The Fulltone Obsessive Compulsive Drive (OCD) is an extremely open sounding Overdrive/Distortion circuit that differs from other overdrives in that it has a good bit more Dynamic-Range, meaning the difference between picking soft or picking hard will actually yield a more natural and wider range of distortion, with less compression than traditional diode-clipped overdrives. The OCD also creates complex overtones without changing the inherent tone of the guitar & amps that you’re playing through, in the process lifting off that “muffled blanket” other drive pedals can put on your sound.
Fulltone CS OCD-GE Germanium Overdrive Pedal Features:
- An extremely open sounding Overdrive/Distortion circuit
- Less compression than traditional diode-clipped overdrives
- Tube-like distortion thanks to a combo of clipping techniques
- Germanium diodes replace JFET OpAmp for a unique, amp-like tone
- Germanium offers wider range for softer tones without losing hard clipping
- Try it at 18VDC for more headroom, dynamic range, & clarity
- Audio taper allows you to find the right volume without having to be super-careful
- Internally selectable True-Bypass or Enhanced Bypass
- HP/LP Switch for tonal versatility & added control
The OCD accomplishes its tube-like distortion through the unusual combination of overdriving its JFET opamp and additionally with the use of hard-clipping via a pair of MOSFETs to “Vref. This method did not exist in a pedal prior to the OCD, and you’ll find that this design works very well with a vast array of guitars and amps. Because of its large amount of available output volume, the OCD works great as a booster in front of amps to goose them into submission, as well as through Master-Volume amps to drive them much harder than most OD’s can, but it also excels at creating its own distortion. The OCD can give the impression that your amp is cranked at even living room volume, so clean playing is more dynamic and dirty sounds still have the ringing overtones. The OCD’s can access a slew of other in-between sounds by simply turning up or down your guitar’s volume control, in fact, no other pedal “cleans up” like the OCD.
Try it at 18VDC and you get another level of dynamic range and clarity. They recommend using the Fulltone IPS-18 for 18volt operation (for use in all countries) as it is regulated and quiet. Avoid using other “switching type” power supplies, as we get a lot of reports that the majority of them hiss, hum, and some even create strange synth-like noises. Theirs is quiet.
The Custom Shop OCD-Ge has some exciting differences from other OCD versions
Germanium Diodes: A pair of matched Germanium diodes are used in conjunction with the pair of Mosfets. This not only widens the clipping threshold, but the clipping takes on the “soft-knee” characteristics of the Germanium diodes, giving a tubey feel and enhancing Octave-up overtones.
Audio (Log) Taper Volume Pot: Earliest OCDs had an Audio taper volume pot which changes where (during the Volume knob’s rotation-sweep) the volume comes on. I went with an Audio taper on this one because the CS-OCD-Ge is a bit louder than regular OCDs, and the Audio taper allows you to find the right volume without having to be super-careful around the lower third section of the pot’s rotation.
A more open sound: The softer characteristics imparted by the Germanium diodes allowed me to tweak some values to let through more highs, this results in more clarity without harshness when the tone control is turned up.
Internally selectable True-Bypass or Enhanced Bypass™:
For many years the average guitarist’s rig consisted of only a few pedals, and True-Bypass (TB) switching was the ultimate way to achieve a clean signal path. Everything’s different now, most guitarists have elaborate pedalboards with 10 or more pedals being the norm! Once you have multiple jumper cables, multiple effects (even with true-bypass) pedals, there is tone loss and loss of dynamics, meaning the amp ceases to respond to differences in picking attack.
Worse, many tuners, loopers, and pedals employ poorly-designed buffered-bypass, while recouping some of the high-end signal, they still suffer from a complete loss of dynamics. Enter Enhanced BypassTM (EB), this exclusive Fulltone bypass system brings back all of the lost dynamics and tone that all those cables and other pedals take away. And EB offers totally “pop free” switching, so you don’t get any loud and possibly destructive noises when switching the pedal ON or OFF.
You can choose whether your OCD employs True-Bypass or Enhanced Bypass™ switching by opening up the pedal (removing all 4 thumbscrews and pulling the pedal enclosure apart) and sliding the Bypass switch up (for EB) or down for (TB), see photo to the right. Warning! make sure that the switch is set either full up or full down, and not in the middle, to avoid cutting out of the sound accompanied by a strange high-pitched noise.
Fulltone 3PDT footswitch: we use the best parts available anywhere, including the best switch in the world…the Fulltone-designed and manufactured 3PDT.
Drive Knob: Turn this Clockwise (CW) for more distortion, keep below 10 0‘clock for cleaner sounds and for boosting your amp’s input without changing your basic tone
Volume Knob: Controls the amount of signal that exits the pedal. The OCD has about 20dB of available gain (more in HP mode) so don’t be surprised if you end up running the Volume control at around 10 o’clock to get unity gain on lower gain settings.
HP/LP Switch: Set to HP (High Peak) you get increased distortion throughout the Drive Knob‘s range, more volume, and a slight increase in the midrange (between1-2 Khz) for more of a “British” vibe (ala Vox and Marshall). Set to LP (Low Peak) you get incredible accuracy to the original sound of your Guitar and amp…very little coloration! Excellent for Clean Boosting, for cranked Blackface or Tweed-style ones, and for when you’re not going for a British type sounds.
Tone Knob: This knob only affects the high frequencies, you’ll find that 12 o’clock position is very much neutral, turn it CCW (counter clockwise) to 10 o’clock or so for smoother high-gain lead sounds (with Drive knob higher than 12 o’clock) or turn it clockwise for more cut, and a less compressed feel.
Sample Settings:
- Blues/Rock Rhythm tones (Neck PU, on clean set amp):
- Volume: 11 o’clock
- Drive: 10 o’clock
- Tone: set to preference
- Toggle: LP
- Rock British Tones (Bridge PU on clean set amp):
- Volume: 10 o’clock
- Drive: 1 o’clock
- Tone: set to preference
- Toggle: HP
