ISP Technologies Theta Preamp Pedal

The ISP Technologies Theta Preamp Pedal is a high-gain preamp pedal that carries the preamp and distortion sections of the ISP Technologies Theta amplifier down to a foot-pedal format. Premier Guitar's announcement put it plainly: the pedal "brings the full performance of the High Gain section of the Theta amplifier and Theta Rack-mount Preamp down to a foot pedal"¹. Guitar World reported that it debuted at Winter NAMM 2013, featuring the full preamp and distortion sections of the rack mount preamp shrunk down to fit in a pedal chassis².

Where it came from

The pedal comes from ISP Technologies' Theta line. The company's page for the rack mount THETA PreAmp describes the concept as "like having two low-noise, extremely high quality preamp pedals at the input of the amplifier"⁴. The pedal version takes that same two-section design and puts it on the floor. Guitar World, covering the NAMM debut, described the rack unit as a preamp with gain and distortion sections, and said the famed gain and distortion of the THETA Preamp was now available in a pedal².

Gain and the two-section design

The headline figure is gain. ISP Technologies says the pedal delivers over 160dB of gain when the Pre-distort Preamplifier and High Gain Distortion sections are used together, which the company describes as outrageous gain³. Premier Guitar's press release tied that figure to the Theta amplifier series as a whole: "The trademark sound of the Theta amplifier series is over the top gain and sustain with over 160db of gain on tap and incredible tone shaping flexibility"¹. Guitar World's take at the debut was shorter: "Try 160dB of ear shattering gain"².

That much gain needs noise control, and the pedal has it built in. Guitar World reported that the pedal includes a built-in ISP Decimator circuit, and said "That much gain is only usable because of the built in ISP Decimator circuit"². Players who want to see what a dedicated noise reduction unit does alongside a high-gain pedal can read more on the site's Noise Gate Pedals page.

Controls and ways to use it

The preamp section carries its own tone controls, independent of the high-gain stage. Premier Guitar listed the preamplifier section controls as Gain, Bass, Midrange boost/cut Level and Midrange Sweep from 300 to 3KHz, Treble and Preamp Level¹. ISP Technologies adds that the Pre-distort Preamplifier stage's 3-band EQ can be used on its own for tone shaping independent of the high-gain stage³.

The two sections can be combined or used separately. Premier Guitar's release says the Preamp section can be used stand-alone for clean tone shaping, used to overdrive the front of the Theta High Gain distortion stage, or run with the distortion section alone¹. Guitar World described the same three arrangements: preamp alone, distortion alone, or the preamp overdriving the distortion section².

Power

The pedal runs from a 9V AC power supply, which is included³. ISP Technologies also notes the pedal uses a +/-15-volt power supply internally, which the company says gives it an amazing amount of headroom for more dynamic tones³. The AC input matters for pedalboard planning: a 9V AC supply is not interchangeable with the center-negative DC supplies most pedals use, so it cannot share a standard daisy-chain output.

Theta Preamp Pedal and Theta X

ISP Technologies later expanded the Theta line with the Theta X, a larger floor unit. RockBoard's PedalPedia entry describes the Theta X DSP as a floor controlled guitar system with a fully programmable digital Theta preamp, a Vintage preamp, studio quality effects processing and a built-in full function precision tuner⁵. The maker's description quoted there says it is not a modeling processor and that the preamp section delivers more tone shaping and gain flexibility than any other processor available⁵. In short, the Theta Preamp Pedal is a single-purpose two-section preamp pedal, while the Theta X is a programmable digital floor system with effects and a tuner built in.

The Theta line also reaches the site's pages on the ISP Technologies Theta Pro DSP and the ISP Technologies Empyrean, a later Michael Sweet-designed preamp pedal that also runs on 9VAC power.

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