RPA Special Booster

BSM RPA Special Booster

The BSM RPA Special Booster is a combination of Ritchie Blackmores AIWA reel-to-reel tape recorder preamp stage plus the high-pass treble booster function from Blackmores hot-rodded Marshal Major amp, to emulate Ritchies post '74 sound with any standard amp. In 1974, right before the start of the "Burn" tour, Ritchie Blackmore changed his live setup. First and foremost, he wanted to play live with an echo effect and made the AIWA TP-1011 reel-to-reel tape recorder his first choice. This unit offered the typical 2/3 seconds echo repeat, perfectly matching Blackmores natural beat. Additionally, Ritchie Blackmore used the integrated microphone pre-amp as a booster, and with this his beloved Hornby-Skewes treblebooster he used for many years was not longer needed and was sent into retirement. The necessary trebleboost function (from a technical point of view a "highpass" function), was built into his heavily modified Marshall Major 200 amp. The Major amp now received a cascaded pre-amp stage with a new, non-bridged cathode resistor at one of the triode stages to prevent to much overall gain. At the final stage, Blackmore's Major amp was loaded with four pre-amp tubes (incl. the driver tube), instead of the factory stock three tubes. Further on, the 250Ohm screen-grid resistors of the four KT88 power tubes were changed to 1kOhm and the two 10uF electrolytic filter capacitors of the BIAS power supply were replaced by two 47uF (160volt minimum) caps. Blackmores tech, did several fine tunings over the years to Ritchies Major amp, because Ritchie experimented with several pickups in his guitars as well as with several new ideas of his trademark sound.

Not everybody owns such a heavily hot-rodded amp, and if so, for sure it will not have the correct highpass cutoff frequency! So BSM had the idea, to not only rebuild the AIWA preamp stage, but to also integrate the important highpass function with the original cutoff frequency. The BSM RPA (Ritchies Pre Amp) emulates both typical soundshaping functions in only one stompbox - another BSM first ! The RPA is equipped with a gain control, to dial in the best possible balance for the use with different amps and pickups. The EQ control allows a tonal fine tuning for the use of the RPA with different pickups, amps and speakers for an optimum in versatility. Depending on the pickups, the sweet spot of the EQ control is located between 11:00 and 01:00 o'clock. Another highlight of the RPA was more or less created by accident: with the gain pot fully opened, and the EQ control completely closed, you receive the authentical Blackmore sound from the great "Machine Head" album or Ritchie Blackmore's "Rainbow".

As a soulmate for the RPA, you can use any mild sounding amp with a good master control function. Plug it in front of the CLEAN or CRUNCH channel, but don't use the high-gain or distortion channel ! Because of the EQ control, you can use all kinds of pickups, from the brilliant sounding low-gain Fender Custom Shop 69' (aka "Abigail Ybarra" pickups) up to the thundering Seymour Duncan "Quarterpounds".

The RPA Special Booster is inserted between guitar and amplifier, not into the FX loop. The magical tone is achieved by the interaction between guitar pickup, booster and amplifier. The unit is powered by a 9V battery with a current consumption of approx. 350 uA. You can also power the unit, using the external "Boss style" (2.1mm - tip negative) DC jack, the internal battery will shut off automatically then. The average output level is 10dBm, the maximum output voltage when the strings are struck really hard is 6V max. Because of the external DC jack, you can power the RPA with 9, as well as with 18 volts for more headroom.
Note: The negative pole of the battery is ground!

Booster Image: RPA Special Booster

Here is a soundclip, recorded by Leon from the Netherlands

And another one from Janeck Dzugan, his Strat is loaded with Lace Sensor "Hot Gold" pickups and a Lace Sensor "Silver" in the bridge position, besides this, he uses Blackmore´s techs MTC circuit.

Here a new track from US Metal guitarist Joe Stump aka „The Shredlord“ from his new solo album. Joe have loaded his Strat with a “Spice Box” and the “Munich ´77” pickups from Leosounds in Germany and used as preamp/ booster the RPA unit.

If you have any questions concerning our products, especially the BSM RPA Special Booster, our tech-head and mastermind Mr. Bernd C. Meiser would be happy to talk to you. So don't hestitate any longer and send him an email to info@treblebooster.net or use the contact form to contact him.


