The Wampler TCD Drive, also called The Compulsion Drive, is an overdrive/distortion pedal from Wampler, designed by Brian Wampler as his take on the Fulltone OCD circuit12. Where the original OCD keeps its controls to volume, drive and tone, the TCD expands the circuit with a three-band EQ, two playback modes and two internal dip-switches, giving four circuit configurations in one pedal12.
Wampler announced the pedal in late November 2025, and by December 2025 it was available from the Wampler webstore12. Delicious Audio described it as "a meticulously engineered homage to a modern classic: the legendary Fulltone OCD"3.
The controls: three-band EQ, Gain, Level and Mode
The front panel carries six controls: Bass, Mids, Treble, Level, Mode and Gain1. Gearnews describes the EQ section as a typical three-band setup alongside Level and Gain2. The three-band EQ is the biggest departure from the OCD it is based on, since the Fulltone OCD V2 offers only volume, drive and tone controls4.
| Control | What it does |
|---|---|
| Gain | Sets the amount of drive12 |
| Level | Sets the output volume12 |
| Bass | Low-end EQ12 |
| Mids | Midrange EQ12 |
| Treble | High-end EQ12 |
| Mode | Selects Cascaded MOSFET or Stock1 |
The Mode switch is the other main front-panel feature. In the down position it gives the Stock, or Traditional, circuit character; in the up position it engages cascaded MOSFET gain stages, which Wampler states give a "harder-hitting and more tube-like sound"2. Delicious Audio frames the two settings as "two distinct gain personalities: the traditional circuit character or a more aggressive, cascaded MOSFET voicing for a harder-hitting, tube-like saturation"3.
Internal Diode and Fat dip-switches
Inside the pedal are two internal dip-switches, labeled Diode and Fat, each with Off/On positions1. These are not front-panel controls, so changing them means opening the enclosure.
- Diode (Off/On): selects between clipping diode configurations in the circuit1
- Fat (Off/On): adds more fatness to the output; Delicious Audio says the Fat switch "adds foundational low-end warmth"13
Gearnews sums up the appeal of this arrangement: the internal DIP switches "allow 4 classic circuit variations in one pedal"2. Combined with the two Mode settings, a player gets several flavors of OCD-style drive without buying multiple pedals.
History: Brian Wampler's take on the OCD
The TCD is Brian Wampler's take on the Fulltone OCD, a circuit he has expanded rather than copied12. Guitar Pedal X puts it directly: "Brian Wampler's TCD Drive expands the OCD circuit," souping it up with the 3-band EQ, the two main playback modes and the internal dip-switches1.
The OCD circuit has also drawn the attention of other builders. Brian Wampler's TCD Drive is an overdrive that expands the OCD circuit1. Wampler builds it in an enclosure with top-mounted jacks2. One reviewer wrote of the TCD Drive, "It sounds very impressive in the demos, while Brian is in such high esteem with me - that I ordered said pedal well befo"1.
Guitar Pedal X's reviewer, Stefan Karlsson, reports that the TCD "retains the OCD's Marshally Crunch" while adding saturation and output fatness, and that it "sounds very impressive in the demos." He adds that he ordered the pedal before watching any demos, on the strength of his regard for Brian Wampler's work1.
"It sounds very impressive in the demos, while Brian is in such high esteem with me - that I ordered said pedal well before I got anywhere near the demos."
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Questions
What is the difference between the Wampler TCD and a Fulltone OCD?
The TCD is built on the Fulltone OCD circuit but adds a three-band EQ (Bass, Mids, Treble) where the OCD V2 has volume, drive and tone, plus a Mode switch with Stock and Cascaded MOSFET settings, and internal Diode and Fat dip-switches. Together the modes and dip-switches give four circuit variations in one pedal.
What does the Cascaded MOSFET mode on the Wampler TCD do?
The Mode switch selects between Stock, the traditional circuit character, and Cascaded MOSFET, which Wampler describes as harder-hitting and more tube-like. Delicious Audio calls it a more aggressive, cascaded MOSFET voicing for harder-hitting, tube-like saturation, so it is the amp-like high-gain option of the two.
How much does the Wampler TCD Drive cost?
Guitar Pedal X reported the TCD at $199 from the Wampler webstore in December 2025, while Gearnews listed it at Thomann for $213 / £195 / €219 in November 2025.
Where are the dip-switches on the Wampler TCD?
The Diode and Fat dip-switches are inside the pedal, not on the front panel. You have to open the enclosure to reach them. Diode is Off/On and Fat is Off/On, with the Fat switch adding foundational low-end warmth to the output.
Sources (4)
- Guitar Pedal X, Guitar Pedal X, 2025-12-01
- Wampler TCD: The Compulsion Drive with 4 Circuits, gearnews.com, 2025-11-28
- New Pedal: Wampler TCD Drive, Delicious Audio, 2025-12-01
- Review: Fulltone OCD V2 Overdrive Pedal, Guitar World, 2017-09-15
