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ASTERIA PREAMP DRIVE MK. III

1

PROJECT NAME

ASTERIA MK. III

BASED ON

EFFECT TYPE

PROJECT SUMMARY

DOCUMENT VERSION

Catalinbread

®

 Formula 55

An adaptation of the Fender

®

 Deluxe 5E3 amplifier from 1955, a classic low-wattage amplifier noted for 

its harmonically-rich breakup that can be achieved at low volumes.

Overdrive / Amp Emulation

1.0.1 (2020-12-10)

Actual size is 2.3” x 1.86” (main board) and 1.78” x 0.87” (bypass board).

BUILD DIFFICULTY

Intermediate

This documentation is for the 

Mk. III

 version of the project. There is also a 

Mk. I

 version, based on 

the Formula No. 5 V1, and a 

Mk. II

 version, based on the Formula No. 5 V2. While the names are 

similar, the circuit and part numbering are different. Please be sure your PCB is labeled “Asteria Mk. 
III” before proceeding with this build document.

IMPORTANT NOTE

Summary of Contents for ASTERIA MK. III

Page 1: ...w volumes Overdrive Amp Emulation 1 0 1 2020 12 10 Actual size is 2 3 x 1 86 main board and 1 78 x 0 87 bypass board BUILD DIFFICULTY Intermediate This documentation is for the Mk III version of the project There is also a Mk I version based on the Formula No 5 V1 and a Mk II version based on the Formula No 5 V2 While the names are similar the circuit and part numbering are different Please be sur...

Page 2: ...it s best placed after other drive pedals but before modulation However it also generates more than enough drive on its own and can be used as a standalone overdrive pedal just like any other The Formula 55 was preceded by two versions of the Formula No 5 in 2010 and 2011 These are available from Aion FX as the Asteria Mk I and Asteria Mk II The original Formula 55 used MPF4393 JFETs which are no ...

Page 3: ...esistor 1 4W R9 1M Metal film resistor 1 4W R10 68k Metal film resistor 1 4W R11 10k Metal film resistor 1 4W R12 5k1 Metal film resistor 1 4W R13 3k9 Metal film resistor 1 4W R14 1k Metal film resistor 1 4W R15 1M Metal film resistor 1 4W R16 1M Metal film resistor 1 4W R17 100R Metal film resistor 1 4W R18 1M Metal film resistor 1 4W R19 5k6 Metal film resistor 1 4W R20 15k Metal film resistor 1...

Page 4: ...notes Q2 MMBF4393 JFET N channel SOT 23 Substitute for MPF4393 TO 92 See build notes Q3 MMBF4393 JFET N channel SOT 23 Substitute for MPF4393 TO 92 See build notes Q4 MMBF4393 JFET N channel SOT 23 Substitute for MPF4393 TO 92 See build notes Q5 MMBF4393 JFET N channel SOT 23 Substitute for MPF4393 TO 92 See build notes VOL 1MA 16mm right angle PCB mount pot TONE 1MA 16mm right angle PCB mount pot...

Page 5: ...ntity of through hole MPF4393 and should be able to provide them in hobbyist quantities for the foreseeable future They are available in sets of 5 They are manufactured by ON Semiconductor the same as those used in the original Catalinbread pedal They test in the same range and will perform identically Setting bias trimmers TR1 and TR2 Trimmers TR1 and TR2 allow adjustment of the gain of the two m...

Page 6: ...1M 1M MPF4393 VA GND VA 10k 10k GND 22uF 5k1 3k9 GND GND 22n 3n3 GND GND 100R 100n MPF4393 1M 5k6 15k 100R GND GND 10k 10k VB 47uF GND GND VB VA 2u2 100R IN OUT R1 D1 C14 1 2 3 PRESENCE MASTER 1 2 3 C15 C1 R2 Q1 R3 TR1 1 2 3 C2 R4 R5 HI LO A2 A3 A1 HI LO B2 B3 B1 R6 C3 R7 R8 Q2 C4 TONE 1 2 3 1 2 3 VOLUME C5 C6 R9 R10 Q3 R14 C8 R15 R16 Q4 R11 TR2 1 2 3 C7 R12 R13 C9 C10 R17 C11 Q5 R18 R19 R20 R21 R...

Page 7: ...me jacks like the Switchcraft 111X If you d rather use open frame jacks please refer to the Open Frame Jack Drill Template for the top side LED hole drill size assumes the use of a 5mm LED bezel available from several parts suppliers Adjust size accordingly if using something different such as a 3mm bezel a plastic bezel or just a plain LED 0 1 2 CM 0 1 INCH x 0 y 1 20 ø15 32 x 0 775 y 1 20 ø5 16 ...

Page 8: ...ASTERIA PREAMP DRIVE MK III 8 ENCLOSURE LAYOUT Enclosure is shown without jacks See next page for jack layout and wiring 125B ...

Page 9: ...ASTERIA PREAMP DRIVE MK III 9 WIRING DIAGRAM 125B IN V GND N C N C OUT PCB IN GND V V JACK GND JACK OUT IN GND GND PCB OUT ...

Page 10: ...s of others Projects may be used for commercial endeavors in any quantity unless specifically noted No attribution is necessary though a link back is always greatly appreciated The only usage restrictions are that 1 you cannot resell the PCB as part of a kit without prior arrangement and 2 you cannot goop the circuit scratch off the screenprint or otherwise obfuscate the circuit to disguise its so...

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