# Bk butler tube driver



## stringer (Jun 17, 2009)

Hello everyone. I got my hands on a BK Butler Tube driver. Never heard of it before. Read up a little bit about it. It looks like an older model, 3 knobs and 9v ac adaptor with 12ax7 tube, hand scribed serial on back. I plugged it in and gave it a try and am not that impressed. Very noisy, muddy etc. I wonder if the tube is old/crappy. I had it plugged in for about half an hour and got no heat or light from the tube ( wich could mean nothing?)Read somewhere that Gilmor uses one but with a 12au tube. I'd like to give it a try but am worried that if I use anything other than a 12ax I'll ruin the pedal. Does anybody have some advice? Maybe a list of optional tubes I could try out?

Thanks.


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## mrmatt1972 (Apr 3, 2008)

I have no opinion about these pedals, but I can say changing to a lower gain tube will do no harm.


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## gtone (Nov 1, 2009)

Good thread here on TGP, read thru:

What's so great about the Tube Driver? [Archive] - The Gear Page


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## traynor_garnet (Feb 22, 2006)

I have one of the new ones with a bias knob and I am using a 12 au7 in mine with no problems. Great pedal.

TG


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## stringer (Jun 17, 2009)

gtone said:


> Good thread here on TGP, read thru:
> 
> What's so great about the Tube Driver? [Archive] - The Gear Page



Thanks for that.


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## stringer (Jun 17, 2009)

Right on. I'm gonna give it a go. Maybe try a new 12ax also.


traynor_garnet said:


> I have one of the new ones with a bias knob and I am using a 12 au7 in mine with no problems. Great pedal.
> 
> TG


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## mhammer (Nov 30, 2007)

I'm going to make an outrageous statement, and say that if your tube amp has less than 3 tubes from the 12A-7 family, or has reverb and/or tremolo, and fewer than 4 tubes from the 12A-7 family, you may find value in the Butler box. Think of it as adding a few more cascaded gain stages that your amp lacks. If your amp already has, say, 4 gain stages (a pair of 12A-7 tubes) between the input jack and the phase splitter, then adding more may yield little of benefit. If it has a single 12AX7, doing the preamp duties (one between the input jack and tonestack/volume-pot, and one after), then throwing in another pair of gain stages may yield a creamier overdrive.


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## stringer (Jun 17, 2009)

mhammer said:


> I'm going to make an outrageous statement, and say that if your tube amp has less than 3 tubes from the 12A-7 family, or has reverb and/or tremolo, and fewer than 4 tubes from the 12A-7 family, you may find value in the Butler box. Think of it as adding a few more cascaded gain stages that your amp lacks. If your amp already has, say, 4 gain stages (a pair of 12A-7 tubes) between the input jack and the phase splitter, then adding more may yield little of benefit. If it has a single 12AX7, doing the preamp duties (one between the input jack and tonestack/volume-pot, and one after), then throwing in another pair of gain stages may yield a creamier overdrive.


 Hmm... I am really unfamiliar with the electric side of things, having been mainly an acoustic player the last few years, only getting into electric recently due to a new coworker having a place to play. I have a blues junior (bedroom practice amp) that has 12ax7 but I have no idea how many tubes it has. The amp has only 1 channel with adjustments for main volume, overdrive, bass, middle, treb, and reverb. I have been using the pedal for a few days now and am starting to get some sounds that I like. At first it sounded dark and muddy to me if that makes sense. And like everything electric it seems to work better when the volume is turned up. It's very different from my digitech blues screamer, the screamer sounding "harsher" to my ears. Off to do some research on my amp, thanks for the info.


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## mhammer (Nov 30, 2007)

According to the schematic I have, the Blues Jr has gain-stage -> volume control -> gain-stage -> tonestack -> gain-stage -> phase-splitter, with a half a preamp tube sitting idle.

So yeah, an extra stage or two of tube boosting might yield some pleasing sounds, though I don't think you want to use the Butler box in tandem with the "fat" switch on the Blues Jr, since you'd likely forfeit any touch sensitivity. You may even want to dicker with replacing the first 12AX7 tube in the amp with a lower gain one such as a 12AT7 or 12AY7 (the AT is generally easier to locate), so that the Butler works to provide gradual accumulation of gain across multiple stages.


