Akashic Guitar effects PCB lookup
BASSTREBLELEVEL

125B · 3 knobs

Aion FX

TesseractBoost / Preamp

Based on the TC Electronic Integrated Pre

Category
Boost· Boost / Preamp
Controls
Bass · Treble · Level
Difficulty
Intermediate
Price
$12.50in stock

From the vendor

A pedal adaptation of the legendary booster and tone shaper famously used by Meshuggah.

The Tesseract Boost/Preamp is an adaptation of the TC Electronic Integrated Preamp, a boost & EQ from the late 1970s. The Integrated Pre is so named because it’s designed to connect directly to your guitar, which is why the original unit did not have a bypass switch.

The Integrated Preamp gained fame as the secret behind Meshuggah’s guitar tone in the 1990s. The boost was perfect for pushing the front of their Mesa/Boogie Dual Rectifiers and the EQ can cut bass for a tighter driven tone.

The original unit could run on as much as 32V using an external supply, or it could operate at the standard 9V using a battery. Since 32V supplies are hard to come by, the Tesseract Boost/Preamp includes an on-board charge pump that quadruples the input voltage (minus a few diode drops), allowing a 32V operation from a standard 9V supply.

The only other modification is the removal of a pop-suppression circuit at the input. This is designed to prevent the loud pop when the input jack is first plugged in. It’s useful in the original unit that connected straight to the guitar since the preamp would reasonably be plugged & unplugged in a live setting. However, in pedal format, the suppression circuit has no function other than to increase the current consumption as it is always bleeding some of the supply voltage to ground. There is no impact to the tone or functionality if it’s omitted.

Note: This project uses a type of capacitor that has been temporarily discontinued by WIMA. Please see our news article about the issue and the substitution spreadsheet for project-specific recommendations. We are stocking a limited supply in the mean time. The build document has not yet been updated to reflect this.

Schematic

The schematic is in the vendor's build document, page 6. Open the build document. No KiCad fragment has been drawn for this circuit yet.

Parts list 54 rows

Report a wrong parse
RefValueNormalizedTypeNotes
Resistors 13
R14k74.7kMetal film resistor, 1/4W
R26M86.8MMetal film resistor, 1/4W
R3100k100kMetal film resistor, 1/4W
R4220k220kMetal film resistor, 1/4W
R5470R470Metal film resistor, 1/4W
R64k74.7kMetal film resistor, 1/4W
R78k28.2kMetal film resistor, 1/4W
R8220R220Metal film resistor, 1/4W
R910k10kMetal film resistor, 1/4W
R10100k100kMetal film resistor, 1/4W
R111M1MMetal film resistor, 1/4WR11 is shown as 820k in one of the two known factory schematics.
RPD2M22.2MMetal film resistor, 1/4WInput pulldown resistor.
LEDR4k74.7kMetal film resistor, 1/4WLED current-limiting resistor. Adjust value to change LED brightness.
Capacitors 19
C147n47nFilm capacitor, 7.2 x 2.5mm
C2100pF100pMLCC capacitor, NP0/C0G
C31uF1uFilm capacitor, 7.2 x 3.5mm
C44.7uF4.7uElectrolytic capacitor, 4mm
C54n74.7nFilm capacitor, 7.2 x 2.5mm
C647n47nFilm capacitor, 7.2 x 2.5mm
C722n22nFilm capacitor, 7.2 x 2.5mm
C8220n220nFilm capacitor, 7.2 x 2.5mm
C9100uF100uElectrolytic capacitor, 6.3mm
C10470n470nMLCC capacitor, X7R
C1110uF10uElectrolytic capacitor, 5mmMust be rated for at least 50V.
C1210uF10uElectrolytic capacitor, 5mmMust be rated for at least 50V.
C1310uF10uElectrolytic capacitor, 5mmMust be rated for at least 50V.
C1410uF10uElectrolytic capacitor, 5mmMust be rated for at least 50V.
C1510uF10uElectrolytic capacitor, 5mmMust be rated for at least 50V.
C1647uF47uElectrolytic capacitor, 6.3mmMust be rated for at least 50V.
C17470n470nMLCC capacitor, X7R
C1810uF10uElectrolytic capacitor, 5mmMust be rated for at least 50V.
C19100n100nMLCC capacitor, X7R
Diodes 8
D11N58171N5817Schottky diode, DO-41
D21N4742A1N4742AZener diode, 12V, DO-41
D31N58171N5817Schottky diode, DO-41
D41N58171N5817Schottky diode, DO-41
D51N58171N5817Schottky diode, DO-41
D61N58171N5817Schottky diode, DO-41
D71N58171N5817Schottky diode, DO-41
D81N58171N5817Schottky diode, DO-41
Transistors 1
Q12N50882N5088BJT transistor, NPN, TO-92Original uses BC548C, which will need to be rotated 180 degrees if used since the pinout is mirrored.
ICs 2
IC1LM741LM741Operational amplifier, DIP8Factory schematic also specifies TL071 and LF356, but all photos of real units show LM741.
IC2LT1054CPLT1054CPCharge pump, DIP8
Potentiometers 2
BASS50kCC50k16mm right-angle PCB mount pot
LEVEL50kAA50k16mm right-angle PCB mount pot
Switches 1
FSW3PDT3PDTStomp switch, 3PDT
LEDs 1
LED5mm5MMLED, 5mm, red diffused
Jacks & sockets 5
IC1-SDIP-8 socketDIP-8 SOCKETIC socket, DIP-8
IC2-SDIP-8 socketDIP-8 SOCKETIC socket, DIP-8
IN1/4" stereo1/4" STEREO1/4" phone jack, closed frameSwitchcraft 112BX or equivalent.
OUT1/4" mono1/4" MONO1/4" phone jack, closed frameSwitchcraft 111X or equivalent.
DC2.1mm2.1MMDC jack, 2.1mm panel mountMouser 163-4302-E or equivalent.
Hardware 2
BATTBattery snapBATTERY SNAP9V battery snapOptional. Use the soft plastic type—the hard-shell type will not fit.
ENC125B125BEnclosure, die-cast aluminumCan also use a Hammond 1590N1.