Marshall Amp in a Box: Best JCM 800 Mimicking Pedal

QUICK SUMMARY: These are distortion pedals that sound most like a true Marshall tube amp, namely the JCM 800.

I'm writing this post as a summary of a thread on Ultimate-Guitar where the OP was asking about pedals that would most accurately mimic the tone of a Marshall JCM 800.

It got a lot of responses and a lot of different suggestions, which surprised me, because I'm always hesitant to assume that an effects pedal can come anywhere close to the distorting power of an amplifier, especially an amp like the JCM 800.

Here's the original post:

What I want to do here is go through all the suggestions that were made and post audio of the pedals to see how well they stack up to the tone of a real JCM 800. First, let's listen to what an actual Marshall JCM tube amp sounds like.

This is a good, straightforward demo with no talking. Skip to 1:05 to start getting into the distortion sounds. Gain goes to 10 at 2:35.

Remember, the original post was asking for the distorted sound, so we need to assume that the pedal we use is going to rest on top of a decent clean tone. That'll depend a lot on your own amp, especially whether it's tube or solid state. And while I don't necessarily recommend settling for a pedal instead of an nice amp, not everyone can afford a JCM 800.

I'll go through the pedals recommended in the post and add sound samples compared directly with the JCM 800 sounds.

The Golden Plexi by Tone City is designed to model a British tube amp tone and for such a low price point it comes ridiculously close, especially on the lower-gain sides of a JCM 800 comparison. I found it a little less convincing on the high gain settings, though still not entirely different than the JCM 800 demos. Admittedly, just about everyone who took the time to do a demo used a tube amp, so it's hard to say if the "Marshall-ness" came from the base clean tone of the tubes or the pedal itself.

I suspect it's a little bit of both. Either way, for 50 bucks, I'm impressed that it even reminds me of the JCM 800 tone.

• Amp Used in the Pedal Demo: Fender Deluxe (tube circuit)
• Sounds really close to a JCM 800 on lower gain settings
• Not quite heavy enough in a high gain shootout
• True Bypass

To be honest, the person who recommended this in the forum just said "ZVEX distortion" and I'm assuming this is the one they're referring to. The Box of Rock is designed to emulate a Marshall tone, though goes for more of a '60s than '80s vibe. It's not far off from the JCM 800, but definitely feels a little softer and less edgy.

You almost get a muddier, more fuzz-like sound than what I hear on the Marshall JCM 800s. That signature brightness that Marshall is known for definitely doesn't come forward in the ZVEX Box of Rock

It's expensive too.

You be the judge.

• Amp Used in the Pedal Demo: Fender Princeton Reverb (tube circuit)
• Very Marshall, but more of a '60s than an '80s tone
• Sounds "muddier" and not quite as bright as a Marshall JCM
• True Bypass

This pedal is directly inspired by the Marshall Plexi tone, right down to the control scheme, high treble and normal gain controls. These are meant to correspond to the two-channel system on most Marshall amplifiers.

While the High Treble control seems to help, I still think this pedal sounds muddier than what I'm used to hearing out of the JMC 800. If you listen to the samples below, the riffs Harry plays on the Stratocaster seem to get the closest. As of right now, I'd say the Golden Plexi is still my favorite, especially for the price.

• Amp Used in the Pedal Demo: Amp modeling software
• Guitars used: Strat, Tele, ES-335
• Made to emulate a Marshall Plexi
• High Treble and Normal controls get you closer to Marshall amp functionality

The OP mentions the Joyo Hot Plexi in passing, so I figured it would be at least worth comparing to the actual Marshall JCM 800 clips. Again, I haven't tried this pedal myself, but from what I'm listening to in the samples, it just doesn't sound very good.

I mean, it's distortion, but it doesn't really remind me of an honest Marshall amp like the others do. It even seems to do a good job of hiding what is otherwise a decent clean tube tone in the demo video (the guy who sounds like Jack Black).

• Amp used in demo: Dr. Z M12
• Guitars used: Fender Stratocaster
• Doesn't sound like much of anything
• You get what you pay for

In Brett Kingman's demo, the clean tone (which is only demo'd briefly) sounds fantastic. That said, it's likely the quality of tone you're hearing owes a big thanks to Brett's setup. On its own merit, the Crunch Box distortion is intended to function as a Plexi model, yet with a lot more versatility.

You get a four-band EQ and two switches for clip and mode, which allow you to move through a wider degree of intensity. 

I thought this pedal was at its best on the lower gain settings, almost like a blues driver. At the same time, heavier settings sound full and have plenty of sustain. I'd suspect it would be far less impressive on a non-tube amp model, but from what I can tell, the builders come dangerously close to a true Marshall Plexi tone, especially on the lower gain settings.

• Amp used in demo: Axe-FX II XL+ JTM45 + GB cab models
• Guitars used: Yamaha RS 820RCR (stock)
• Gets really close to a Marshall Plexi tone, especially on low gain settings
• Most versatile option, yet

This is another pedal demo by Brett, where he's now using some kind of a Laney amplifier to backup the pedal (I believe this demo was filmed much earlier then the Crunch Box demo). You can hear that the Laney amp doesn't lay quite as good of a clean sound as in his previous example, but the AMT M1 does a really decent job of powering past that. It sounds great overall while also capturing that brighter intensity of a Marshall JCM 800.

The AMT series was made to mimic popular amplifiers, so each pedal can function as its own preamp. 

In this regard, the clean base tone seems to matter a little bit less.

• Amp used in demo: Some kind of Laney combo
• Guitars used: Gibson Les Paul
• Modeled to be its own JCM 800-style preamp
• Can overcome a weak clean tone

I think it's really hard to compare an amp to a pedal, even if a pedal is billed as its own preamp. I've always preferred to get my distortion straight from an amplifier, as opposed to going through a pedal. Even the best distortion pedals can't compete with the gain you get from an actual tube circuit, especially when that circuit has been designed in Marshall or Mesa headquarters. 

In other words, the real thing is always going to be a lot better than the imitation. Preamp or not, there's something about the Marshall JCM and Plexi's tone that you can't replicate in a stompbox. 

Still, it's helpful to a lot of people if we can get close without spending $2600. 

The purpose of these pedals - and of the UG discussion - was to procure a distortion or "dirty" sound that could come close to what the JCM 800s produced. What it didn't address (at least not in depth) was what to do about a Marshall-esque clean tone or base EQ.

From what I noticed while watching these demos, the best way to help your plexi pedal win is to pair it with a tube amp that has a really nice, '80s style clean tone. That way you're not piling distortion on top of a bad base sound.

Use a decent tube amp (the Fender Deluxe series seemed like a popular option) and then take the time to dial in a good clean EQ.

From there, you can add your plexi pedal and then fine tune the entire thing.

If you have questions about these pedals you can refer to the comments section below or to the original Ultimate Guitar thread. Again, it's important to keep in mind that I did not review these pedals. I simply made a comparison between audio from an actual JCM 800 and the pedals that I saw suggested to imitate it, side-by-side.

The only one I thought really missed the mark was the Joyo Hot Plexi.

Don't buy that thing.

Everything else seemed like fair game and a decent, if not admirable, reflection of what an old Marshall JCM 800 is supposed to sound like.

If you have questions or thoughts about the pedals (or other recommendations) leave it in the comments section below.

Flickr Commons image via RockMixer