Akashic Guitar effects circuit lookup
EXPANDEROCTAVETONEBALANCE

125B · 4 knobs

Naegele Audio

The Ocelot

Based on the Univox Super-Fuzz· 37 other boards clone it

Want a PCB? Naegele Audio laid out a PCB for this circuit and sells boards, as well as relay bypass and I/O boards: message PedalBuilder on the PedalPCB forum.

Category
Fuzz
Controls
Expander · Octave · Tone · Balance
Price
see vendor
Tags
PedalPCB forum, PCB by message
Read the post at Naegele Audio

From the vendor

Here's my take on the Univox Super Fuzz. I was going for something a bit different and more flexible than the original, so I borrowed some features from the now discontinued Wattson Classic Electronics EFY-6 . The main changes are adding an octave control that goes from no octave up to full octave up, replacing the tone switch with a potentiometer, and changing the bias resistors on the output stage to increase the output level above unity. I've included the schematic at the bottom of the post for anyone who's curious. If I was redoing the board, I'd try to add some more room between the rows of 10µF capacitors and the solder pads for the Octave and Tone pots. I was able to solder everything without hitting the capacitors with the iron, but it was more of a challenge than I would have liked. For the tone knob modification, I recommend using a B50k potentiometer, as there is a noticeable volume drop in the middle of the rotation when using a B100k. Using a potentiometer rather than a switch slightly reduces the depth of the mid-scoop and height of the mid-hump, and adds some great sounding in-between tones. For the octave knob, I tried 10k and 5k potentiometers. The most dramatic change to the octave effect happens in the first 1kΩ of resistance; by about 4kΩ the octave effect is essentially gone. As a result, I went with a C5k to maximize the control over the octave intensity. The Super Fuzz works best with transistors with an hFE between 110 and 140. Using higher gain transistors results in a mushy, less bassy tone, and lower gain transistors sound weak and (unpleasantly) gated. I used 2N5551 transistors from Tayda , which are dirt cheap and have gains between 120 and 135. For Q4 and Q5, I used a pair with identical hFE and V BE values to maximize the intensity of the octave up. When I breadboarded the circuit, I originally tried germanium diodes, but on a whim I tried some 1N60P Schottky diodes that I bought from Tayda 12 years ago but had never gotten around to using. Compared to the germanium diodes, the Schottky diodes sounded more compressed and distorted, probably due to their lower Vf (0.22v at 1mA vs 0.33v at 1mA for the germanium diodes), and the octave overtones were slightly more pronounced. I preferred the sound of the Schottky diodes, so I kept them in the final build. The enclosure is a white 125B from Tayda, UV printed with a gloss varnish. <a href="https://forum.pedalpcb.com/attachments/img_2777-jpeg.77966/" target="_blank"> <img src="data:image/svg+xml;charset=utf-8,%3Csvg xmlns%3D'http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg' width='1511' height='2000' viewBox%3D'0 0 1511 2000'%2F%3E" data-src="https://pedalpcb-forum.nyc3.digitaloceanspaces.com/data/attachments/77/77985-3e83a5b76a502c549f7825c4216b0ee6.jpg?hash=PoOlt2pQLF" class="bbImage lazyload" style="" alt="IMG_2777.jpeg" title="IMG_2777.jpeg" width="150" height="199" /> <img src="https://pedalpcb-forum.nyc3.digitaloceanspaces.com/data/attachments/77/77985-3e83a5b76a502c549f7825c42

Schematic

The schematic is in the post. Open it at Naegele Audio. No KiCad fragment has been drawn for this circuit yet.

Parts list 61 rows

Report a wrong parse

Got parts in a drawer? See what you can build with them.

RefValueNormalizedTypeNotes
Resistors 31
R122k22kread from the schematic by eye
R2100k100kread from the schematic by eye
R347k47kread from the schematic by eye
R41.8k1.8kread from the schematic by eye
R5100k100kread from the schematic by eye
R6470k470kread from the schematic by eye
R710k10kread from the schematic by eye
R847k47kread from the schematic by eye
R910k10kread from the schematic by eye
R10220k220kread from the schematic by eye
R11150k150kread from the schematic by eye
R1210k10kread from the schematic by eye
R1310k10kread from the schematic by eye
R14470R470read from the schematic by eye
R15470R470read from the schematic by eye
R16100k100kread from the schematic by eye
R1720k20kread from the schematic by eye
R1810k10kread from the schematic by eye
R191.8k1.8kread from the schematic by eye
R20100k100kread from the schematic by eye
R2120k20kread from the schematic by eye
R2247k47kread from the schematic by eye
R2310k10kread from the schematic by eye
R2422k22kread from the schematic by eye
R2510k10kread from the schematic by eye
R2624k24kread from the schematic by eye
R271.2k1.2kread from the schematic by eye
R28750k750kread from the schematic by eye
R2975k75kread from the schematic by eye
R30100k100kread from the schematic by eye
R10124k24kLED current limiting resistor; read from the schematic by eye
Capacitors 16
C110u10uread from the schematic by eye
C21n1nread from the schematic by eye
C3100n100nread from the schematic by eye
C410u10uread from the schematic by eye
C510u10uread from the schematic by eye
C610u10uread from the schematic by eye
C710u10uread from the schematic by eye
C810u10uread from the schematic by eye
C910u10uread from the schematic by eye
C1010u10uread from the schematic by eye
C1110u10uread from the schematic by eye
C121n1nread from the schematic by eye
C13100n100nread from the schematic by eye
C1410u10uread from the schematic by eye
C1510u10uread from the schematic by eye
C10210u10usupply filter; read from the schematic by eye
Diodes 2
D11N60P1N60Pread from the schematic by eye
D21N60P1N60Pread from the schematic by eye
Transistors 6
Q12N55512N5551read from the schematic by eye
Q22N55512N5551read from the schematic by eye
Q32N55512N5551read from the schematic by eye
Q42N55512N5551read from the schematic by eye
Q52N55512N5551read from the schematic by eye
Q62N55512N5551read from the schematic by eye
Potentiometers 4
ExpanderA50kA50kPotentiometerread from the schematic by eye
OctaveC5kC5kPotentiometerread from the schematic by eye
ToneB50kB50kPotentiometerread from the schematic by eye
BalanceA50kA50kPotentiometerread from the schematic by eye
Trimmers 1
TRIM5k5kphase splitter balance; read from the schematic by eye
LEDs 1
LEDLEDLEDstatus LED; read from the schematic by eye

Other boards based on the Univox Super-Fuzz