Positive Grid is a company whose BIAS mobile apps you may have used to dial up a tasty amp sim sound, right on your phone or tablet, or maybe on their desktop version. Or perhaps you’ve played one of their recent multi-pedals that have been released. But it might be that you’ve never plugged into one of their hardware BIAS amp modelers such as the BIAS rack. That was the case for me before they sent me one to review – I’d used their BIAS desktop plugin and BIAS FX plugin pretty extensively, but I’d never plugged into one of their physical products before.
PG’s first foray into hardware was the lunchbox version of this amp, simply called the BIAS Amp. I tend to think that lunchboxes like it and the Kemper are a tad awkward looking, and seem somehow fragile compared to a typical headshell amplifier sitting on top of a cab (although they weight significantly less). So I was excited when the BIAS Rack was introduced, a 2U rackmount version of the BIAS head, with all the same trimmings. Both include a 600w solid-state power amp, which eliminates an entire separate rackmount unit from your rig – that’s handy! The rack unit is quite light, easily carried in one hand, and won’t add much to your rack setup’s weight.
At first glance, the Rack looks much like the faceplate of any typical amplifier head. Some knobs and switches, an input jack, some LED lights. And if you never ventured beyond what you can dial in on the front panel, you’re still in pretty good shape – there’s a small galaxy of tone shaping options there alone. But venture to the connectivity of the amp, and there’s a multiverse of editing features available to you that will take you far beyond the typical control panel features. Using either the USB connection to your computer or the Bluetooth antenna, you can connect to the BIAS Amp standalone app on desktop or mobile and go inside the amp’s advanced features.
Inside the app, you can choose from a wide variety of amplifier types, and from there you can edit many of the different parts that make up an amplifier’s core sound. Tube types, transformers, bias (naturally), and a whole host of other small details that make up the big picture sound of your amp. And that’s before you even get to the cabs! Included are a ton of different cab types, along with 2 different mics that you can position however you like in a room space. The sheer number of editing options in the Rack alone guarantee that with just a few minutes’ tweaking, you’re guaranteed to pull up a unique tone that is catered to your needs.
I mostly explored the metal amp tones since that’s what I use the most, but there is a huge variety of clean, crunch, and vintage amp tones as well. This amp isn’t really aimed at any one genre, it’s pretty much evenly spread across all kinds of users. Every manner of tone tweaking enthusiast will have a fun time exploring the myriad options the Rack offers. I don’t know that a hardcore blues purist will choose the Rack over a vintage Twin Reverb, but anyone with more varied needs looking for something less finnicky and more modern with the option of sounding like a vintage Twin Reverb should look into the BIAS Rack (or BIAS Head – they’re identical aside from the form factor).
The rear panel features a chunk of output options that allow you to go direct with balanced XLR or unbalanced 1/4″ while simultaneously running a physical cab from the powered 4-16 ohm out. Full MIDI in/out/through jacks and a footswitch jack give you multiple options to control your amp in real time, and of course, there’s an effects loop.
I feel like the main areas the BIAS rack could stand to improve are the variety of tube types that are included, and the variety of amps in the stable. Luckily, these are things that I’m sure can be easily added into firmware updates that PG will release periodically. Try that with a classic tube head! For more info on the BIAS Rack, check out Positive Grid’s website.
