copying the important parts of the article in a verbatim manner: "Both Thompson and Root said that when they recorded the band’s first album, their choices in gear were very limited because they couldn’t afford anything other than what they already had. Thompson used a Rocktron Piranha pre-amplifier powered by a Mesa Boogie 295 power amp."more
The high gain is where this preamp shines. This preamp is tonally based on the Mesa Rectifier, and it really shows. It's thick, chewy, and crunchy just like a Rev-G Dual Rectifier, and you SERIOUSLY cannot beat the tone for the price, considering you can find these things for under $400. The EQ section doesn't work exactly like a Recto's EQ section (mesa is known for their crazy EQ sections), but the core tone IS there, and the EQ still gives you plenty of tonal tweaking, ESPECIALLY with the parametric midrange. Scoop your mids wherever you want, crank your mids wherever you want. The range is quite wide as well. 250hz - 7khz. On top of that, the EQ section is digitally programmable. You can dial in a tone, save it, and scroll through them as if you were using a modeler. It's also MIDI-capable, so you can recall your presets via MIDI.
I really debated on making this a 5-star review, but this preamp isn't THE most versatile. The clean and crunch tones are lacking, and I'm not too fond of the built-in Hush. The Hush is in the loop, so it isn't the best if you want to quiet down a noisy pedalboard. You'd still need a noise gate in front of your board.
With that said, the tone of this amp is 10/10, the programmable EQ helps if you want various high-gain sounds, and the parametric midrange is a godsend.
Seriously, if you want GREAT metal tones on the cheap, GET THIS PREAMP!
Difficult to find something similar to this one-rack unit nowadays... All analog 250 Volt 2x12AX7 tubes preamp with three channels: Clean, Classic distortion and Modern distortion, plus an active EQ with parametric mids and 99 programmable MIDI banks. It also has effects loop and built-in HUSH noise gate. If I ever decide to trade it for another gear, I would need three or four pedals like distortion, EQ, boost and noise gate.