp), it has plenty of raw analog muscle, which the Eminence AX75 speakers handle exceedingly well. While Marshall may have taken it on the chin when they went down market and started dabbling with solid-state circuits, they are still kings when it comes to focused output derived from valve power, and this amp shows off that legacy. What may give pause to some Marshall and valve power purists is the JMD:1's digital preamp and onboard effects. The digital preamp is Marshall's foray into amp modeling, and to make sure they got it right, they collaborated with Swedish DSP company Soft Tube, relying on their "Natural Harmonic Technology" for the 16 different digital preamps found in the JMD:1 series. Given the many classic Marshall tones throughout the company's history, adding simulations to any amp with the Marshall brand had to be daunting prospect, so they were wise to leave the simulations to experts in the field via Soft Tube while Marshall focused on what it does best—loud, proud, classic valve power and tone.

The sixteen preamps included in the JMD:1 series are, of course, based primarily on classic Marshall amps, including the 1959 Plexi, the holy grail of rock JCM800, and more recent models like the JVM series and Haze 40. A few Marshall's stompboxes and their MIDI-controlled rackmount digital preamp are also represented.

Controlling the Beast
The preamps are accessed from a single knob that breaks down the tonal palette into four categories: Clean, Crunch, Overdrive, and Lead. Marshall's standard set of controls for EQ and volume all respond differently based on the selected preset. This makes sense since, for example, the EQ knobs of a Marshall 1974 behave differently than the EQ controls on a JMP-1. Likewise for gain staging. So dialing up a preamp setting is like dialing up an amp, since all the relevant knobs will behave accordingly. The JMD:1 manual does an excellent job of explaining this along with the gain staging and signal path of each preamp setting.

The amp's front panel includes five LED push-button switches to store four amp presets. The fifth button (technically the first on the panel) puts the amp in manual mode (what you see is what you get). While only four amp presets and one manual setting are available from the front panel, there are 28 different amp presets available—seven banks containing four presets each. These are accessed using the included 6-way foot controller and are also available via MIDI. The foot controller is smartly designed and easy to use. LEDs tell you what preset you are on. The first four footswitches call up the presets of the current bank, and the two remaining footswitches allow you to increment/decrement through the seven available banks. Again, LEDs on the controller tell you what bank you are currently in. If for some reason you don't plan on using multiple banks of amp presets, you can change the foot controller to act as a universal controller for the amp. This mode, called Switch Mode, lets you assign each footswitch to a button on the amp's panel. So, for example, you can use three switches for different preamp tones such as clean, distortion, and lead, and use the remaining three to manage the JMD1's onboard effects and an external FX loop. Kudos to whoever thought of that!

The back panel of the JMD:1 has everything you'd expect from an amp, with some feature implementations worth noting. The FX Loop has a switch for +4/-10 dbv I/O, and has a Wet/ Dry knob. It can also be turned on and off via the amp's front panel of, if assigned, the foot controller. The emulated speaker line out uses a balanced XLR connection, and Headphone out, Line in, and Preamp out are also available via 1/4" jacks.

Okay, I'm dying to get to the tone, but, for the sake of due diligence, I need to mention that the amp has the standard Marshall controls, Gain, followed by EQ (Treble, Middle, Bass), followed by preamp volume, followed by a bunch of knobs and buttons for the effects—more on that later—followed by the standard Marshall Master Controls Presence and Master Volume. Got it? Let’s move on to the good stuff.

Click here for a larger image of the front panel

How It Sounds

Okay, let’s talk TONE, in capitals, for a reason. I am usually unlucky in the factory preset department, and historically have had to program my own patches to make use of whatever preset-enabled gear I am using. The JMD:1's factory presets are, however, quite useful. The most I had to do was turn the effects off since I was enthralled with the amp tone and not ready to play with mods and delays. The overdrive and distortion tones are Marshall all the way. Big, fat, excellent beef on the bottom and warm, bright highs on the top. The tone sounds much bigger than the physical size of the amp—not just loud, but big. No doubt having two 12" speakers helps here—so much so that I find it hard to go back to the 1 x 12s I am accustomed to lugging around with me. Saturation on the heavy distortion settings is both heavenly and wicked at the same time with very accessible feedback. In all the overdrive/distortion settings I played through, the amp just plain delivers. Sustain was excellent, and it responded naturally to the standard assortment of playing techniques. Every sound I wanted my guitar to make was transmitted accurately at any volume level I could get away with.

