RangeBooster (tm)

by Stephen Grosvenor



Introducing the new Rangebooster treble boost unit by Stephen Grosvenor.

(Author of "A Service Engineer's Guide to the Vox AC30 Valve Amplifier").


Based on a classic vintage treble booster (The Dallas Rangemaster), the Rangebooster uses a vintage Germanium transistor at the heart of the unit to capture the vintage tone.

The secret weapon of many of the legendary great guitarists, the Dallas Rangemaster is now a very scarce item, and as a result, vintage examples of this classic treble booster command very high prices, putting them beyond the reach of mere mortals.

The Rangebooster (tm), provides an affordable solution, and offers the opportunity to capture the magic tone of the vintage units at a great price (125 plus shipping).

The Rangebooster is ideal when used in conjunction with a Vox AC30 (or any valve guitar amplifier for that matter!), for capturing that elusive tone.

Faithful to the original design concept of the Dallas Rangemaster, the Rangebooster offers some modern refinements not present in the original Dallas units. In addition to being a floor pedal (the original Rangemasters were amp top units), the Rangebooster has:

1.Soft switching (Anti-pop).

2.True bypass.

3. An LED indicator.

Quality components are used throughout, including a new old stock vintage selected OC44 germanium transistor, and each unit is hand built in a diecast enclosure. The pedals are constructed using point to point wiring, and a tag strip as found in the vintage Vox amplifiers,to ensure years of trouble-free service. A Duracell battery is fitted as standard, and battery drain for the Rangebooster is very low (less than 3.5mA) meaning that your battery will last a very long time.



The Rangebooster uses an OC44 Germanium transistor (or the military high specification equivalent CV7003), and the unique properties of the OC44 transistor require that each pedal is custom biased/tuned to achieve the optimum performance from the OC44.

The properties of the OC44 Germanium transistors are unique in the way that they respond to input signal frequencies, (gain increases with an increase in frequency), making them ideal for use in a treble booster.  (See below)

          Frequency         Gain            dB

                 80hz                    1                 0dB

                    200hz                  3                 9.5dB

                      500hz                  7.5             17.5dB 

                     1khz                    14               22.9dB

                     2khz                    24               27.6dB

                     5khz                    37.5           31.5dB

                  10khz                  40               32dB

                     20khz                  42               32.5dB


Rangebooster pedals are guaranteed for twelve months from date of purchase.

The Rangebooster costs 125 plus shipping.


(Click here to order via email)

(I will send you a Paypal invoice for the total amount including shipping).


(Click here to see the Rangebooster Plus)