Akashic Guitar effects PCB lookup
DRIVEBASSTREBLELEVELCLIPPING

125B · 5 knobs

Aion FX

TerminaTransparent Drive

Based on the Timmy V2

Category
Overdrive
Controls
Drive · Bass · Treble · Level · Clipping
Difficulty
Beginner
Price
$12.50in stock

From the vendor

The original transparent overdrive, designed to bring out the best in the guitar and amplifier. Includes a 2-band tonestack for bass and treble control.

The Termina Transparent Drive is based on the Timmy overdrive pedal from Paul Cochrane, with some modifications adapted from the Vemuram Jan Ray.

The Timmy was originally released in 2004 and is generally credited for kicking off the “transparent overdrive” genre of pedals. It does have a two-band tone control, but generally speaking it’s not designed to have much character of its own, instead bringing out the best qualities of the guitar and amplifier. While it has some similarities to a stripped-down Tube Screamer, there is no trace of the 720Hz mid-hump the Tube Screamer is known for.

The Termina is more specifically based on the Timmy V2 with the clipping diode switch, which is the same version that was licensed to MXR for their Custom Shop mini version. The Timmy V3 “15th Anniversary” edition was released in 2019, moving the diode selector inside the pedal and repurposing the toggle switch as a gain boost.

The Timmy has undergone several circuit changes throughout its run, so there is no single definitive schematic. This excellent research article from ManticoreFX tracks all the known differences, with several collected posts from Paul explaining the changes. The Termina project incorporates all of the revisions prior to the V3 overhaul, while reversing the travel of the bass and treble knobs so they increase the frequencies as they’re turned up instead of cutting as on the V2.

Please see page 10 of the build document for revised licensing terms which are different from our normal projects. The original Timmy pedal remains one of the best deals in the industry and we want to encourage as many people as possible to buy the original if they are able.

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 45 rows

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RefValueNormalizedTypeNotes
Resistors 13
R1510k510kMetal film resistor, 1/4WJan Ray uses 1M.
R23k33.3kMetal film resistor, 1/4WSome Jan Ray units use 33k.
R39k19.1kMetal film resistor, 1/4WUse 3k3 if omitting the bass trimmer mod.
R4680R680Metal film resistor, 1/4WPart of the bass trimmer mod. See build notes.
R51k1kMetal film resistor, 1/4WJan Ray uses 1k2.
R610k10kMetal film resistor, 1/4WJan Ray uses 3k3.
R710k10kMetal film resistor, 1/4WJan Ray uses 3k3.
R818k18kMetal film resistor, 1/4WOmit (leave empty) for Jan Ray.
R98k28.2kMetal film resistor, 1/4WJan Ray uses 9k1.
R1010k10kMetal film resistor, 1/4WJan Ray uses 7k5.
R11100R100Metal film resistor, 1/4W
RPD2M22.2MMetal film resistor, 1/4WInput pulldown resistor.
LEDR4k74.7kMetal film resistor, 1/4WLED current-limiting resistor. Adjust value to change LED brightness.
Capacitors 11
C139n39nFilm capacitor, 7.2 x 2.5mmJan Ray uses 47n.
C247pF47pMLCC capacitor, NP0/C0GJan Ray uses 22pF.
C3100pF100pMLCC capacitor, NP0/C0GJan Ray uses 47pF.
C439n39nFilm capacitor, 7.2 x 2.5mmSome Jan Ray units use 33n.
C51uF1uFilm capacitor, 7.2 x 3.5mm
C610n10nFilm capacitor, 7.2 x 2.5mmJan Ray uses 47n.
C72n22.2nFilm capacitor, 7.2 x 2.5mmJan Ray uses 150pF MLCC.
C81uF1uFilm capacitor, 7.2 x 3.5mm
C947uF47uElectrolytic capacitor, 5mmReference voltage filter capacitor.
C10100uF100uElectrolytic capacitor, 6.3mmPower supply filter capacitor.
C11100n100nMLCC capacitor, X7RPower supply filter capacitor.
Diodes 6
D11N58171N5817Schottky diode, DO-41
D21N9141N914Fast-switching diode, DO-35
D31N9141N914Fast-switching diode, DO-35
D41N9141N914Fast-switching diode, DO-35
D51N9141N914Fast-switching diode, DO-35
D61N9141N914Fast-switching diode, DO-35
ICs 1
IC1LM1458NLM1458NOperational amplifier, DIP8Can substitute JRC4559D (NJM4559D).
Potentiometers 4
GAIN1MAA1M16mm right-angle PCB mount potAudio (log) taper. Jan Ray uses 500kB.
BASS50kCC50k16mm right-angle PCB mount potReverse audio (reverse log) taper. Jan Ray uses 50kB.
TREBLE50kBB50k16mm right-angle PCB mount potLinear taper. Jan Ray uses 10kB.
VOLUME25kAA25k16mm right-angle PCB mount potAudio (log) taper. Jan Ray uses 10kB.
Trimmers 1
BASS TRIM10k10kTrimmer, 10%, 1/4”Part of the bass trimmer mod. See build notes.
Switches 2
CLIPSPDT cntr offSPDT CNTR OFFToggle switch, SPDT center off
FSW3PDT3PDTStomp switch, 3PDT
LEDs 1
LED5mm5MMLED, 5mm, red diffused
Jacks & sockets 4
IC1-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.