Is the Gallien-Krueger 250ML the most versatile guitar amp ever produced?

I recently acquired a Gallien-Krueger 250ML guitar amplifier. Having owned it for a few weeks now, I’m starting to wonder if it could be the most versatile guitar amp put into production.

Gallien-Krueger (‘GK’) today is most known for its professional solid state bass amplifiers, such as the popular RB-series heads (one of which I own, the 700RB). Previously, however, GK produced a wider range of instrument amplifiers, including guitar amps. Carlos Santana used the GMT 226A at Woodstock in 1969, and in 1974 the GMT 200G was the first guitar amp with channel switching.

The 250ML first appeared in 1983, and quickly became a very popular amp, despite production ceasing in the mid-1990s. The difficulty in finding them in the used market (I got very lucky) is testament to their continued value, and amps still tend sell for $600–$800 when they appear.

But what is it?

It’s a 100-watt stereo combo guitar amplifier that’s the size of a lunchbox. It has two 6.5” Pyle speakers, each of which gets 50 watts, and can run two external 16Ω speaker cabinets in true stereo.

It weighs just 10 kgs (22 lbs), and measures 35 × 23 × 15 cm (13.75 × 9 × 6 inches). You can carry it in one hand and a guitar case in another, and be ready for practice, gigging or jamming.

It has two channels, each with two separate gain modes: Channel A is clean or crunch, and has a compressor; Channel B is overdrive and super-overdrive. While the level of gain achieved is preset (which may seem like a disadvantage, but the presets are apt for almost anything), this can be adjusted easily by internal trim pots.

Both channels have the same four-band active equaliser. Unlike many guitar amps, this means it can boost as well as cut frequencies. The controls are set at: 8 KHz, 2 KHz, 500 Hz and 120Hz. Each roughly translates to treble, high-mid, low-mid and bass. This is far more helpful than the ambiguous ‘treble’, ‘mid’, ‘bass’ and ‘presence’ controls on most amps.

But what’s the point of a stereo guitar amplifier if it’s a mono signal? Well, the 250ML has built-in genuinely stereo effects: echo (effectively reverb) and chorus. These are preset and very ’80s-sounding, but the chorus seems perfectly set to produce a subtle phaser-like effect when overdriven, and a shimmering vibrato when clean.

One of the many great things about the amp is that its tone doesn’t change when you increase the volume. The clean channel stays clean, the crunch stays crunchy, the overdrive is overdriven. It’s loud enough to practice at its lowest volume, and it can put the first two rows of the audience into a coma at about halfway. It sounds great at all volumes, and has more than enough power for most gigs.

There are a few other features that make it attractive too, including an effects loop, a stereo in/out, a balanced direct out, and a headphones socket to keep you from disturbing the neighbours. A footswitch can be used to switch between the channels and to toggle the effects on and off.

Yes, all that in something small enough to comfortably take on public transport.

The 250ML and other GK amps (and preamps) were widely used by major artists from the mid-‘80s to the mid-‘90s, including Iron Maiden on Somewhere in Time (you can see the 250ML sitting atop a stack of Marshall quad boxes in the ‘Wasted Years’ video) and Richie Sambora of Bon Jovi on Slippery When Wet (the 250ML makes an appearance in the band’s hotel room in the ‘Wanted Dead or Alive’ video, and you can hear it best in the guitar solo).

Perhaps the most famous user of GK amps is Alex Lifeson of Rush, who used the 250ML on Power Windows. Lifeson was a major endorser of Gallien-Krueger, as evidenced by this very dated magazine ad:

Of course, it’s not a tube amp. It doesn’t have that ‘tube tone’ many guitarists go nuts over. I’m not sure if that can be considered a compromise of the small size or not. Certainly I don’t find it lacking in tonal character, and I appreciate not having to let it warm up, leave it on standby, or wait for the inevitable blown tube.

I think what a lot of guitarists forget is how frequently solid state electronics get put in front of amps. Most guitarists will have a range of effects pedals, and it’s very rare to find any pedals that use tubes: they’re all transistor-based for the most part. A large amount of the sound is down to solid state pedals: overdrives, modulation pedals, delays, compression, equalisation and wah pedals appear in most pedal boards. Effectively the tube amp is just there to bring the signal up in many cases, and that could be achieved with a DI box run into the PA.

Instead, the 250ML provides you with a wide array of tools to shape the tone you want. It doesn’t produce a distinctive Marshall, Fender, Orange or Mesa Boogie tone. It produces your tone.

Is it the most versatile? I think, all things considered, it is. I prefer the GK 2000CPL guitar preamp which has a dual equaliser and better control over effects, gain and channel switching among other features. But the 2000CPL doesn’t have speakers, making it a bit more cumbersome.

The Gallien-Krueger 250ML is the most versatile amp precisely because it covers so many bases and packs so much power into one convenient package.