BSM HS-S Treble-Booster
As a follow-up of the germanium-transistor loaded early issued Hornby-Skewes Treble Booster, now the late 1969 version, equipped with one of the earliest silicon transistors available, appears on the scene under the BSM brand HS-S. The HS-S was Ritchies favourite box for studio recordings like the famous 1971 "Machine Head" or the later 1974 "Burn" sessions and even on Ritchies solo debut "Ritchie Blackmore's Rainbow". The HS-S in front of a Vox AC30 gives you the unique sound of the wellknown rock hymn "Smoke on the water". Compared to its forerunner, the HS-C sounds milder with more mid-range with the guitar´s volume pot fully openend, a little bit similar to a WahWah sound. The long yearned new edition, now issued under the name HS-S from BSM, includes the same silicon transistors as the original version.
Almost all British rock guitarists using single coil pickup guitars, used a germanium Treble Booster from the late 60's to the mid 70's. By the end of the seventies, the Treble Booster was replaced by a new circuit from Japan, the socalled Tube Screamer and other similar overdrive circuits. These were based on the old Treble Boosters and therefore had a very similar frequency response. The treble boosters on the other hand, sadly fell into oblivion despite their unique and inimitable sound. The HS-S Treble Booster has been designed for single coil or humbucking pickups with a relatively low/medium coil inductance, such as pickups in Fender, Rickenbacker or Gibson guitars. In conjunction with this pickups, the HS-S with the volume control of the guitar turned up to the max, produces a fat, biting and penetrating lead sound, minus any shrill characteristics. By lowering the guitar's volume control, many shades of crunch can be easily dialed in. Another thing to consider is that when a guitar amp's volume is turned up and reaching saturation, the power amp normally begins to mute the highs, which results in a duller sound. At an amp's full tilt, the HS-S Treble Booster allows a more transparent tone, covering the entire frequency range to shine through. With vintage amps like the Fender Deluxe, Fender Bassman, Vox AC30, Marshall 100w or Marshall Major it is amazing what effect the use of a good treble booster has.
It is also of interest to note that Ritchie Blackmore used a standard VOX AC-30 amp played on the "Machine Head" recording session. The HS-S Treble Booster is inserted between guitar and amplifier, not into the FX loop. The magical tone is achieved by the interaction between the guitar pickup, treble booster and amplifier. The unit is powered by a 9V battery with a current consumption of aprox. 550 uA. The average output level is 6dBm, the maximum output voltage when the strings are struck really hard is 5V max.