REAL Tube Overdrive 901 by B.K. Butler Review

 A favourite of Billy Gibbons, the Real Tube “901” seems to be the lesser known (and less sought after) brother to the classic Tube Driver used by both David Gilmour and Eric Johnson.  With the addition of the Mid control and unique enclosure you would think it would be the preferred version, but that doesn’t seem to be the case, and that makes this pedal a hidden gem in the world of tone unknown.

  • Tube based O/D with Extensive Equalizer
  • Variable Gain
  • 3 Band Equalizer
  • Swappable Tubes for subtle Gain and Tone variation
  • Preamp capable of a fairly Clean Boost
  • Two L.E.D.s (Power and Effect Active)
  • B.K. Butler Designed
  • Soft Touch foot-switch
  • Sturdy Metal Housing
  • Stable tube socket
  • Loads of Gain AND Output

A tube-based design housed in a solid metal enclosure, the Real Tube Overdrive was a unique pedal when it entered the market and arguably still is. With a three band EQ and a wide range of “tube”gain, it can mimic many tones…but it’s true value lies in the variations it can achieve of its own tone signature .\\.

Offering a bold and throaty voice that is weighty and responsive, this tube-based preamp can go from subtle overdrive to biting distortion.  Because of its starved-plate design, it has an inherent “sag” that many find a comforting alternative to the hyper-quick sensitivity of silicon-diodes used in most pedals.  It’s thick grind is accompanied with a clarity that makes it hard to get lost within the mix.  It functions quite well as an always-on dirt pedal; it is more of a preamp that you can ride from your volume knob than just an off/on type of affair. of course with the footswitch it can get from clean to mean quickly.  It’s voice is reminiscent of a full-bore Marshall from the Seventies that has its guts hot-rodded to the limit just ready to explode.

With the wide range of the gain knob it can take you from Blues Rock to grinding Metal, all aided by it’s versatile EQ.  It’s a studio essential for anyone who deals with recording sessions that need something just a bit more “real” than the usual plug-ins have to offer…without having to drag around a large stack or keep a large combo amp in the closet.

Add to this the ability to change tubes to further shape the signal and you can spend hours in the studio with the Real Tube.  Swapping out tubes can vary the gain range and EQ, albeit to a certain degree:  this is a starved-plate design so it has it’s limitations.

The EQ is of the “active” variety, with both boost and cut.  It responds well to both subtle and extreme tweaking though set flat you can numerous sonic signatures just by adjusting the Gain and Output.  The Mid control in particular can really “voice” this pedal, giving you midrange honk and or super-scooped Thrash tones.  Through all of this it remains warm and responsive to the volume knob.  Is this the product of the vacuum tube…or just a all thought out design?  B.K. Butler strikes again!

It has it’s quirks: an odd low-profile soft-touch switch that though comfortable can make it easy to “miss a shift”, it’s mains-powered only, and as sturdy as the enclosure is, it always seems to stick out from the other pedals on the board…but these are are small complaints really…The footswitch is frequently swapped out and rarely are pedals powered by batteries these days.  The enclosure, well…there is always the rack-mountable version!

If you are tired of the many 808 and TS-9 clones marketed as “so amp-like, you’ll swear you are smelling tubes!” put the Real Tube 901 on your G.A.S. List. It’s wide range of distortion and sensitive gain-staging will keep you with a large amount of bases covered…and you won’t think you’re crazy for smelling burning tubes.



Starved Plate Preamps

The generally idea with preamps is that the more voltage applied to the tube’s anode (plate), the more headroom is available.  (This is within the limitations of the tube, of course.)  If the voltage applied isn’t high enough, or starved, it can induce it’s own form of saturation.   It is basically what you might consider a clipping diode in the form of a vacuum tube, unlike a high voltage tube being pushed into saturation.



Tones Unknown:

  • Microphonic vacuum tubes mean very little to this pedal: If you have some noisey tubes you were about to toss in the garbage, try them out with the 901!
  • Preamp tubes with less gain (12AT7) can actually give you a broader sweep of the Gain control, though usually at the cost of less overall gain!


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