Secrets Revealed!!-What's Inside This BK Butler Tube Driver Real Tube Overdrive

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Today we look at what's inside this Tube Driver. BK Butler's original hand made Tube Driver guitar pedal used by Eric Johnson, David Gilmour, Billy Gibbons, Joe Satriani, Kenny Wayne Shepherd, Robbie Krieger, and many other pros.
www.butleraudio.com/
www.lpdpedals.com

[@Graywoolf25]

finally some one that goes into every nook and crannies of guitar pedals. Your awesome, please keep posting more videos like this. Satisfy my geeky engineering needs =).

[@DMSProduktions]

That is a very nicely built pedal. Good to see it done well!

[@marktaft6467]

a very cool review , thank u LPD

[@BenCoombs]

Very cool break down of this pedal!!

[@arensel84]

Just found your channel and subbed. Great work here!

[@davidjonorato3554]

A great classic pedal as used by Eric Johnson since the mid 80's.

[@CraigRMerriman]

Thanks! Very interesting.

[@MrMongo321]

I love the LPD 68 drive pedal the most!

[@LawrencePetross]

mrmongo673 me too Mr Mongo, me too!

[@fattone]

I know this is an older vid, but whats your take on the variations in pot values for the Hi and Tube Drive in these older models. They can vary from 100k all the way to 1Meg. I have an '86 that had all 100K except for Hi with 500k and an '87 with 100k for Level/Lo and 1Meg for Hi/Drive (the Drive pot has a 1Meg resistor soldered on the lugs.

[@Charles75N]

Great video.

[@stephenchow5161]

wow. thanks for this. subbed.

[@lushkordz6643]

I love these Inside The Box video m@n^^ ...im looking to make a couple of Mods on a ENGL E530 preamp to remove the harshness from the Lead Ch. (the Clean Ch. is pretty nice & smooth) N maybe add a Tube stage in order to bring some harmonic fullness in this HG Ch. You've got some insights on this type of Mod ? ((a friend of mine who's a Tek guy N already did it, will be here to give some help))

[@MattJarz]

Love the video, might be cool to add in a small sample of how it sounds. Thanks

[@LawrencePetross]

Have a listen here kzbin.info/www/bejne/Y33Mlnhvf7CkrtE

[@garrandsmotorsports4498]

So i have 2 of these and my 86 version has much more gain and volume than my 87 version at the same settings. the 87 has 10k resistors on the back side and my other 86 one has a 22k and a 47k red red orange. Hard to know which was gilmour used for pulse Im thinking the 10k version one because based on his settings it didnt have much gain

[@kricet77]

Классный разбор и комментарии.

[@JamesKruseArtist]

The pedal I got from BK has a bias control on it that can be turned to controlled tube bias. I have nos tubes for it from 1967 but haven’t had the guts to try them yet :-)

[@conservativestrawman9837]

This guy was working with a knock off, the bias control model is one of the real BK units

[@PANICBLADE]

@@conservativestrawman9837 This is not a knock off, it is one of the earlier units built by Butler but distributed by Chandler. Also not every real one with a bias control. From the Kitrae site: TUBE DRIVER VERSIONS - There have been numerous version of the Tube Driver made since the 1980s, but these are all of the 4 knob versions. A mostly complete list of all the other versions can be found HERE. •1985 - B.K. Butler/Chandler Tube Driver. Marked TUBE DRIVER™ and CHANDLER INDUSTRIES-PATENT PEND. on the front. •1986-87 - B.K. Butler/Chandler Tube Driver. Marked TUBE DRIVER®, Concept & Design: B.K. Butler and CHANDLER INDUSTRIES, INC on the front. •1988 - Chandler Tube Driver. Knockoff made by Chandler after Butler parted ways with them. Only marked with script Chandler logo on the front, no BK Butler. •1993-94 - 911 Tube Driver - Made by Butler's Tube Works company. A four knob version of the Tube Works 901 Real Tube pedal, which was an improved Tube Driver. •2005 - 911 Tube Driver. A reissue of the 1990s Tube Works Tube Driver.

[@eyesintheskies]

Nice it’s been 3 years , you tried them yet, I have the effectrode tube drive which is real easy to swap tubes on, trying to work out whether I really need one of these or should just buying a selection of vintage tubes, so if you can recommended any 12ax7s I’d appreciate it eBay is a minefield for valve shopping!

