[review] Positive Grid BIAS Distortion - Tone Match Distortion Pedal (by LievenDV)

LievenDV sings and plays guitar in the Belgian band . He is a reverb nut and enjoys discovering innovating technology.

First impression

I bought the BIAS distortion a couple of months ago because this unit seemed to cover most of my overdrive and most of all: distortion needs.

Intrigued by the hardware+software combo that allows users to store more than enough presets in many different flavors of distortion, I decided to invest. The unit isn't cheap but this baby could replace my complete drive section. It isn't small either but way more handy than having a bunch of cables and pedals all wired together. The ability to edit the presets in an interface that didn't make me throw up was a refreshing experience for a change.

I found out that trying to copy/paste a whole bunch of pedals to a programmable distortion pedal is a cool concept but the platform is just as useful for people like me, who don't care about sounding like guitarist X or band Y. I want to build my own sounds and I'm glad I can.

Positive Grid BIAS DistortionThis is not your typical multi-effect pedal where you build a chain with a distortion, delay, reverb, chorus etc. from a list and you turn the knobs.

You only get to do the drive/distortion part but you can you in so much detail! Start from a preset and get to work in the different stages. You can add up to two EQ's between the stages you like to shape even more in-between. It's interesting to hear how rolling off or boosting frequencies makes the next stage respond completely different. The interface of the software is fun to work with and might seem a bit "fluffy" to hardcore techies but don't be fooled by looks; editing the chain will keep you tweaking that certain preset to what you like.

Nice touch, you can provide the face plate of your virtual pedal with custom artwork you can import.

The unit offers 2 banks with 10 presets each. Most of them have names on the physical unit but that doesn't matter, you can put anything you like in there.

You assign virtual pedals to the hardware pedal simply by a drag-and-drop in the software. On the hardware pedal you can easily decide which pedals you want under the 3 preset slots that can be accessed with the footswitches.

Sound quality and use

The overall quality is great and fiddling with the settings and internal EQ's isn't just a novelty. This unit delivers usable sounds, subtle light drives, crunchy rock n' roll, 90's alt-rock chops, high-octane heavy metal, gloomy darker shades of metal. You might think you are limited because this unit does only drive/dist but it actually made me tweak and think about my sounds more.

It takes some testing to get your settings on an even volume though. You can eliminate the need of a clean boost if you set certain pedals louder or quieter but because of the various output volume settings in the online presets, you need to test switching through the presets you use.Positive Grid BIAS Distortion

Putting all output knobs on 10 on all your pedals won't result in an even output volume.

There's also a booster (in 3 styles) on board of the hardware unit that can be put in front or in the back of the chain. It's handy but a bit extra volume from the booster would have been nice.

Online real-time examples.

The BIAS Distortion already has a nice set of user presets to pick from. Some people created their own artwork and thought of clever names, which only helps in marketing your own preset. What impressed me most though was the real-time example function. With your guitar and amplifier attached, you can immediately play through the pedal that is selected in the preset library. No more "how will it sound with my guitar and amp?".

Found a pedal but got that "close but no cigar" feeling? Save it anyway and start tweaking. You might end with a result completely different but that's the fun of it.


This BIAS pedal wants to distinguish itself by the ability to "profile" your sound. If you know how a Kemper profiler amp works, you know that software can learn the character of your sound and replicate it. This pedal does that as well but it needs a bit of setup you need to have a separate audio interface to get to work because the unit is not an interface on its own. Positive Grid BIAS DistortionThe profiling process itself is pretty very easy. After picking a pedal that is somewhat similar to the one you try to profile, a step-by-step process makes you play your clean and distorted sound and the software learns the difference between the two. I still don't get the hang of it to get that sound -just- right. I'm sure my untrained ear has much to do with that.

Options enough to tweak though.

Some details to fix

The power input isn't your regular "negative center barrel" plug. It's nice of them to ship a little converter but it is big and it makes the power plug a bit clunky, with a higher risk factor. The other thing is the connection of the software with the hardware. A couple of software updates later during the last 8 months made it go better but the connection isn't 100% stable yet on my Windows 10 machine. The USB cable could have been a tad longer so you have enough room to set up your pedal board next to your computer instead of taking the pedal out of your chain every time because you need to connect. No biggie, as you can buy that sort of stuff. The earlier mentioned volume issue isn't a showstopper either but I've still have some presets in my units that don't match in volume :).


You'll love it because this platform serves copycats, creative tweakers and everything in between. The real-time online examples make browsing for a base tone more fun than downloading 40 presets to delete them all afterwards. The profiling process itself is easy but you need a decent setup. This unit is a resident on my pedalboard as it is the core to my current guitar sound in my band…because I designed that sound myself!

Subscribe to our newsletter

Also check out Effects Database's social media accounts: