Background

The Mosrite guitar company was founded in Bakersfield, CA, in 1956, by brothers Semie & Andy Moseley, thanks to an investment from Ray Boatright. The name, ‘Mosrite’, was a portmanteau of these two entities. It wasn’t until Mosrite assembly-line inspector, Eugene Moles, met Nokie Edwards in the early 1960s, that the company became involved with the Ventures, and ultimately started offering the various signature models.1

Ed Sanner was reputedly involved with Mosrite by 1965, developing circuits for a range of amplifiers that they planned on offering, in addition to the guitars.2 Sanner recalls supplying steel guitar player, Leo LeBlanc, with a custom-made fuzzbox, and subsequently Semie became interested in manufacturing this as what would eventually become the Mosrite Fuzzrite.3

Advertisement for the Mosrite Fuzzrite

It is unknown exactly when the Fuzzrite came on the market. Over the course of several years, the Fuzzrite underwent numerous cosmetic changes, as well as technical changes to the circuit. Specific features of the Fuzzrite (detailed below) correlate with the sequence of date codes stamped onto the potentiometers. This information allows us to form a wider timeline of production of the Mosrite Fuzzrite, with which we can place specific surviving pedals in chronological order. It also suggests that production of the Fuzzrite began at some point in mid-to-late 1966, and continued through 1968, presumably until the time when Mosrite infamously went bankrupt.

Mosrite Fuzzrite, c. 1966-67

There are two distinctly different versions of the Mosrite Fuzzrite that were being built during the period of 1966-1968. Earlier Fuzzrites were built with a set of 2N2613 & 2N408 germanium transistors, while later versions used silicon transistors, across a variety of different construction methods.

For a long time, there was a common belief circulating the various Internet forums that the earlier, germanium-transistor Fuzzrites were built in considerably smaller numbers than the silicon versions. Ed Sanner recalled Mosrite having shipped “around 200 [Fuzzrites]” before they realised that the innate temperature-sensitivity of germanium transistors was leading to problems with the fuzz sound.4 In another interview, at some point in the early 2000s, Sanner also gave the number of germanium-transistor Fuzzrites produced, as ‘250’, and cited the same problem with regards to temperature-sensitivity as being the catalyst for the move to the silicon-transistor design.5

Extensive study of the technical details of the germanium version of the Fuzzrite casts some doubt over this narrative. The following section explores the development of the germanium-transistor Fuzzrite in greater detail, and furthers the possibility that this ‘temperature-sensitive’ model is not quite as rare as some dealers and collectors like to think.

Tech specs

Mosrite Fuzzrite (perf board version), c. 1966

Internals of 1966 Mosrite Fuzzrite, assembled on perfboard

The earliest known version of the Mosrite Fuzzrite was built point-to-point, on perforated circuit board. These Fuzzrites are among the rarest versions, and as a result, there’s only very limited data available about them. (Photo credit: J. Roth/jermsfuzz)

The 100nF input, output & coupling capacitors on these perfboard Fuzzrites were manufactured by Cornell Dubilier. CDE capacitors have yet to be seen in any other version of the Fuzzrite.

There are only two sets of potentiometer date codes known from the very small sample of surviving perfboard Fuzzrites, and both sets read the 23rd week of 1966.

The bushing of the perfboard Fuzzrite’s footswitch feeds through the circuit board, and a small block of wood was secured around the switch, acting as a physical spacer between the circuit board and the enclosure. A sheet of clear plastic runs across the underside of the board, which also helped to prevent a short-circuit.

Mosrite Fuzzrite (phenolic paper, “reversed” version), c. 1966-1967

Internals of 1966 Mosrite Fuzzrite

The version of the Fuzzrite that succeeded the apparently short-lived perfboard Fuzzrite featured the same circuit, but differs in that the parts were assembled on a dedicated phenolic paper board. The construction style was virtually identical, in that the components were still soldered directly to one another, without the aid of any printed tracks, eyelets, or turrets on the boards. (Photo credit unknown)

Early examples of this version of the Fuzzrite were built with the parts of the board facing outwards, and came with the footswitch mounted ‘through’ the board, as per on the perfboard model. Fuzzrites with the parts facing outwards (sometimes described as ‘reversed’) maintained other similarities with the perfboard model, such as the clear plastic spacer between the enclosure & board, and the wooden block between the footswitch & board.

