BSM designed a new private stock Booster just for the favorite taste of the company's mastermind, Bernd Meiser. It was intended in the first place to emulate the sound of the 1975 studio recording "Ritchie Blackmore's Rainbow", second to achieve Ritchie's early Rainbow live sound that can be heard on the nov. '75 bootlegs, e.g. Bacon Theater, NYC. Furthermore the unit was designed to get this sound from any stock "Bright" input found on classic Marshall amps. The story goes that Blackmore recorded the first songs on the road using different studios and without his personalized Marshall Major amps; just his guitar and the AIWA reel-to-reel with the studio's own Marshall amps. Ritchie used Purple's support act "Elf" (with Dio) as backing band and kept the recordings secretly away from his employing band.
Nowadays it would definitely be a good idea to have either a built in master-volume ampwise or an external power-soak behind to modify the resulting heavy volume. If you want to achieve the sound as closely as possible, use the "historically correct" pickups from the '68-'74 era or the new equivalents in a maple neck ash-body Strat. The booster has been designed especially having these details in mind. Enough for theory! As it turned out in the end the "Studio & live '75" would fulfill all this, but even more. If you have found your personal settings (out of 6 possible combinations) and have the right attitude, you can use it for all classic Blackmore sounds from the late 60s until nowadays if you use a matching amp behind it.
The basic sound can be described as crisp but there's always an attractive little dirty break up noticeable, even in the clean position.
At the left there's a 2-position mini lever switch for "slope". In the down position you'll get nearly the pure and very massive AIWA preamp sound. The upper position emulates a tad of Martin Birches studio filtering, which is mainly a high pass function. You will have the most flexibility using either the booster's high-pass or maybe the pure AIWA sound with the high-pass function built inside your amp (like in Ritchie's Majors) or even without any high-pass, resulting in a very very huge full-range AIWA sound!
On the right there's a 3-position switch for "level". Position 1 is down and nearly clean, position 2 is up and Ritchie's typical 1975/76 stage level. Position 3 can be found in the middle and due to technical necessities has the crunchiest gain. The overall sound is juicy, dynamic and pearly brilliant if you use mainly the bright input of your amp. Of course you can experiment with normal inputs as well. A good amp setting to start with would be Bass # 2, Mid nearly full, Treble #2, Presence #0 and Volume #8.
The magical tone of the "Studio and Live '75" Booster is achieved by the interaction between guitar pickup, booster and amplifier. The Booster should be connected in the signal path directly behind the guitar. The "Studio '75" is powered by a 9V battery or external 9V power supply with a current consumption of approximately 300uA. The average output level is 7 dBm, the maximum output voltage is 5V, when the strings are struck really hard. Note: The negative pole of the battery is ground. All BSM Boosters work true bypass when switched off.