[@michaelk148]

Cool video! Thanks! I am in Europe, I bought an original BKB export model back in 1987, which I still have, and just of curiosity I opened the back panel to see what's in there. I noticed that the power transformer reads 115V which means that I run the pedal with wrong voltage all these years. That should be a mistake on the ordered butch I believe. Interestingly the pedal still works but with a wrong tone maybe??

[@pir869]

Which means you've been supplying the tube with 24Vdc instead of 12Vdc,though it may sound slightly better,the op-amps are more than likely running of off too high a dc supply,possibly near the limit they can handle.

[@sparkyguitar0058]

I also have a older 3 knob Tube driver that has been modded with a bias knob by Fromel. I'm running a 12au7 tube and at 18v on my board. It's not a clean sound but it's cleaned up a bit over a 12x.

[@simonkormendy849]

I noticed that they don't use any shielded audio wire for the input-wiring, just some stranded-core wire.

[@pir869]

Because this is a starved voltage tube pedal built to make as much profit as can be made for as little outlay as possible,starved tubes are just a gimmick,the same or better can be done for pennies with solid state.

[@catsven1973]

I opened mine to change the tube 3 years ago, filmed it but didn’t post it ..

[@markwood3389]

now do the rackmount version, and compare .that would be cool to see.

[@hazix8094]

I used this 120V B.K Butler tube driver into a Australian Power supply. It was 220V which blew the unit. They had advised me and shipped me out a new transformer of 220V. Is it easy to switch out and install?

[@LawrencePetross]

It should be and their support should have sent along documentation for the install. if they did not, I would contact them directly.

[@starckwest6358]

Thks

[@michaelscott9995]

Love your vid and great information. I own one of these and believe the transformer is going on it.. The one negative on these BK tube drivers is the onboard transformer and potential for noise/interference.. How difficult would it be to convert it to a brick style external power supply?

[@LawrencePetross]

Replacing the internal transformer with an external brick would be tricky and probably more of a pain that just replacing the existing transformer. The stock transformer supplies both the tube filament voltage and the audio circuit voltage. Converting to external supply would require a substantial bit of rewiring. Butler is still making these, so I would recommend contacting him to see if they have replacements or are willing to do the conversion for you.

[@michaelscott9995]

@@LawrencePetross Thank you for the feedback and info.

[@RPF3146]

do you know the plate voltage of the 12AX7? That's a pretty hefty power transformer and even a a 1:2 step up ratio and a simple secondary side rectifier and could produce around 300VDC, No? I can't get a clear answer anywhere on how high a voltage this preamp tube runs at. Thanks for the video.

[@LawrencePetross]

Ryan Foarde the power supply is +15, -15 volts DC. The tube supply voltage is 30 volts DC.

[@TheTubeDude]

Find all engineering info in the RCA Tube Manual #21. I still have mine from 1967.

[@lordlucan529]

@@TheTubeDudeThats a gem! Also came here wondering why the plate V wasn’t in the hundreds, found the characteristic graphs pretty quickly. Gotta love the intro paragraph as well!

[@alexsternwart7057]

Hi top video! May it is possibe to avoid the transformer and put that pedal in a smaller box? It takes a lot of space at the board and i would like to use one power supply for all my pedals togehter.

[@LawrencePetross]

Alex Sternwart hello! These used a step down transformer that took line voltage down to +-15 volts DC. It would require a complete redesign of the power section of the pedal. As well you still have to find room for the tube. The second version (in the blue vase I believe) did this as you suggest worth an external power supply but there are folks who say they don’t sound the same as the originals with the on board transformer.

[@alexsternwart7057]

@@LawrencePetross Thank you for the fast answer! My suggest was that inside is some free space and would become a bit more if i would take away the transformer. The target would be the size of a strymon riverside for example. There re some power supplies they can switch from 9/12/18.Would that help to avoid the complete reconstruction of the curcuit?

[@sparkyguitar0058]

@@alexsternwart7057 The 1st Butler Tube Drivers were 3 knob 9v battery powered. Batteries didn't last long, so most use a Boss style 9v per supply. I have 1 of those that has been modded with a bias knob. It's on my board, not the big 1 with it's own pwr cord. This thing is GREAT. And only for $165.

[@drivers1959]

This tube driver actually has Chandler written on it..yes Chandler industries distributed but ended in 1987 After that BK continued with his current tube driver which is still available to this very day

[@robertdrewes3062]

I was hoping to restore my AC powered Tube Driver Real Tube Overdriver, Concept and Design by BK Butler. The original grounded outlet 3 conductor power cable was replaced with a 2 conductor dis-connectable power cord. I noticed in the video that there was no ground wire connected inside the enclosure. Are my eyes playing tricks on me? I think this means the 3 conductor power cord provides no ground. Converting back to 3 conductor power cord would provide no benefit. Is the power cable ground connected to the chassis and not visible in the video?

