Akashic Guitar effects PCB lookup
GAINBASSMASTERFEEDBACK

125B · 4 knobs

Aion FX

Apollo Mk. IPreamp Drive

Based on the Catalinbread WIIO· 2 other boards clone it

Category
Overdrive· Overdrive / Amp Emulation
Controls
Gain · Bass · Master · Feedback
Difficulty
Intermediate
Price
$12.50in stock

From the vendor

An adaptation of the Hiwatt amplifier used by Pete Townshend of The Who during their “Live at Leeds” performance from 1970.

The Apollo Preamp Drive Mk. I is an adaptation of the Catalinbread WIIO, based on the Hiwatt amplifiers used by Pete Townshend of The Who, particularly their Live at Leeds show from February 14, 1970. (The artwork for the original pedal makes it obvious that “WIIO” is intended to resemble “WHO”.)

The WIIO was originally released in 2009 as a limited run of 100. The limited availability caused a huge debacle as people from gear forums bought up all the preorders and flipped them for profit, capitalizing on Catalinbread’s favored status among gear aficionados.

Catalinbread was not happy with the way the circuit turned out, so before releasing the non-limited version, they overhauled the circuit to reduce the gain and tweak the EQ so it was more versatile as an amp platform. Most people agree that the second version is superior, but the hype surrounding the first version has given it a lasting reputation.

The WIIO was succeeded by the RAH, which is largely the same circuit but with a midrange knob added, and the circuit re-voiced for Led Zeppelin’s famous show at the Royal Albert Hall. (They even referred to the RAH as the “Royal Albert Hall Edition of the WIIO” in the manual.) The WIIO was discontinued shortly after the release of the RAH.

The Apollo Mk. I is a direct adaptation of the V2 WIIO (non-limited version). The only modification is the addition of a trimmer that makes a feedback resistor variable, allowing adjustments to the gain, tone and feel of the circuit. The RAH is also available as the Apollo Mk. II.

Important note: According to Catalinbread[1], the WIIO (and thus this pedal) should only be run at 9V. It should not be used with an 18V adapter or with the Aion FX 18V bypass PCB.

Notes & references • See this thread at TGP (erksin was their customer support lead and often responded on forums on behalf of the company) ↩

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 58 rows

Report a wrong parse
RefValueNormalizedTypeNotes
Resistors 22
R110M10MMetal film resistor, 1/4W
R23k33.3kMetal film resistor, 1/4W
R33k33.3kMetal film resistor, 1/4W
R41k1kMetal film resistor, 1/4W
R512k12kMetal film resistor, 1/4W
R610M10MMetal film resistor, 1/4W
R73k33.3kMetal film resistor, 1/4W
R83k33.3kMetal film resistor, 1/4W
R9100k100kMetal film resistor, 1/4W
R1010k10kMetal film resistor, 1/4W
R1110M10MMetal film resistor, 1/4W
R123k33.3kMetal film resistor, 1/4W
R133k33.3kMetal film resistor, 1/4W
R14130R130Metal film resistor, 1/4W
R1547k47kMetal film resistor, 1/4W
R1612k12kMetal film resistor, 1/4W
R1712k12kMetal film resistor, 1/4W
R1862k62kMetal film resistor, 1/4W
R1982k82kMetal film resistor, 1/4W
R20100R100Metal film resistor, 1/4W
RPD2M22.2MMetal film resistor, 1/4W
LEDR4k74.7kMetal film resistor, 1/4W
Capacitors 20
C1270pF270pMLCC capacitor, NP0/C0G
C2100n100nFilm capacitor, 7.2 x 2.5mm
C3100uF100uElectrolytic capacitor, 6.3mm
C4100n100nFilm capacitor, 7.2 x 2.5mm
C547n47nFilm capacitor, 7.2 x 2.5mm
C6100uF100uElectrolytic capacitor, 6.3mm
C74.7uF4.7uElectrolytic capacitor, 4mm
C84n74.7nFilm capacitor, 7.2 x 2.5mm
C910n10nFilm capacitor, 7.2 x 2.5mm
C1010n10nFilm capacitor, 7.2 x 2.5mm
C11470pF470pMLCC capacitor, NP0/C0G
C12100n100nFilm capacitor, 7.2 x 2.5mm
C13100uF100uElectrolytic capacitor, 6.3mm
C14470n470nFilm capacitor, 7.2 x 3mm
C1510uF10uElectrolytic capacitor, 5mm
C162n22.2nFilm capacitor, 7.2 x 2.5mm
C172n22.2nFilm capacitor, 7.2 x 2.5mm
C1847uF47uElectrolytic capacitor, 5mm
C19100uF100uElectrolytic capacitor, 6.3mm
C20100n100nMLCC capacitor, X7R
Diodes 4
D11N58171N5817Schottky diode, DO-41
Z11N4739A1N4739AZener diode, 9V, DO-41
Z21N4739A1N4739AZener diode, 9V, DO-41
Z31N4739A1N4739AZener diode, 9V, DO-41
Transistors 3
Q1BS170BS170MOSFET, N-channel, TO-92
Q2BS170BS170MOSFET, N-channel, TO-92
Q3BS170BS170MOSFET, N-channel, TO-92
Potentiometers 3
GAIN500kAA500k16mm right-angle PCB mount pot
BASS500kAA500k16mm right-angle PCB mount pot
MSTR.100kAA100k16mm right-angle PCB mount pot
Switches 1
FSW3PDT3PDTStomp switch, 3PDTAvailable from Aion FX.
Jacks & sockets 3
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 mountLumberg NEB/J 21 C or equivalent.
Hardware 1
ENC125B125BEnclosure, die-cast aluminumCan also use a Hammond 1590N1.
Other 1
FDBK.250k trimmer T250K TRIMMER Trimmer, 10%, 1/4"See build notes.

Other boards based on the Catalinbread WIIO