Pete Cornish TB-83 Extra

The Pete Cornish TB-83 Extra is a treble boost pedal, the second treble boost Pete Cornish designed and built, dating from the early 1970s and still in production today¹. Where the original TB-83 was made as an interface between Burns Tri-Sonic pickups and the Normal input on vintage Vox AC30 amplifiers, the Extra was created to sit alongside it: Pete Cornish says the TB-83 Extra boost "was required to be louder and with more 'bite' to bring it above other instruments in the live or recording" mix¹.

For a player, that means a boost pedal that pushes a solo forward rather than just lifting the whole rig. It is a hand made unit: each pedal is built individually by Pete and Lynda Cornish, from the etching of the circuit board through to testing, with no other person involved¹.

A louder treble boost built to pair with the TB-83

The TB-83 Extra exists because the original TB-83, on its own, was not always enough. Pete Cornish's product page explains that the Extra was designed to complement the TB-83, giving a louder boost with more bite so a solo part rises above the other instruments on stage or in the studio¹.

The two pedals also chain together, and the order changes what the Extra's volume knob does. Pete Cornish describes the two possible chains¹:

• TB-83 into TB-83 Extra: the Extra's volume control is used to match the level when the pedal is engaged, a conventional boost role.
• TB-83 Extra into TB-83: the Extra's volume control instead drives the TB-83's input, which Pete Cornish says gives "a huge range of sustain and harmonically rich distortion products while overall volume stays virtually constant"¹.

There is also a TB-83 Extra Duplex version, which packs two of the circuits in one box. Each side can be set to a different volume for two degrees of boost, and both can be combined for up to double the gain of each individual effect. Pete Cornish notes it can also be configured as a TB-83 and TB-83 Extra combo in one unit¹.

The controls

The TB-83 Extra keeps its controls simple: a volume knob, a heavy duty all-metal footswitch with a Hi-Brite LED, and a bypass that completely disconnects the pedal from the guitar and amp circuit when switched off³.

The interaction with the guitar's volume control is worth noting for players who roll their volume down to clean up: Pete Cornish's page treats the guitar's volume knob as part of the effect's control set, so the drive into the Extra can be set from the instrument itself³.

Power: 9V DC, 20mA

The TB-83 Extra runs on a 9V DC adapter only. Pete Cornish specifies the supply must be noise free and fully stabilized at 9V DC, capable of supplying 20mA, through a 5.5/2.1mm connector with a negative center pin³.

For the supply itself, Pete Cornish recommends the Voodoo Lab Pedal Power 2 Plus adapter as meeting the criteria, with the BOSS PSA series acceptable if only a single unit is being powered³.

Versions and build

The current TB-83 Extra uses the same circuit board artwork as the original versions, with identical components sourced from the original suppliers³. It is housed in a rugged die-cast box with an easy to set Number Knob, and is available in two finishes: Cornish Black, or a Vintage unpainted style³.

The pedal carries a two year warranty from the date of purchase, covering repairs of any original manufacturing fault, with normal wear, misuse, unauthorized modifications and accidental damage excepted. The warranty is voided if the guarantee labels are damaged or removed, is not transferable, and does not apply to the customer's own connected equipment².

On the maker's 31 March 2026 price list, the TB-83 Extra is listed at 288.38 GBP excluding VAT and 346.06 GBP including VAT for the UK⁴.

How it relates to the TB-83

The original TB-83 is the same 1970s design Pete Cornish has been making ever since, using the original PCB layout and identical components sourced from the same suppliers⁵. It was designed to run first in line after the guitar⁶, and it is the treble booster Brian May used during his time with Queen⁶. Unlike the Extra, the TB-83 takes a battery: the supplied Duracell Procell MN1604 should last up to 500 hours before a noticeable loss of signal, and its current consumption is low, approximately 540 microamps¹.

The two pedals share a maximum output figure of 10dBm and a 92dB signal to noise ratio³⁷, but they are not the same circuit in different boxes. The TB-83 is the interface pedal for Burns Tri-Sonic pickups and the vintage AC30 Normal input; the Extra is the louder, more aggressive second stage built to sit with it¹.

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