Fulltone OCD vs BOSS Blues Driver
A genuinely useful comparison, because the two pedals sit at opposite ends of the question every drive purchase turns on: how much should the pedal impose?
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We have not played this gear. Every pick below is chosen from published manufacturer specifications and the arithmetic set out in how we research, which you can re-run yourself.
The Blues Driver stays flat and gets out of the way — buy it when you like your amp's clean tone and want it roughened. The OCD imposes a character and crosses into distortion past about halfway — buy it when your amp stays clean and you need the pedal to be the sound. They are not competing for the same job, which is why so many boards end up with both.
This pairing comes up constantly on shortlists and the two pedals are more different than the shared "overdrive" label suggests. One is a modifier; the other is a source.
How much should the pedal impose?
| # | Product | Best for | Price |
|---|---|---|---|
| 01 | No photo BOSS BD-2 Blues Driver Flat through the mids, open at the top, and the most dynamic of the two by a clear margin. | Roughening an amp you already like | |
| 02 | No photo Fulltone OCD Obsessive Compulsive Drive Two selectable gain and EQ characters, and it crosses into distortion past about halfway. | An amp that stays clean and needs a voice |
Rows link to the full write-up further down this page. Prices come from the live price layer only — where there is no live figure the button reads “Check price” rather than showing a remembered number.
02The structural difference
The BD-2 gets its gain from discrete stages. There is no diode clipping stage inside an op-amp feedback loop shaping the EQ on the way through, so the frequency response stays broadly flat and a great deal of dynamic range survives.
The OCD's HP/LP switch changes the circuit's gain structure and low-mid emphasis together rather than applying an EQ at the output. That is why it reads as two different amps rather than two settings, and why the character persists across the whole gain range instead of only appearing when you turn it up.
| BOSS BD-2 | Fulltone OCD | |
|---|---|---|
| Gain structure | Discrete gain stages | Amp-voiced circuit with two switchable characters |
| Maximum gain | Light to moderate crunch | High — distortion territory past halfway |
| Mid response | Flat | Shifted by the HP/LP switch |
| Response to picking | High | Moderate |
| Cleans up on guitar volume | Yes, substantially | Less so |
| Into a clean amp | Subtle — you may want more | Full-range and usable as the only dirt |
| Into a driven amp | Adds grit without reshaping | Can get woolly — gain on gain |
| Published electrical data | Impedance, draw, dimensions, weight | None |
BOSS BD-2 Blues Driver
Roughening an amp you already like
The number1 M ohm in, 1 k ohm out, 20 mA — all published by BOSS.
The Blues Driver's gain comes from discrete stages rather than from diodes clipping inside an op-amp's feedback loop. That keeps the frequency response flat and the dynamic range wide, which is why it responds to picking strength and cleans up genuinely — not just quietly — when you roll the guitar volume back.
It is the right pedal when the amp is doing the work and you want a little more grit on top without changing what the amp sounds like.
The cons: it does not have a heavy setting. Past about two o'clock on the Gain it is still recognisably a light overdrive, and if you were hoping it would eventually become a distortion it will not. No adaptor included, and it is buffered rather than true bypass.
| Controls | Gain, Tone, Level, pedal switch |
|---|---|
| Input impedance | 1 M ohm |
| Output impedance | 1 k ohm |
| Current draw | 20 mA |
| Power | 9 V battery (6F22 / 6LR61) or PSA-series adaptor |
| Size / weight | 73 x 129 x 59 mm, 360 g |
| What it does not do | No adaptor in the box, no true bypass, and no mid control. The BD-2 is deliberately flat through the mids — if you want a mid hump to push a solo, this is the wrong pedal. |
Specs from BOSS BD-2 specifications. We have not used this unit.
Fulltone OCD Obsessive Compulsive Drive
An amp that stays clean and needs a voice
The OCD supplies its own character rather than amplifying the amp's. The HP/LP toggle changes gain and low-mid emphasis together — LP with less low-mid content and lower gain for a bright amp, HP with more of both for a darker one — so it is closer to two pedals than to one pedal with an EQ switch.
Into a clean solid-state amp it produces a full-range distorted tone on its own, which the Blues Driver cannot do. That is the single clearest reason to choose it.
The cons: past about two o'clock on the Drive it behaves like a distortion rather than an overdrive, so if you wanted a subtle push the top half of the knob is not it. It does not clean up on the volume knob the way the BD-2 does, and Fulltone publishes no electrical figures at all, so you cannot plan a shared supply around it without measuring.
| Controls | Volume, Drive, Tone, HP/LP toggle |
|---|---|
| HP/LP switch | Two voicings: LP with less low-mid emphasis, HP with more gain and upper-mid push |
| Power | 9 V DC center-negative; Fulltone documents internal operation at a higher rail |
| Electrical data | No current-draw or impedance figure is published for this pedal, so none is stated here. |
| What it does not do | No power supply included. It is not a subtle pedal at high Drive — past about two o'clock it behaves more like a distortion than an overdrive, and it will not clean up the way a Tube Screamer does. |
Specs from Fulltone OCD product page. We have not used this unit.
03Who each one is wrong for
- The BD-2 is wrong if you wanted the pedal to supply a heavy distorted tone. It has no such setting.
- The BD-2 is wrong as a lead boost in a band, because flat is the opposite of what cutting through a mix needs.
- The OCD is wrong if you wanted a low-gain transparent drive. Even in LP mode it has more character and more gain than that description implies.
- The OCD is wrong in front of an already-high-gain amp channel, where it compounds rather than tightens.
- Both are wrong if the amp itself is the problem. Pedal or amp is the page for that question.
04Running both
BD-2 into OCD is the order that works. The Blues Driver adds a full-range dirty signal and a level lift into the OCD's higher-gain stage, which pushes it without imposing a second tone stack. The reverse gives the BD-2 an already-distorted, already-compressed signal and mostly just adds volume.
If you own one and are considering the other, the honest question is which half of the job is missing. If your amp sounds good and the pedal just needs to add grit, you want the BD-2. If your amp is a clean platform and the pedal has to be the whole tone, you want the OCD. Best overdrive pedals covers the four circuit families this sits inside.
Frequently asked questions
+ Is the OCD an overdrive or a distortion?
+ Which is better for a clean amp?
+ Which cleans up better on the guitar volume knob?
+ What does the OCD's HP/LP switch do?
Sources
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