BSM RPA California II "RPA California II" booster replaces the California unit. Whilst the well-proven RPA California primarily highlighted the best possible adaptation to the various pickups by means of an “EQ”, with a view to generating Ritchie’s tone at its very best and under all possible conditions, the new RPA California II now calls for the correct pickups. The California II makes use of the free space gained via a volume pot. This allows for the opportunity to map Blackmore’s tone even with small amps.
The first modification of the Marshall Major's preamp was done in the Marshall factory resulting in a raw and fat tone. You can hear that tone on the "California Jam" recordings from April, 1974. Later on, a new mod was done, resulting in biting, piercing highs with a tight bass, the "Live in London" tone as well as for the rest of the Deep Purple MK 3 period. These two, totally different tones, are integrated into the BSM California II. With the help of the "presence" control pot you can smoothly blend them. All you need to cover the entire MK 3 period, s this one pedal.