The Mosky Obsessive Overdrive is a mini overdrive pedal from Mosky, product model MP-33, built as a compact take on the Fulltone OCD circuit. Mosky describes it plainly: "Based on Fulltone OCD"1. It comes in a white enclosure measuring 92mm x 38mm x 36mm (W/D/H) and weighing 125g, small enough to sit in a tight spot on a pedalboard1.
Delicious Audio's write-up framed it exactly that way, calling it "a lot smaller and a lot cheaper than the original" OCD2. For a player who wants the OCD's control layout and voicing switch without the full-size enclosure, this is the pedal built for that job.
The controls and the HP/LP switch
The control set is the classic OCD layout: three knobs and a voicing switch12.
| Control | What it does |
|---|---|
| Drive | Sets the gain amount1 |
| Volume | Sets the output volume1 |
| Tone | Sets the tonal balance1 |
| HP/LP switch | Chooses between High Peak and Low Peak voicings1 |
Mosky calls the three knobs "pretty standard fare on most overdrives," letting you dial in the gain, adjust the output volume, and find the tonal balance1.
The HP/LP switch is where the OCD-style design shows through. Mosky describes the two modes123:
- HP (High Peak): increased distortion and low end, thickening up your sound for a more "British" flavor1
- LP (Low Peak): a more accurate rendition of your sound with very little coloration of your tone1
In practice, HP is the setting for a thicker, more aggressive drive with extra low-end weight, while LP keeps the pedal closer to transparent, letting more of your amp and guitar's own character through. The switch itself is a simple circuit trick inherited from the original design: on the Fulltone OCD v4, Pedal of the Day's reviewer explained that "all the switch does is add a resistor parallel making more signal pass through"3. That same reviewer noted of the original that "the LP can get muddy compared to the HP," a useful warning for anyone living on the LP setting3.
The HP/LP switch changes the pedal's voicing, not its gain range. Both settings use the same Drive knob; HP simply pushes more low end and distortion into the signal.
Power and bypass
Mosky lists the pedal as true bypass, so the signal passes through untouched when the pedal is switched off1. Delicious Audio's page lists the same feature2.
On power, the pedal runs on a DC power supply, and Mosky says using a higher-voltage supply gives the pedal more headroom1. More headroom means the pedal stays cleaner at higher volume settings before the circuit itself starts to break up, which suits players using it as a light-drive or boost stage. Delicious Audio repeats the same power spec2.
Mosky's spec calls for a DC power supply, and the maker says a higher-voltage supply increases headroom. Feeding the pedal the wrong polarity, or a voltage outside what the maker's spec covers, is not covered by the maker's spec.
How it fits with other Mosky overdrives
Mosky builds a range of mini overdrives, each based on a different well-known circuit. The Obsessive Overdrive is the OCD-style entry, sitting alongside the MOSKY Golden Horse, the MOSKY Green Drive Overdrive, the Mosky Mini Screamer Overdrive, and the Mosky Hand-Wired Ultimate Drive in the maker's mini pedal line1. A player comparing compact overdrives can pair the Obsessive with one of the others for two distinct gain voices on a small board.
Videos
Doctor McFarland Studios
Budget Pedal Chap
Chuck Music and Effects
Questions
Can the Mosky Obsessive Overdrive run on 18 volts?
Yes. Mosky says it runs on a standard 9-volt adapter, and that plugging in an 18-volt power supply gives even more headroom. So a player who wants more clean volume before the pedal breaks up can feed it 18V instead of 9V.
Is the Mosky Obsessive Overdrive true bypass?
Yes. Mosky lists true bypass switching for the Obsessive Overdrive, so when the pedal is off the guitar signal passes through without the circuit coloring it. Delicious Audio's write-up of the pedal lists the same feature.
What is the difference between HP and LP on the Mosky Obsessive Overdrive?
HP is High Peak and LP is Low Peak. Mosky says HP gives increased distortion and more low end for a thicker, more British flavor, while LP gives a more accurate rendition of your sound with very little coloration. HP is the thicker, more aggressive setting.
Sources (3)
- Obsessive Overdrive_Mini Guitar Pedals_Effect Pedals_Products_mosky pedal, moskyaudio.com
- Mosky Audio Obsessive Drive, Delicious Audio, 2021-03-01
- Fulltone OCD Overdrive V4, Pedal of the Day, 2015-05-30
