One of the most well-known versions of the Sola Sound Tone Bender MKII is the one that was supplied, by Sola Sound (via Macari’s Musical Exchange), to Vox. According to original owners’ testimonies, Vox was already selling Sola Sound-built Tone Bender fuzz boxes by early 1966, but these pedals weren’t formally branded as Vox products yet [see: Tone Bender ‘MK1.5’].

By early 1967, Sola Sound had suspended (or at least scaled down) printing their own brand name on the Tone Bender Professional MKII, and they started branding the pedals as Vox Tone Bender Professional MKII’s instead. It’s possible (but unconfirmed) that this is connected to the Macaris’ takeover of the Jennings/Vox shop at 100 Charing Cross Road, which was also reported in early 1967.1

The transition from Sola Sound to Vox was purely a branding/business decision, and the Tone Bender MKII remained functionally the same. The earliest known Vox-branded Tone Bender MKII’s have actually had the ‘Sola Sound’ name crudely obscured from the silkscreened graphics with a black bar, and replaced with ‘Vox’.

early production Vox Tone Bender Professional MKII
Early Vox Tone Bender Professional MKII, circa 1967. (Photo credit: G. Sheard)

The Vox Tone Bender Professional MKII pedals were painted in silver Hammerite, and instead of Bulgin ‘chicken head’ knobs, these pedals now featured tall silver-topped knobs (similar to the current Cliff K5 knob). Those silver-topped knobs were the same style that Sola Sound would continue to use on all of their effects pedals (including the Colorsound range) until well into the 1970s.

Earlier examples of this version of the Vox MKII featured a triplet of Mullard OC75 transistors, while late-production examples, c. 1968, feature OC81D transistors. Earlier examples were built with slightly larger value input & output capacitors; and the very last of the Vox MKII’s were built without an input capacitor at all. Some very early Vox Tone Bender MKII pedals featured Impex S3-1T transistors. These ways in which the circuits inside Vox Tone Bender MKII pedals changed over the course of production are merely an insight into Sola Sound’s development of the circuit. The shift from OC75 to OC81D transistors, for example, is something that can also be observed in the MKII Tone Benders that Sola Sound were supplying to Marshall and to Rotosound, at the same time as these Vox-branded pedals.

1967 Vox Tone Bender Professional MKII
1967 Vox Tone Bender Professional MKII

The above statement shows Vox confirming an order of 100 Tone Benders from Sola Sound. The agreement to supply Vox with their own, formally-branded, Vox Tone Bender MKII lasted from approximately early 1967 until mid-1968, and based on the relatively high number of surviving examples, it is likely that many orders like this one were filled for Vox, and that many hundreds of Vox Tone Bender MKII’s were built. (Credit:

The Tone Bender MKII was finally discontinued in 1968, but Sola Sound’s partnership with Vox did not end there. The demise of the MKII resulted in Sola Sound’s invention of the Vox Tone Bender MKIII, and the agreement for Sola Sound to manufacture fuzz boxes for Vox lasted until the late 1970s.

Circuit board inside a 1967 Vox Tone Bender MKII
Internals of an OC75-transistor Vox Tone Bender Professional MKII, c. 1967.
  1. Beat Instrumental, February 1967, p. 25

2 thoughts on “Vox Tone Bender Professional MKII

  1. Which input capacitor was removed on later builds … the 10 nF one or the 4.7 uF one? I think it must have been the 10 nF otherwise there’s no DC blocking capacitor on the input. Thx.

    1. Yep, you’re quite right. It’s the cap running from input to ground. During the period that Sola Sound was making the OC75-transistor version of the MKII for Vox, the cap in that position was actually 15nF. By the time they were making OC81D MKII’s, they reverted to using 10nF, before dropping it altogether.

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