Mosrite Fuzzrite (phenolic paper version), c. 1966-1967

Internals of 1966 Mosrite Fuzzrite

At some point in late 1966, Mosrite flipped the circuit board around, and began building what would go on to be the most commonly seen version of the germanium-transistor Fuzzrite, until around late 1967. With the parts facing inwards, there was apparently no need to use the plastic spacer or the wooden block to isolate the electronics from the casing anymore.

Fuzzrites built on the phenolic board featured the same circuit as the perfboard version, but the choice of input, output & coupling capacitors changed over time. Instead of the CDE 100nF capacitors, seen in the perfboard Fuzzrites, the pedals built on phenolic boards initially had red molded 100nF’s.

By early 1967, the circuit of the Fuzzrite was changed slightly, as the 100nF capacitors were replaced with 50nF’s (and, briefly, with 47nF’s). At least two different types of polystyrene film capacitors were used during this period of construction, but Mosrite apparently soon settled on fitting 50nF ceramic capacitors for the remainder of the run of germanium-transistor Fuzzrites, until 1968. (Photo credit: unknown/A. Souleyman/Psycho*Daisies)

Known potentiometer date codes in the earlier, ‘reversed’, version of the phenolic board germanium-transistor Fuzzrite range from the 15th through to the 47th weeks of 1966. Known date codes in the pedals, built with the parts on the boards facing inwards, range from the 28th week of 1966, through to the 12th week of 1967. The range of dates in these two versions of the Fuzzrite overlap slightly, and because the type of graphics on the enclosures (detailed below) also overlap, we can’t conclusively rule out whether the ‘reversed’ and ‘conventional’ phenolic board Fuzzrites may have briefly been built in parallel, in around late 1966/early 1967.

Mosrite Fuzzrite (eyelet board version), c. 1967-1968

Circuit board from a 1967 Mosrite Fuzzrite

The youngest known version of the germanium-transistor Fuzzrite was developed approximately in mid-to-late 1967. By this point in Mosrite’s production, the individual components were no longer being soldered directly to one another by their leads, and instead, the Fuzzrites were being assembled on a smaller eyelet board. (Photo credit: J. Reeves)

One particular surviving eyelet board Fuzzrite has had the date ‘12/67’ crudely engraved into its battery cover, and this information reveals the time by which the model was already available in the shops.

For a brief period, during production of the eyelet board Fuzzrite, Mosrite used CTS potentiometers (prefix ‘137’). These CTS pots date to 1965, and this has led to some confusion when dating vintage Fuzzrites. Features of the eyelet board Fuzzrite such as the ceramic 50nF input, output & coupling capacitors, the black plastic footswitch, and the ‘®’ symbol on the graphics, are all consistent with the youngest of the ‘paper phenolic’ Fuzzrite (dating to 1967). Additionally, there are identical Fuzzrites built on eyelet boards that apparently have typical Centralab potentiometers from a different parts supply, and those potentiometers have date codes ranging between the 1st & the 10th weeks of 1968.

Even though some germanium Fuzzrites were fitted with potentiometers from 1965, the pedals themselves are identical to the ones built during the period between late 1967 and early 1968. There is no evidence to suggest that the Fuzzrite existed prior to 1966, and the date codes from surviving vintage pedals reveal that Mosrite were still building Fuzzrites with the germanium-transistor circuit at least by March 1968.

Internals of two late-production germanium Fuzzrites

The two Fuzzrites above are the later variety of the germanium-transistor model, and have both been assembled on the eyelet board. The only difference between them is that the unit on the left (photo credit: J. Reeves & M. Seppi) has been fitted with CTS potentiometers dating to 1965, while the unit on the right has the typical Centralab pots, dating to early 1968, and which follow the established sequence of date codes in Fuzzrites. The presence of 1965-dated potentiometers in Fuzzrites of this variety does not suggest that this pedal was built before 1966, because everything else about the pedal is consistent with the models built around 1967-1968.

Mosrite Fuzzrite (silicon transistors), 1968

Three different versions of the silicon-transistor Fuzzrite (Photo credit unknown)

The germanium Fuzzrite was discontinued in 1968, and replaced with a silicon-transistor version of the same circuit. Silicon Fuzzrites were manufactured in very large quantities, in a relatively short space of time.

Early silicon Fuzzrites were built with the same construction style as the last of the germanium units, where the components were assembled on an eyelet board, upon which the footswitch was mounted too.

Later silicon Fuzzrites were built on similar eyelet boards, but these differed from the earlier silicon model in that the footswitches were no longer being mounted directly to the circuit boards. A large stash of apparently ‘new old stock’ eyelet boards of this type were supposedly uncovered by Andy Moseley in more recent years (along with leftover Fuzzrite enclosures), and Moseley went on to assemble and sell these pedals decades after the original production run. Many of the surviving Fuzzrites with this type of construction were actually only built & sold in the 21st century.