Dear Bernd, yesterday I play with the RPA......this pedals is amazing. I love it! Together with the fuzzbender I can achive all the tone that I need. Your pedals is super! Regards
Francesco Carraro
Hallo Bernd, jetzt mal ehrlich: Ich bin sehr "anstrengend" wenn es um TONE geht....und sehr kritisch. Ich habe so ziemlich alles an Bodentretern unter den Füßen gehabt. Auch als Dein Endorser besitze und spiele ich: den VX-T & den Ambassador. Gespielt habe ich auch den RM und den Spectrum und den Fuzzbender. Der Amba war bis jetzt mein absoluter Booster-Favorit....aber der RPA ist so ziemlich das Beste, was mir in letzter Zeit auf das Board gekommen ist! F-A-N-T-A-S-T-I-S-C-H!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Ob wenig oder viel Gain, ob EQ mittig oder scharf.....das Teil ist der Hammer mit meiner Esquire und meinen Amps! Ein Riesenkompliment an Dich! Ich bin hin und weg! Den bekommst Du nicht wieder..........
Till Hoheneder
Dear Bernd, I have a RPA. No RPA, no life! Sincerely
Hirose Sooshi
Hello again Bernd, just to let you know I now have the RM model (from Musicground), Its sounds Great, Fantastic raw sound up full, down to dirty crunch and then cleans up beautifully. A joy to play and hard to put down !! Thanks again for your kind help and a wonderful product. My very best wishes
Hallo Bernd, ich habe den RPA bei meinen beiden letzten Gigs eingesetzt. Zur Einstellung des Engl Savage 120: Man braucht schon den Gain-Kanal (mit einer Strat (Lace sensor Pick-ups am Hals und Steg)). Lead Gain und Gain bei 10.30 Uhr. Bass bei 10 Uhr, Middle 13 Uhr, Treble 13 Uhr, Master 13.30 Uhr.Contour in. Smooth in. Beim Delay auf die Erdung achten, kein Netzteil. Oder, wie ich es mache, einschleifen. Resumee: Dein bestes Pedal bis jetzt!!! Super! Beste Grüße
Heiko Rust
Hi Bernd, I bought the RPA a half year ago and I can only say: I've got the holy grail of the Blackmore sound chain! It's absolutely great, the RPA! My sound is so much better than before! This is what I've always missed, but now I have this magical tone too. It even works with digital amp simulators like the POD 2.0 and the Roland cube 30! A few days ago I recorded the christmas song 'Silent Night', in Blackmore-style. When you'd like to hear it: soundclick.com/share?songid=7167812 It's: guitar (Fender Strat with Lace sensors) / RPA / POD 2.0 / soundcard PC. What do you think of it? Thank you so much for making this device! Merry Christmas and a happy new year! Edwin Kosters from Holland
Edwin Kosters
Hallo Bernd, der RPA ist der Hammer! Transparent, fett und variabel. Den werde ich neben dem RG behalten. Gruß,
Frank Foullois
Bernd, now I have used RPA for some time and I must say that I like it more and more ! Since getting RPA I haven´t plugged my Tape Deck anymore on, now RPA is doing its duties and it is becaming one of the essential elements in my sound. Thank you for creating RPA !
Kari Rastas
Hi Bernd, I bought a RPA unit a few weeks ago and it sounds damn good! I tried it with SSL7t, YJM, and humbuckers. It always sounds great. I prefer with YJM, because when I roll back the volume pot, I have that incedible strat twang ! Thank you very much ! Best regards, Janeck
Lieber Bernd, ich möchte mich an dieser Stelle nochmals für den wundervollen RPA Booster (Nr.: 2268) bei Dir bedanken, den ich in Frankfurt am 12.03. bei Dir kaufen durfte! Was hier bei mir vor Ort mit meinen Amps passiert, ist nicht in Worte zu fassen!!! Ich bin ja schon so manches gewohnt (Fireball Nr.:1838 / HS Nr.: 122), aber der RPA hat mir echt die (nicht vorhandenen) Locken vom Kopf geblasen!!! WAHNSINN!!! Egal ob vor einen 1959 Plexi Marshall, einem JCM 800 2203, JCM 900 2100/4100/4500 oder Hiwatt Custom 100, ja sogar vor diversen Fender Amps ist Dir meiner Meinung nach hier der beste Wurf ever gelungen (wenn Du das anders siehst, schick mir bitte das entsprechende Gerät zu!)!!! Die Feinabstimmung von EQ und Gain ist einfach super gut - Hut ab! Ich habe noch keine Einstellung gefunden, die schlecht klingt! Hier geht einfach immer die Sonne auf! Meine Lieblingseinstellung ist: Gain auf 12h und EQ kurz vor 11h, Fender CS Strat, angecrunchter Marshall - fertig! Unglaublich... Vielen vielen Dank und schöne Grüße aus Bergisch Gladbach bei Köln, Dirk Stüber P.S.: Meine Nachbarn wissen zwar nicht, wer Bernd C. Meiser ist, aber sie hassen ihn!!! ;-) Meine Frau sieht das übrigens auch so und will Dich wegen permanenter Abwesenheit ihres Mannes (Keller) verklagen!!! lol
Dirk Stüber
Hallo Bernd, der RPA Special Booster ist der ultimative Booster für mich. Mit dem Studio 75 lässt sich der heutige Sound von Ritchie besonders gut nachahmen, da er eher einen cleanen Sound bei behält. Der RPA allerdings öffnet mir noch viele Türen mehr. Von Machine Head bis Perfect Strangers bis hin zur letzten Rainbow Inkarnation in den 90ern. Mit den Einstellungen am Amp (ENGL Sovereign 50) und der korrekten Einstellung am Booster kommt man an jeden Sound von 1972 - 1997 dran. Bin wirklich begeistert. Der Studio 75 ist das ultimative Gerät, wie ich vorab schon erwähnte, um den aktuellen Sound zu bekommen. Mit den beiden Boostern bin ich also top ausgestattet. Danke dir.
Bernd, Just to follow up, I ordered the RPA Special from Steves Music in New York, received pedal 2 days later and I ABSOLUTELY LOVE IT! I have played for over 30 Years and have refined my tone to near perfection but was never 100% satisfied, your RPA Special has finally got me to my goal of my perfect tone, THANK YOU!!! Respectfully,
Todd Fohrman
Dear Bernd! I received the pedals. I don’t have words. It’s simply very cool! Small boxes make a great sound. CM 71/73 is very transparent and brilliance. Strat sounds like it must do. It’s very interactive with Volume control of guitar. RPA Special is more distorted and fatness, but very singing. When EQ closed, it’s really Machine Head’s sound. I tried it with Marshall JVM 215C combo in clean channel. It’s really like JCM 800 and 4x12 Cab. Ambassador is very useful. Each position of controls makes new sound. I tried it with Ibanez TS-9DX (Keely mod), Empress Effect Multidrive and Wampler Pinnacle II. My guitar is ready to explode. You are magician. Many, many thanks! Nick, Moscow