Peavey JSX Amp Review

The 1980s were a turning point for guitar-based music. Not only have instrument and gear manufacturers began developing new and exciting stuff, but the guitar players themselves started pushing the limits and bringing it to a whole new level, ultimately giving birth to the famous shred movement.

One of the musicians who emerged from this era is Mr. Joe Satriani, who propelled the instrument forward and pretty much changed the game for everyone that came after him.

But being such a great artist, Satriani had great demands for the perfect tone over the years. We will be going more into one of the amplifiers he developed with Peavey, the famous JSX.

Of course, the amp has a few different versions – the 120-watt head, the 50-watt head, the 120-watt combo, and the small 5-watt version called Mini Colossal. Here we will be focusing on the big 120-watt head version.


So, obviously, the amp itself is quite powerful. And for such a big beast, it’s pretty obvious that there are going to be three channels.

They’re selected with the switch on the right side and are labeled as clean, crunch, and ultra. The amp also has two inputs, the low and high gain, just like some of the old vintage amps.

Since this is a tube amp, it has a pretty standard valve configuration. There are four 12AX7 tubes for the preamp section and four EL34s for the power amp.

Each of the channels has its own individual controls. All of them have separate volume and bass, middle, and treble knobs. The crunch and ultra, which are distorted channels, each have their additional gain knob, and there’s also a “fat” switch.

This control is a low-end frequency boost. And while it adds some bass to the mix, it won’t make you sound muddy or blurry, it just adds more thickness.

There’s one pretty useful feature for the crunch and ultra channels, and that’s the noise gate control. It’s controlled with one knob for both channels located next to the “fat” switches.

As for the shared controls, the master volume, presence, and resonance work with all three channels.

On the back panel of the amp, there is the standard send and return FX loop with additional level controls for both the input and output.

Located somewhere in the center of the back panel are two outputs for cabinets and a switch to pick between the 16, 8, and 4 ohms resistance. There is also a line output, which can come in handy, especially because it has its own separate level control.

It should also be noted that the footswitch is included that lets you switch between the channels and turns the effects on and off. Featuring three buttons, it’s pretty straightforward and simple to use.


Even if you really care about the looks – which is of great importance for some players – you probably won’t have any issues with the JSX.

The dark colored amp features all silver knobs and controls that go well together with the upper part of the front panel and the main cover that’s visally enhances by a “JSX” logo in the middle and the big “S” cutout around it.

The knobs and switches for all the individual channels are separated and encircled with white lines, so it’s pretty easy to follow through.

With this being a higher-end product, it’s needless to say that all the controls and the moving parts feel like they’re very well built.


Sonically-wise, this is an extremely versatile amp. The clean channel provides you with the crystal clear sound that can also work well with any distortion pedals you have in mind.

Setting up a sound is possible with almost any standard distortion pedal and all the controls are very responsive.

However, taking a listen to the crunch and ultra channels, you most likely won’t have any need for separate distortion pedals, unless youwant a mild overdrive like a Tube Screamer for some tone shaping and boosting.

The crunch channel gives a ton of possibilities, anything from quiet bright drives for bluesy rhythms and leads, over tasty ZZ Top old school kind of tones, all the way to some hard rocking and classic metal sounds.

With the use of the “fat” switch, you can get amazing results with thin sounding single-coil pickups on the crunch channel. Turning this feature on, it does kind of feel like you’ve swapped your pickup with a P90.

The ultra channel is a whole new level. You can achieve soaring rock leads, scooped black metal sounds, classic metal sounds, thick mid-range thrash metal tones, razor-sharp high-end Rammstein-esque stuff, or even fuzzy jazz lead vibes.

The options just seem endless. There are other amps with even more controls that didn’t give as nearly as many possibilities that JSX provides you with.

In addition to all this, you have both low gain and high gain inputs at your disposal, so this is another thing to play around with while you’re in your neverending quest for the perfect tone.


But let’s not make this just all about praise and share a few downsides. The first and obvious one, with 120 watts of power this is exclusively a live tube amp.

You need to turn it up to 6 or 7 to get a genuine sound out of it. And since there’s no power soak option, you can’t really play it in your bedroom or even a rehearsal room without blowing everyone’s head off.

If you’re not a touring live guitar player or just some enthusiast with a huge room in your house, Mini Colossal 5 watt version will come as a great option.

But if you’re a touring guitar player of pretty much any genre, you just can’t miss with Peavey JSX.

Video Demo with Joe

Young Coconut is a music geek and musician who has written and recorded over 20 albums and still going strong. His music ranges from rock, to electronic, experimental, and all points in between. He can be found recording at least 2 x per week at one of his favourite recording haunts.
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