B.K. Butler and THE one and only TUBE DRIVER

An interview by John Roscoe for the TONE FROM HEAVEN

Tube Driver is the original brain child of B.K. Butler which started the modern trend of tube overdrive devices. Known throughout the world as the favorite pedals of Eric Johnson, David Gilmour, Billy Gibbons and countless others, the Tube Driver has maintained a foothold in mainstream tones since the ‘80’s. With the movement of many musicians to have vintage effects and get away from the multiprocessors to some degree, the original Tube Driver developed by BK Butler has been one of the most recognized and most sought after effect.

Mr. Butler has taken time out of his busy schedule to answer a few questions for The TONE FROM HEAVEN. As many of the visitors to this site are aware, David Gilmour has used the Tube Driver since the late 1980’s and it has remained a vital piece of his recording and touring arsenal. So without further ado….

Questions are in bold from John Roscoe while answers from BK Butler follow each question in blue:

“…There is no Butler / chandler Tube Driver really; …matter of fact it’s ALL Butler…”

What lead to the creation of your Tube Driver for music (guitar)?

I began playing around with tube overdrives when I first heard Deep Purple’s raging Hammond organ sound on several of their live albums back in the 70’s. My dream was to have a B3 and a Leslie 147, but alas that was way over my budget. My Dad let me have an old tube-amped stereo record player, so I ripped out the innards and started playing around with overdriving the phono input with my Farfisa Mini Compact organ. It sounded pretty good so I put it in a Radio Shack metal cabinet and called it Tube Driver. The guitarists in a local band tried it out and loved the sound. I then simplified the circuit, shrunk it down, and built several similar “Tube Drivers” for friends back in ’75 or so… Around 1978 I went to work for Carvin and after learning a bit more about guitar amp design and prosound in general, I decided to make the first Tube Driver pedal for profit and advertised in Guitar Player in 1979. It didn’t have any EQ controls, just Drive, Sustain (built in compressor) and Output level. Sold a number of those in old Bud aluminum boxes, painted blue… Started Audio Matrix in Carvin’s old building in 1980 and first designed & sold the “Mini Boogee” honestly not realizing the TM problem with Randal Smith’s “Boogie”. He was a real gentleman about the situation, so I promptly changed the name to ‘Mini Matrix’ at his request. I designed several rack mount tube overdrive preamps at Audio Matrix and learned how to mix op amps and tubes for a very genuine tube overdrive sound. In 1984 I was working with Dean Markley Electronics as the engineer. Virtually all of the original DM guitar amp products have my designs of tube or FET overdrives in them. Dean was looking for new products and wanted to make something along the lines of the Rat, so I proposed that we use tubes. I made up a prototype, but Dean didn’t really care for the sound. Never really knew why. Chandler (who had earlier sold some of my old Mini Matrix pedals, etc, did have interest in the Tube Driver and wanted to market it for me. As Markley was in the process of winding down operations at his electronics plant in Kansas, I needed a new way to make a living. So through the ‘mother of invention’ syndrome I came up with the new TD ‘look’ and designed what has now become known to most of the guitar world as the pedal Eric Johnson made famous (see Guitar Player Magazine, May ‘85 issue, I believe). A little known fact is that Eric purchased at least 6 of my Mini Boogie /Matrix pedals long before he became a world-wide phenomenon. -That’s the short story of how the creation of the Tube Driver came about.

What makes your Tube Driver stand out from the plethora of other tube driver effects?

First of all, I’m not a guitarist. I had no predisposed bias towards any type of existing guitar overdrive, amp, etc., when I set out to design the Tube Driver. I asked a lot of guitarists what sounded good over the years, and they really helped a lot. One of the guys I thank most is Tower of Power’s Willy Fulton. Just a wonderful and great guy. Also, for a keyboard overdrive to sound good, it must be very true to the harmonics. A good guitarist can ‘bend’ each string within a chord a bit to sweeten up the right harmonics, but a keyboard is never really perfectly in tune due to its stretched and tempered scale. I chose tubes because they were much more forgiving and better sounding than solid state overdrives for keyboards. I found that if the overdrive sounded good on my Rhodes and Hammond, it probably would do pretty well for guitars. Of course there’s a lot of electronics and technical voodoo that enters into the design too and I know how to bias and drive the tubes in ways that elude most engineers. But I still consider myself to be more pure musician than engineer. Most electrical engineers I know are definitely not musicians and that’s caused a lot of misunderstanding throughout the audio industry. All my designs are primarily driven by their pleasing musicality, NOT by arbitrary electronic specifications.

Why did you stop making the Tube Driver? (Split from Chandler?) Any reason why you got out of the performing music industry (I.E. making effects)?