With that said, there is an inherent tightness in the sound. Is that a byproduct of digital simulation? Possibly. It wasn't necessarily bad, and the fact that I expected it may be a byproduct of being accustomed to tube amps that can be inherently unforgiving and raw when cranked, and tepid when turned down. Perhaps the relatively compact size and partially closed cabinet had something to do with it. At low, bedroom levels, the digital preamps offer as much distortion as you can take. And at bad neighbor volumes, the tightness was perhaps a bonus, as the tone remained highly defined and highly focused as opposed to just another loud overdriven valve amp. In addition, each distortion preamp retained its character at all volume levels.

Marshall's JCM800 has always been a favorite of mine, and more than any other Marshall amp, it exemplifies the Marshall overdrive sound. So it's no surprise that the JCM 800 model on this preamp was likewise my favorite. At high-gain settings especially, it is a very accurate representation of that classic amp. And the JCM2000 Dual Super Lead model accurately recreated classic tones from Gary Moore and Robin Trower with just a few tweaks to gain and EQ. Another accurate repro was the JVM410H preamp model, which took little effort to coax out some heavy metal tones a la Slash.

I could go on about the tone of the overdrive and distortion settings, but the amp has clean tones as well. Prattling on about clean tones on a Marshall feels a bit like talking about reverse gear on a Porsche, but they’re there for a reason. The pure clean tones had a definite Class A/B vibe to them, and some of the clean presets sounded a tad compressed. Musical but somewhat neutral, with super clean settings, the tone was just sort of there. Ah, but dial in a bit of crunch by either changing preamp presets (I chose the Dual Super Lead 100) or bringing up the preamp gain (stick with the DSL100), and a much needed dose of Class A character enters the picture, like Tom Joad in a John Ford film. No longer overly pristine and polite, the amp sounded man-made again—its anger in check, its soulful lament in heart wrenching bloom. Americana tones from a British bastard with a high brow Swedish education. Frankly, it's the first time I enjoyed playing a Marshall clean longer than five minutes (though I’ve never owned a Plexi). It also reminds me that at high gain settings, amps with digital preamp stages do not clean up as nicely via your guitar's volume knob compared to their all analog counterparts. Luckily there are enough clean tone models to switch over to.

The Effect of FX
Okay, so what are all those flashing red LEDs doing on a Marshall amp anyway? Face it, effects like modulation and delay are now standard fare on amps. Their practicality can be debated endlessly, and while no one buys a guitar amp because they like the delay, hey, they're here, we may as well use them. The usefulness of onboard effects often comes down to how easy it is to turn them off, and the JMD:1's well-designed footswitch succeeds in this regard.

The JMD:1's effects are based on Marshall stompboxes and include Delay, Modulation, and Reverb. The Reverb is what you'd expect on a modern amp—one knob, no springs. Of the four delays to choose from—Hi-Fi (pure digital delay), Analog, Tape, and Multi—the Analog and Hi-Fi were the best of the bunch. The Multi is a two-tap delay line with analog-style decay—I find digital delay repeats on multi-taps a la The Edge far more useful. The delay controls consist of a Delay Level knob, and an on/off switch that can be used for tap tempo, and can be assigned to a footswitch when the foot controller is in Switch Mode. Delay types, like the modulation types, are selected using the Delay or Mod Adjust knob respectively.

The four mod effects are Chorus, Phaser, Flanger, and Tremolo. Modulation controls consist of a Mod Depth knob and an on/off switch that can also be assigned to a footswitch. The limited access to effects parameters means you're at the mercy of the factory's tastes. The Chorus is totally usable, though I would go with a stompbox over the JMD:1's Phaser and Flanger. The Tremolo's speed has limited adjustment via the Mod Adjust knob, which hamstrings its usefulness. Turning the Mod Adjust knob hard left engages the noise gate, the threshold of which is controlled by the Mod Depth knob. The attack and release settings for the JMD:1's gate are hard-wired at the factory and very well done. So much so that I found myself using the gate over any mod effects—I have loads of pedals strewn across the floor anyway. This amp has me convinced that any amp offering heavy distortion should include a proper gate—the two go hand in hand.

The Verdict
With 16 different digital preamps to choose from, and the amp's primary controls adapting to the amps those preamps emulate, Marshall's JMD:1 series guarantees something for everybody. And likewise, you will probably find tones that don't satisfy your appetite. That's variety for you. The amplifier feels well made and thoughtfully engineered. Marshall may rattle a few rusty cages as they evolve into a modern amp company using cutting edge technology. Blame that on their legacy, I suppose. Fortunately, with the JMD:1 series, they have done a fine job blending modern with vintage for another great sounding amp with the iconic gold faceplate and white, cursive logo.
Buy if...
you need a loud versatile amp with great distortion and overdrive tones
Skip if...
you're a purist at heart and digital still doesn't do it for you, or you primarily use clean tones.

Street $1199 - Marshall -