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## stringer (Jun 17, 2009)

Oh yeah! I forgot about the "fat" switch. I'll turn that off and see what happens. The amp is 3 or 4 years old, but probably has less than 20 hours on it, so original tubes should still be okay, but I'll look into the different 12a tubes you mentioned, I like to tinker. Looks like I might be starting the journey to find my sound. We'll see. Any caveats about changing tubes? Are they like halogen bulbs? Do I have to handle them with gloves so no skin oils get on the tubes?


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## mhammer (Nov 30, 2007)

stringer said:


> Oh yeah! I forgot about the "fat" switch. I'll turn that off and see what happens. The amp is 3 or 4 years old, but probably has less than 20 hours on it, so original tubes should still be okay, but I'll look into the different 12a tubes you mentioned, I like to tinker. Looks like I might be starting the journey to find my sound. We'll see. Any caveats about changing tubes? Are they like halogen bulbs? Do I have to handle them with gloves so no skin oils get on the tubes?


Before sinking too much money in, I'd say just pick yourself up a 12AT7. That can be used in various places in the signal path, including the Butler box, to alter the gain structure in productive ways.

I don't know that tubes are especially sensitive to small amounts of finger juice on their surface, but there is nothing wrong with using a paper towel or tissue to hold them, just so they keep looking nice and shiny when they glow.


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## itf? (May 27, 2009)

stringer said:


> Hello everyone. I got my hands on a BK Butler Tube driver. Never heard of it before. Read up a little bit about it. It looks like an older model, 3 knobs and 9v ac adaptor with 12ax7 tube, hand scribed serial on back. I plugged it in and gave it a try and am not that impressed. Very noisy, muddy etc.....


Hey Stringer. The tube driver you have is not the same as the model Gilmour and others use. The reason you aren't impressed may have something to do with the tube but not that likely. That particular version was short lived for a good reason.....people just didn't like them. The Tube Driver that Gilmour et al use is the version that runs on standard AC power and has 4 knobs (Level, Hi, Low, and Tube Drive). The 4 knob versions are very smooth sounding.....kinda like a plexi that's being pushed hard. You won't get that sound from the version you have. A nice alternative, though still slightly different, is the "Real Tube" version of the tube drivers. These have 5 knobs and come in a black metal housing. The Real Tube is the version the the rev. Billy Gibbons plays. These can generally be found at much lower prices than the 4 knob versions.

That being said, you can certainly try any 12a style tube you wish. Lower gain tubes like the 12ay7 and 12at7 will smooth out some of the graininess and also bring down the noise considerably. But don't expect a drastic change. Unfortunately, the version you have just doesn't have the tone qualities you are looking for.


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## stringer (Jun 17, 2009)

That's a bummer Thought I finally stumbled across a good deal. I found very little on the net about these 3 knobers. As I use it more I don't mind it, but it sure isn't a holy grail. Oh well, I think I'll try a couple of different tubes anyways and see what happens. Thanks for the clarification.


itf? said:


> Hey Stringer. The tube driver you have is not the same as the model Gilmour and others use. The reason you aren't impressed may have something to do with the tube but not that likely. That particular version was short lived for a good reason.....people just didn't like them. The Tube Driver that Gilmour et al use is the version that runs on standard AC power and has 4 knobs (Level, Hi, Low, and Tube Drive). The 4 knob versions are very smooth sounding.....kinda like a plexi that's being pushed hard. You won't get that sound from the version you have. A nice alternative, though still slightly different, is the "Real Tube" version of the tube drivers. These have 5 knobs and come in a black metal housing. The Real Tube is the version the the rev. Billy Gibbons plays. These can generally be found at much lower prices than the 4 knob versions.
> 
> That being said, you can certainly try any 12a style tube you wish. Lower gain tubes like the 12ay7 and 12at7 will smooth out some of the graininess and also bring down the noise considerably. But don't expect a drastic change. Unfortunately, the version you have just doesn't have the tone qualities you are looking for.


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## itf? (May 27, 2009)

Hey man, didn't mean to get you down like that. By all means, try different tubes and see what you can get out of it! And, please let us know if you find a tube that works particularly well. 



stringer said:


> That's a bummer Thought I finally stumbled across a good deal. I found very little on the net about these 3 knobers. As I use it more I don't mind it, but it sure isn't a holy grail. Oh well, I think I'll try a couple of different tubes anyways and see what happens. Thanks for the clarification.