Another version of the 1968 silicon-transistor Fuzzrite was built by a combination of Mosrite and Sprague (who supplied the electronics). It’s unclear whether these Fuzzrites, with their circuits encased in orange ‘modules’, were direct successors to the Fuzzrites built on eyelet boards, or perhaps whether they were built in conjunction for a while. Date codes on Sprague’s encapsulated circuits show that they were already being supplied to Mosrite by July 1968, and that production continued at least until October of that year.

Analysis of the Fuzzrite’s graphics

Three Mosrite Fuzzrites, with different versions of the silk screened graphics (Photo credit: K. Higasayama/kunihito1226; S. Lee/freddy_von; unknown)

Mosrite produced at least three different versions of the graphics that the Fuzzrites’ enclosures were printed with between 1966 and 1968. The first two versions are almost indistinguishable, other than that the typeface for the ‘FUZZrite’ lettering differs. The third version was the same as the second, but featured the ‘®’ symbol, denoting that the Fuzzrite was now a registered trademark of Moseley’s. (Photo credit: K. Higasayama/kunihito1226; S. Lee/freddy_von; unknown)

The version of the phenolic paper board Fuzzrite, built with the components facing outwards (i.e. ‘reversed’) has been discovered in enclosures printed with both first and second version graphics. Fuzzrites, built with phenolic paper boards that came with the parts facing inwards, have been seen in enclosures bearing first, second, and in third version graphics. It appears that by the time that the third version of the graphics (with the ‘®’ symbol) was developed, Mosrite had ceased building germanium-transistor Fuzzrites with the parts facing outwards, and that Mosrite had also replaced the 100nF molded capacitors with the various different types of 47nF & 50nF parts.

Production numbers

The exact number of Fuzzrites that were built by Mosrite during their initial run between 1966 and 1968 will likely never be known exactly. It is fairly safe to say, however, that because the original germanium-transistor Fuzzrites resurface on the used market at roughly the same rate as the 1968 silicon-transistor model, production numbers of the germanium Fuzzrite were probably similar. After all, the germanium Fuzzrite was also in production for a lot longer than the silicon version was (with the latter having only been developed in 1968, shortly before Mosrite’s bankruptcy).

A very large proportion of 1960s-era fuzz boxes have not survived over the decades. The steel enclosures of the Fuzzrites were particularly susceptible to rusting, and the proximity of the pedal’s battery to the circuit board, particularly in the germanium Fuzzrites, meant that there was also a risk of ruining the electronics if a battery was left to leak inside for too long. The Fuzzrites that have not only survived, but that have also resurfaced on the Internet, make up a very small proportion of all that were ever manufactured. Certainly, there were more than 200-250 germanium Fuzzrites built, because at the time of writing, I already have photos of 91 surviving examples of the model.

Future of the Fuzzrite

Mosrite went bankrupt in late 1968, and formally ceased doing business by 1969,6 but this was not the end of the Fuzzrite. Ed Sanner released a variation on his original design, called the ‘Nu-Fuzz’, which was built by Sierra Electronics (and later Rosac Electronics) in reasonable quantities through the 1970s. Various members of the Moseley family would also go on to reissue the Fuzzrite at various points in the years & decades that followed.

The Mosrite Fuzzrite also inspired copies at the time, taking the form of ‘Manny’s’ Fuzz, as well as a non-descript fuzz box manufactured in New York by Aul Instruments, which was one of Mike Matthews’ (Electro-Harmonix) very first forays into the guitar effects pedals domain. Fuzz boxes based off the circuits of both the germanium and the silicon-transistor versions of the Fuzzrite continue to be built by professionals and by hobbyists to this day.



  1. Price, Robert [https://web.archive.org/web/20080712034122/http://www.bakersfield.com/static/FP/baksound/mosrite.htm]
  2. Shade, Bob [http://www.hallmarkguitars.com/pedals/nu-fuzz.shtml]
  3. Halterman, Del, Walk-Don’t Run – The Story of The Ventures, Lulu, 2009, p. 134
  4. Halterman, Del, Walk-Don’t Run – The Story of The Ventures, Lulu, 2009, p. 134
  5. http://www.dominocs.com/Library/FuzzriteQA.html
  6. Price, Robert [https://web.archive.org/web/20080712034122/http://www.bakersfield.com/static/FP/baksound/mosrite.htm]