Sola Sound Limited was incorporated on November 3rd, 1964,1 and served as the brand under which the Macari’s Musical Exchange chain of shops went on to sell its various electronic musical accessories. The Tone Bender MKII was a three-transistor fuzz circuit that was introduced by Sola Sound in 1966. The circuit closely resembles the earlier two-transistor Tone Bender, but the MKII has an extra transistor gain stage in front.

Sola Sound manufactured the Tone Bender MKII circuit for a number of different companies, as the OEM, during the period of 1966 to 1968. In the interest of clarity, however, this page focuses specifically on the pedal that was formally branded as the ‘Sola Sound Tone Bender Professional MKII’, as pictured. 

1966 Sola Sound Tone Bender Professional MKII

Based on the date codes of surviving Sola Sound-branded Professional MKII’s (and of other closely related Sola Sound fuzz boxes), and also based on the timing of references in the press to the MKII, Sola Sound’s famous model was most likely developed at some point around mid-to-late 1966. The parts selection of surviving Tone Benders from 1966 suggests that the ‘MK1.5’ was discontinued around the same time that the earliest MKII’s were being built.

advertisement for Sola Sound Tone Bender Professional MKII
The Tone Bender Professional MKII, as advertised in the November 1966 issue of Beat Instrumental.

The gradual change in the mixture of electronic components in original Tone Bender MKII pedals reveals that Sola Sound significantly scaled down the use of their own company’s name on the branding of the model, following the introduction of the Vox Tone Bender Professional MKII. This may have coincided with the Macaris’ 1967 takeover of Vox’s retail outlet on 100 Charing Cross Road,2 but that has not been confirmed yet. Some of the earliest known Vox-branded Tone Bender Professional MKII’s were in fact Sola Sound-branded pedals that had the Sola Sound name crudely obscured.

Sola Sound did continue to manufacture the MKII under their own name, alongside the various existing OEM supply chains, but based on the rarity of late-production Sola Sound-branded Tone Bender MKII pedals, this was certainly only done in relatively small numbers.

The various different versions of the Sola Sound-branded Tone Bender MKII are detailed below.

Different versions

The 1966 ‘MK1.5’ conversions/”short board” MKII

Close inspection of some Sola Sound-branded MKII’s reveals that the builder(s) actually modified existing ‘MK1.5’ Tone Benders to the new three-transistor specifications. The graphics of the unbranded ‘Tone Bender’ enclosures were subsequently updated with extra details above the footswitch, denoting the Sola Sound brand & this new model.

These “short board” MKII’s retained almost all of the individual parts of the ‘MK1.5’ circuitry that the pedals started out with, but these parts were rearranged on the old piece of stripboard, to make space for the extra parts that were subsequently added in order to make it a MKII. (Photo credit: J. Logan)

1966-1968 conventional “large board” MKII

Other Sola Sound-branded MKII fuzz boxes were built from scratch, and featured the same circuit layout & parts selection that Sola Sound were already using for the Tone Benders they were supplying, as the OEM, to Marshall, Rotosound & Dallas.

This particular pedal has a relatively early selection of components, and dates approximately to late 1966/early 1967. The shade of grey paint on this “large board” (as it is sometimes described by collectors) MKII was also used for Marshall SupaFuzz pedals that were built at the same factory, at the same time, and using the same mixture of germanium transistors & parts. The Sola Sound-branded Tone Bender MKII, built with this “large board” was apparently built in relatively small numbers compared with the Vox & Marshall-branded MKII, until the Tone Bender MKII circuit was finally discontinued in 1968. (Photo credit: J. Roth)

1966 two-transistor MKII

This particular Sola Sound Tone Bender MKII is somewhat of an anomaly. The type of sandcast enclosure in which the pedal has been built, and the shade of grey of its paintwork, are both consistent with the 1966 ‘short board conversion’ MKII’s (as described earlier on this page). What makes this pedal unusual is that the circuit board has not actually been updated to the three-transistor specification of the Tone Bender MKII — this pedal is a two-transistor ‘MK1.5’ housed inside a ‘Sola Sound Professional MKII’ branded enclosure.

It’s possible that this is an example of a mistake having been made at the factory where the pedals were built, and that an engineer may have forgotten to update the pedal. It’s also possible that, upon testing the two-transistor circuitry at the factory, this pedal was determined to perform and sustain well enough not to warrant being modified. At present, we can only speculate as to the origins of this unusual Tone Bender MKII. (Photo credit: H. Barclay)

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I welcome any comments, feedback, queries & corrections in relation to the Fuzzboxes.org project. Please get in touch via this contact form (or on the ‘contact‘ page).

Much of our understanding of the development of 1960s fuzz boxes comes from analysis of surviving pedals themselves, and so photos of pedals belonging to readers are particularly useful in furthering this research.

If you would like to contribute pictures of 1960s-era guitar effects to Fuzzboxes.org, then feel free to send in any pictures via the uploader below. Photos are greatly appreciated, and any submissions are not published on this website without advance agreement with the contributor.

    1. Gov.uk, Companies House [https://find-and-update.company-information.service.gov.uk/company/00825826]
    2. Beat Instrumental, February 1967, p. 25