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## stringer (Jun 17, 2009)

Thanks for the kind words and guidance. Not your fault. As I said, after using it for a while, I am managing to eek out some sounds I like. Now how's about this for a brain teaser? When I turn the pedal on the red indicator light lights up, I get all kinds of dirty distortion, but I don't see any light coming from the tube and after about an hour of playing I get no heat coming from the pedal. I read on the net that not all tubes light up when they are on. Is it possible to get distortion when a tube fails? I would think you'd get nothing, but I don't know. If someone could shed a little light on the subject I'd greatly appreciate it.


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## itf? (May 27, 2009)

That's normal. The "starved plate" configuration of the tube in that particular model means the tube doesn't glow or get hot.


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## stringer (Jun 17, 2009)

Now I'm starting to learn a thing or two. Thanks.


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## stringer (Jun 17, 2009)

mhammer said:


> Before sinking too much money in, I'd say just pick yourself up a 12AT7. That can be used in various places in the signal path, including the Butler box, to alter the gain structure in productive ways.
> 
> I don't know that tubes are especially sensitive to small amounts of finger juice on their surface, but there is nothing wrong with using a paper towel or tissue to hold them, just so they keep looking nice and shiny when they glow.


I tried an electro harmonix 12a t7. It was a rainy day. To be honest, I didn't really notice much of a difference at bedroom levels. Seemed not as loud, the distortion seemed "thinner" if that makes sense, and it seemed a little more "sour"? or "orange" if that makes any sense as well. Gonna try it out at the next jam session, if they'll have me.


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## BEMUSofNrthAmra (Jun 9, 2012)

I want one of these really bad. Let me know if you want to get rid of it.


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## mhammer (Nov 30, 2007)

stringer said:


> I tried an electro harmonix 12a t7. It was a rainy day. To be honest, I didn't really notice much of a difference at bedroom levels. Seemed not as loud, the distortion seemed "thinner" if that makes sense, and it seemed a little more "sour"? or "orange" if that makes any sense as well. Gonna try it out at the next jam session, if they'll have me.


Where in the signal path did you swap it?


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## stringer (Jun 17, 2009)

Sheesh I'm bad at details. Switched it out of the butler tube driver. Like I said before, I'll take it to the jam and crank it and hear what difference it makes. When I switched tubes I kept all the pedal settings the same and with the different tube it was getting in the area of zz top.


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## stringer (Jun 17, 2009)

BEMUSofNrthAmra said:


> I want one of these really bad. Let me know if you want to get rid of it.


No I don't think you want this one. This is the 3 knob one, no bias adjustment. I read some reviews on the three knobber and som e of the complaints were that the eq was very hard to modulate with it dropping off a cliff, but I must say that the one I have seems to have a wide useable eq. It sat unused for about 10 years and was very crackly when I first turned it on, but all that noise is gone away now.


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## BEMUSofNrthAmra (Jun 9, 2012)

stringer said:


> No I don't think you want this one. This is the 3 knob one, no bias adjustment. I read some reviews on the three knobber and som e of the complaints were that the eq was very hard to modulate with it dropping off a cliff, but I must say that the one I have seems to have a wide useable eq. It sat unused for about 10 years and was very crackly when I first turned it on, but all that noise is gone away now.


If the price was right, I would take it.  I'm good with electronics and I'm sure I could fix it or even add a bias knob if I wanted one.

I'll probably end up buying a brand new one.


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## keto (May 23, 2006)

Just read a rumour on TGP...there's a new MXR pedal on Joe Bonamassa's board, which is supposed to be their/Jorge Tripp's take on a BKB Tube Driver. Could be one coming to market soon?


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## stringer (Jun 17, 2009)

Did you catch the Bonamassa special on television the other day? Great stuff.


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## stringer (Jun 17, 2009)

"If the price was right, I would take it.  I'm good with electronics and I'm sure I could fix it or even add a bias knob if I wanted one.

I'll probably end up buying a brand new one"

I was wondering how difficult retrofitting a bias adjustment would be. But the newer ones also have a separate treble and bass knob also do they not?


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## BEMUSofNrthAmra (Jun 9, 2012)

Ahh I forgot where you mentioned it's an older Tube Works 3 knob model.

Any tube amp tech should be able to install a bias knob into the unit. Might help make it more versatile.


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