Actually the Chandler thing was a relatively minor incident in the overall history of my business activities. There’s not enough room here to elaborate much, but the truth of the matter is that somehow Chandler decided at one point that they had been the designer of the product, came up with the TD trademark and that I was infringing on their IP. They obviously had somebody attempt to copy the electronics and the physical design of my TD, then produced and sold them. I don’t know how many unauthorized units are out there. The mistakes inside are essentially within the EQ area and it would take too long to describe them. Also there is a basic ground loop mistake as well. The overall sound of the C copy is somewhat muted and not as clear on the upper harmonics, etc. Eric Johnson never used one of these copies as far as I know. All his pedals are ones I personally made. I never could understand why Chandler did that copy thing… They even challenged me in court and tried to convince the judge that Chandler was the actual owner of my design and the Tube Driver trademark. But the truth was obvious: In the end what was mine to begin with remains mine still… I then designed the black Real Tube pedal in 1986 which I still think is a superior pedal in some ways to the Tube Driver (ZZ Top’s Billy Gibbons agrees) and then went on to design all my Tube Works SKUs: MosValve, Tube Works Real Tube rack products, combo amps and reverb… then the smaller 3 knob version of the Tube Driver was designed in an attempt to give an entry level price to tube lovers. Actually I never completely stopped making original Tube Driver pedals, but just didn’t emphasize them so much during the early TW years. Later in about 1993 or 1994 I revived the pedal in earnest and named it after my ‘love on 4 wheels’, the model 911. It’s ironic now that one of my current business collaborators has an esoteric speaker model called the ‘Twin Towers’ and I’m again making limited production runs of 911 pedals…. We were actually musing about that singular fact today on the phone of all things…

Can you tell us the differences between your units say for David Gilmour, Eric Johnson etc?

The David Gilmour pedals are stock and as originally designed. I just sent off 4 new innards to upgrade his older pedals last month (Dec, 05). Eric has some original Tube Drivers that I added an extra Bias pot on the rear above the jacks to allow adjustment of the ‘stiffness’ and saturation of the tube. I think I made 3 or 4 of them for him. He also uses some stock ones as far as I know. Eric is undoubtedly a big reason the Tube Drivers were ‘put on the map’ and I owe him a big “Thanks”. I am completely in awe of his and DG’s artistry. I’m also in the debt of the many other guitarists who use the TD and Real / Blue Tube pedals / racks and I have to say “HAVE MERCY” to BFG almost daily...

Can you tell us how it came about that you were hired to make new Tube Driver Units for David Gilmour for his upcoming album/tour for 2006?

Just got an email from his people and I made them for him gratis. Not more complicated than that. I have been mesmerized by PF’s subliminal tones for decades.

Have you seen how much your original BK Butler Chandler Tube Driver units are getting on E-bay. Latest was $383.00US! You were making a limited run of 6 this year, any plans to mass produce them in the future?

As I tell whoever will listen: “There is NO Chandler Tube Driver… Never was a Chandler Tube Driver! They just marketed it for a while.” But I do understand the confusion caused when I allowed their name to be included on my product. My lesson was well learned… enough said.

Many will be glad to know that I’m now making a few new Tube Drivers per month again due to word of mouth ‘push’. They have better components than the original as far as pots, capacitors, etc. I still use metal Switchcraft jacks and they’re completely true to the original design. I may open up an Ebay store later this year if the demand continues to grow. I don’t think Tube Drivers can ever be mass produced and sound right because I really do voice and check out each one by hand. Tubes are tricky little bas---ds. Each one has a personality of its own. It’s a very subjective thing to grade how they sound. I spend more time than it’s worth financially to me to make them with all the other projects I’m involved with at Butler Audio. (See my current stuff at www.butleraudio.com)

But I build the Tube Driver pedals for the love of music; the musician in me truly understands why they are so special to serious guitarists. If I could, I’d spend all my time at the keyboards still. I will always be a musician first.

Did you have any idea that your effect would be so sought after, after all these years?

No. It’s an utterly complete surprise.

Did you have anything in mind when you created the Tube Driver? Where would it be best utilized? Stand alone or in conjunction with other effects (boost effect)?

When I designed the original Tube Driver pedal, I was mostly thinking about survival. I knew it HAD to be good, right out of the gate! Dean Markley was shifting gears with his electronics company and I was not included in the plans. Left high and dry in Salina, Kansas (of all places) this adopted So Californian was literally like a fish in a wheat field. So I conjured up all the courage and experience I could muster and my wife and I worked day and night in our basement production room to build Tube Drivers. The Real Tube pedal was different however. This is true: I voiced the EQ and harmonics by playing the chords of Tush over and over again on my Rhodes to eventually get it the way I wanted. Later when Billy Gibbons bought one from a music store and called me up to say “Hey” I just couldn’t believe it. He later ordered them from me by the dozen and gave a lot away as gifts. Recently I had the pleasure of working with him on an automotive Tube Driver amp install for the Rides show on TLC. He has this amazing gold ’61 Caddy. He then graciously invited me to his Hollywood home and there I spied one of my old Real Tubes lurking in back of his practice amp! HAVE MERCY!

Technical Specifications of the Tube Driver

Voltage Requirement (USA) 120 VAC, 10 Watts
Tube Type 12ax7a (Selected)
Input Impedance 1 Meg Ohms
Overdrive Sensitivity -55 dBV (1.35 mV)
S/N Ratio 70 dB (Typical)
Hum and Noise -80 dB (Typical)
Output Level 0 dBV (.78 Typical)
Physical 4.0” x 7.0” x 3.0” 3 lbs


I’d like to thank BK Butler for his time for this interview and for making a great effect that has lasted the test of time.

For more info please visit Mr. Butler at www.butleraudio.com