Goodsell 33 Custom Mark IV Guitar Amp — Review

June 20th, 2014

By Chris Gill | Photo by Massimo Gammacurta

The popular saying “you can’t judge a book by its cover” could be rewritten for guitarists as “you can’t judge an amp by its tube complement.” The Goodsell 33 Custom Mark IV, with its quartet of EL84 tubes, is a perfect example of this. Chances are most readers had an instant word association response of “AC30” when they read “EL84 quartet,” but the Goodsell 33 Custom Mark IV is a much different beast than that famous Vox combo.

Actually, the 33 Custom Mark IV has more in common with the popular 5F6-A tweed Fender Bassman circuit, but with its EL84 power-tube quartet that provides 33 watts of output, single 12-inch speaker, and additional features that include a gain control, reverb, and tremolo, it’s not a Bassman knockoff either.

The 33 Custom Mark IV’s circuit utilizes cathode biasing, a GZ34 tube rectifier, a cathode follower¬-powered tone stack, and a long-tailed pair phase inverter to provide a compelling combination of outstanding clean headroom and dynamic tweed overdrive crunch with just the right amount of sag. Its control panel offers just the basics-gain, volume, treble, mid, and bass (no presence control as found on a Bassman), along with a level control for the spring reverb and speed and depth controls for the bias-vary tremolo circuit. The reverb and tremolo circuits remain out of the signal path unless engaged, avoiding the “tone suck” effects often encountered with classic amp circuits. The model also includes a half-power switch that cuts the output to 17 watts.

In essence, the 33 Custom Mark IV is the 33-watt big brother to Goodsell’s popular Super 17 Mark IV. The biggest difference is its louder volume output and greater clean headroom, which makes it a better choice for use onstage. The clean tones are world class, with a three-dimensional treble sparkle, tight percussive bass, and full-bodied midrange that’s elusive in most 1×12 combos. The gain control is a nice addition for modern players, allowing guitarists to dial in rich, harmonically complex distortion at any volume level. The amp’s sweet spot lies in the one-to-three-o’clock volume control settings where players can seamlessly switch from crystalline clean to overdrive raunch just by altering playing dynamics or guitar volume control settings.

The amp’s reverb and tremolo effects are also as good as it gets for a combo amp. The bias-vary tremolo circuit is very versatile, providing everything from a subtle rolling-wave effect to dramatic, helicopter-like chops just by adjusting the depth control. The reverb is smooth and sweet, with long, dreamy tails instead of the boingy, surf music chirp of cheap spring-reverb units.

Goodsell Amplifiers,

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  3. Posted by Stephen Anderson on June 28th, 2014, 14:17 [Reply]

    I own three Goodsell and recommend them to everyone… In fact I sold all of my vintage Fender amps as Goodsell eclipses them all!

  4. Posted by Dave on July 11th, 2014, 10:20 [Reply]

    I own this amp and Richard just built a Custom Valpreux with 40w/21w toggle!! They are ‘Jekyll and Hyde’!!! The tones are intoxicating!!!!


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