SUPER
Yellow
Asymmetric overdriveBoss SD-1 Super OverDrive · Pedal Zines № 11
Issue11
SD-1 (n.) Boss's yellow Super OverDrive: a Tube Screamer-style circuit with asymmetric clipping, three knobs and one big rubber stomp.
§ 01 · What it isRead me first
LEVEL = how loud, TONE = how bright, DRIVE = how much dirt. Stomp the pad; the red CHECK LED says it's on.
Drive low, level up
§ 02Where everything lives
The Map
Classic Boss compact layout: three same-size black knobs in a row (LEVEL, TONE, DRIVE, left to right), the CHECK LED, and a footswitch pad that's half the pedal.
Drawn from the SD-1 layout · knob pointers are decoration
- 1LEVELOutput volume when on. Match bypass, or crank it to slam the next pedal.
- 2TONEBrightness. Clockwise = more highs, counterclockwise = darker.
- 3DRIVEHow much dirt. Low = a warm nudge, high = thick, compressed overdrive.
- 4CHECK LEDLights red when the effect is on; also your battery check (dim or dark = swap it).
- 5Footswitch padThe big black rubber pedal. On/off via Boss's FET (electronic) switching. Thumbscrew under it opens the battery door.
- 6JacksInput on the right side, output on the left. Plugging into INPUT turns on battery power.
- 7AC adaptorRear jack: 9 V DC, center negative (Boss PSA-type adaptor).
✓ First sessionTap each one when done · saves on this device
First Session
0 / 5 done
YELLOW LIGHT.
- Power: 9 V DC, center negativeOr a fresh 9 V battery
- Guitar into the right jackAmp side out of the left
- Drive low, Level up to match bypassSame volume on and off
- Sweep TONE from 9 to 3Find where it stops sounding muddy or harsh
- Now roll DRIVE up slowlyHear the asymmetric clipping bite
§ 03For my chain
Quick Recipes
Clock positions, not factory presets. Set it, play, then nudge by ear.
Into the RAT
RAT PUSHER
- LEVEL: 2 to 3 o'clock
- TONE: noon
- DRIVE: 8 to 9 o'clock
Mostly volume and mids into the RAT: tighter, louder distortion. Starting point only.
Stack
STACKED CRUNCH
- NotaKlon: low gain, a bit of volume
- SD-1 LEVEL: noon (match bypass)
- SD-1 TONE: noon · DRIVE: 11 o'clock
The NotaKlon fattens the input; keep the SD-1's DRIVE modest so it doesn't get mushy.
Lead
WET LEAD
- LEVEL: a hair above bypass
- TONE: 1 o'clock
- DRIVE: 2 o'clock
Sustain for Phase 90 swirl, Caverns delay/reverb and the IR-2. Roll TONE back if it fizzes.
§ 04From the owner's manual
Power & Specs
POWER
- 9 V battery or AC adaptor (9 V DC, center negative).
- Current draw: 4 mA at 9 V (manual). Tiny.
- Unplug the input cable when done to save the battery.
THE BOX
- Controls: LEVEL · TONE · OVER DRIVE, FET switching, CHECK lamp.
- Input impedance 470 kΩ; output load impedance over 10 kΩ.
- 70 × 55 × 125 mm (W×H×D), 400 g.
§ 05Slot two on the board
In My Rig
The SD-1 sits second, right after the NotaKlon and in front of the RAT, so it can be a drive on its own or a boost for either neighbor.
NotaKlonklon-ish driveSD-1you are hereRATdistortionPhase 90phaserCavernsdelay + reverbIR-2amp/cab IR
§ 06Pedal trivia
Fun Facts
- Born 1981Boss released the SD-1 in 1981, and it has stayed in the lineup ever since.
- Asymmetric clippingThe big difference from a Tube Screamer: the clipping diodes are uneven (two one way, one the other), so the waveform clips differently on each half.
- TS cousinThe core is a Tube Screamer-style op-amp overdrive, so it shares the same mid-forward voice as the TS9 on my windowsill.
- Compact classicSame Boss compact shell as the rest of the family: the whole lower half is the footswitch, and you flip it up to change the battery.
- Sibling: OD-1Its predecessor, the OD-1 OverDrive (1977), had no tone knob. The SD-1 added TONE.
- Electronic switchingNo clicky mechanical bypass: Boss used FET switching, as the manual's spec page notes.
§ 07When in doubt