The odd model designation for the ‘MK1.5’ refers to the way that this model sits, chronologically, in between the first version of the Tone Bender, known informally as the ‘MKI’, and the version that Sola Sound began to offer in late-1966, which was officially designated the Professional MKII.

A useful way of looking at this model is by considering it to be a transitional Tone Bender, built between the famous three-transistor ‘MKI’ and Professional MKII models.

1966 Tone Bender MK1.5
1966 Tone Bender ‘MK1.5’

As with the ‘MKI’, the ‘MK1.5’ moniker is one that was only applied to the two-transistor Tone Bender by collectors in modern times. Until Sola Sound released the Tone Bender Professional MKII, their pedals were all known simply as ‘Tone Benders’ (unless branded otherwise).

1966 Tone Bender MK1.5

Early ‘MK1.5’ Tone Benders date to 1965, which means that there is a possibility that it was being produced alongside Gary Hurst’s ‘MKI’ Tone Bender for a while.

Date codes on the potentiometers of surviving pedals also prove that the ‘MK1.5’ was still in production by May of 1966.

Later in that year, Sola Sound would discontinue the ‘MK1.5’ Tone Bender, and offer a modified version of the same circuit under its own, as well as under other company’s brands, as the now-famous Tone Bender Professional MKII.

Circuit board inside a 1966 Tone Bender MK1.5

Compared with the earlier ‘MKI’ Tone Bender, there isn’t much to see inside an original example of a ‘MK1.5’. The small square of stripboard is populated with a ‘textbook’ negative-feedback amplifier circuit, typically with two Mullard OC75 germanium transistors (although some early ‘MK1.5’s’ were fitted with Impex S3-1T transistors instead.)

According to witness accounts, the ‘MK1.5’ was being sold at a variety of different shops across the UK, including by Jennings in Dartford.

During the early stages of the ‘MK1.5’s’ production, the pedals were fitted with a 500k Ω level potentiometer, as opposed to the typical 100k Ω pot that most schematics describe. The larger value level pot extends the lower frequency cut-off, and allows for a bassier fuzz sound. Because Arbiter’s Fuzz Face (released in late-1966) features almost identical parts values, including a 500k Ω level pot, it is very likely that Arbiter used an early ‘MK1.5’ for reference whilst designing their own fuzz box.

Two original MK1.5 Tone Benders
Two original ‘MK1.5’ Tone Benders (Photo credit: C. Nelson)

In 1966, Sola Sound also started acting as an OEM. This meant that, alongside the official ‘Tone Bender’ fuzz boxes, the company was also supplying the same product on behalf of a number of other brands.

The same electronics that were built into the grey (and sometimes gold) Tone Benders, found their way into similar cast aluminium housings, but branded instead for companies such as Dallas [Rangemaster Fuzzbug] & Rotosound [Fuzz Box].

A generic, unbranded ‘Fuzz Box’ featuring a ‘MK1.5’ circuit was also briefly offered in 1966, and the anecdotal evidence surrounding one particular surviving example reveals it to have been originally sold by a music shop in Ireland.

The Beatles, during a recording session in 1966, with a Tone Bender MK1.5
The Beatles were photographed in the studio with a Tone Bender in early 1966. Based on the type of enclosure, and the timing of the photograph, it is almost certain that the pedal in the photo is a ‘MK1.5′ Tone Bender. It’s unknown, however, whether this pedal was actually used for any of the Beatles’ recordings. (Photo credit: Robert Freeman)
Original 1966 Tone Bender MK1.5, formerly belonging to Mick Ronson

One particularly notable user of the ‘MK1.5’ Tone Bender was Mick Ronson. Before going onto global fame in the early 1970s, alongside David Bowie, Ronson played guitar with the Mariners and with the Crestas in the Hull area. Mick briefly lived in London, during the mid-1960s, playing guitar for the Voice, but returned to Hull in 1966 to join a newly-reformed Rats.

It is not known how or from where Mick originally obtained the ‘MK1.5’, but Mick’s pedal still survives, and the electronics in this ‘MK1.5’ date to early 1966.

According to a childhood friend of Mick’s (and also the current owner of his ‘MK1.5’ Tone Bender) at some point in the 1960s the Rats showed up at his address, where Mick gave him the Tone Bender, along with a ‘grey’ JMI/Vox wah-wah and a Marshall speaker cabinet. Mick allegedly did not need the pedals anymore, as he had replaced them with a different fuzz box that he preferred. This sequence of events matches up with Keith Cheesman’s own memory of Mick returning from London with the ‘MKI’ Tone Bender1 that would famously be used throughout his tenure with the Spiders from Mars.

(Many thanks to R. Wilkinson for the photo and history behind this pedal.)

Some songs that featured the ‘MK1.5′ include Him & The Others’ ‘I mean it’, the Transatlantics’ ‘Don’t fight it’, and Downliners Sect’s ‘Glendora’.

Thanks to T. Clemson, G. Gibbs, J. Edmonds & R. Wilkinson

  1. Keith ‘Ched’ Cheesman, interviewed in 2007 for Whotabs [https://www.thewho.net/whotabs/gear/guitar/tonebender.html]

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