[@bankersbanker7301]

How difficult would it be to add a mid-pot? Also what about adding an output buffer?

[@LawrencePetross]

Pretty straightforward. Just exchange a pot for the fixed resistor. For value is go with twice the fixed resistor value so you can have some boost as well as cut (technically since the stack is passive it’s just less cut, but that’s not usually how we hear it). For adding an output buffer, I’d recommend grafting in the transistor buffer from the TS-9 or equivalent. Just a few parts and it’ll drive plenty. Adding the output buffer may change the tone and feel though as you are altering the loading of the circuit.

[@glennray1901]

You read my mind... a year ago! :-) I wonder if a sweep-able mid would be doable.

[@MrSpock]

Nice video. But I believe it’s actually called a circus board 👍🏻

[@TheRealSlickRick63]

Hi, Lawrence. I see that the B.K. Butler pedal is point to point hand wired, which I'm sure drives the price up considerably. My question is about point to point hand wiring vs solid state circuitry mounted on a printed circuit board. There seems to be a huge concensus saying analog hand wired equipment produces sound quality that is far superior. Honestly, I'm not 100% convinced. The advantage I do see is that its easier to repair and/or modify a point to point wired piece of equipment. What are your thoughts? Is there much truth to this, or is solid state gear getting a bad rap?

[@LawrencePetross]

High Rick, A well design printed circuit board is just as capable of delivering the sound quality level of point to point. After all, copper is copper. If you maintain the same basic standards as you would with point to point, there is not going to be any measurable difference between the two. I do agree, point to point is much easier to repair when the need arises. Now you mentioned solid state and that is a different kettle of fish from pcb vs point to point and better left for a different discussion. Thanks for the question!

[@robertjoshlin8674]

Hello Rick, The BK Tube Driver circuit is hardly PTP but instead laid out on a printed circuit board (PCB). That being said PTP is more robust and durable over time where high voltage and heat are concerned. However. the BK Tube Driver circuit after the transformer contains neither. I'd say the tone and reliability on the BK using the PCB speaks for itself considering this classic pedal has played a central role in the tones of David Gilmour, Eric Johnson, including countless others and would not benefit from PTP in any way.

[@RocknJazzer]

this pedal is not PTP the whole audio circuit is on the PCB. This is basically a cheap opamp slamming a low voltage starved tube circuit, and it is fuzzy and undynamic compared to real high voltage run tubes. I dont care who famous played it in the 80s or whatever, I played it and think it sucks

[@BluegillGreg]

Robert Joshlin The circuit as manufactured by Chandler is done on a pcb. The circuit as hand manufactured by B.K. Butler is done on a point to point.

[@pir869]

True PTP does not even need a board,though only for structural strength as far as component leads go,tag strips,eylets,turrets,pcb,all can be bad all can be good,design and layout make or break the deal.I used to use turret pins when building tube amps,the pins can act as ariels picking up static voltage fields,low profile is generally best,but layout again is one of the biggest deciding factors,especially in high voltage realms,thought this pedal shown here is voltage starved and not exactly going to be much of a problem,other than EMF coupling into the tubes metallic parts.

[@brianmckenzie1318]

Be patient now...I'm pedal dummy.....ha ha ha! I would assume the power to the tube gives the amount of "overdrive" in the pedal? If the pedal didn't use a tube, would you something like a JFET (I've seen the term, but really do not know)? For the tone stack, is it the filtering of those frequencies that give different overdrive pedals their tonal characteristics? I hope some of this made since, as I really do not know how all of this works!

[@LawrencePetross]

Brian M hey that's what this is all about right, sharing info for better understanding. The tube requires 2 voltages, one for the heating element and one for the amplifying elements. Tubes are happiest with higher voltages, the 12AX7 likes 150-300 volts on its plates to sound like we expect tubes to sound. In the Tube Driver, the tube has about 30 volts on its plates. This is known as "starved plate mode". In this mode the tube overdrives and distorts the signal much easier and in a very different way from its high voltage mode. Not better or worse, just different. Yes, some pedals use JFETs for the amplification and clipping devices. The can be used like the tubes are used and in many different ways as well. Generally, JFETs are happiest running at much lower voltages than tube, 5-30 volts, which is why you see them so often in pedal circuits. In the Tube Driver the tone stack is after the distortion. It is filtering in much the same way as an amplifier tone stack would. Yes the filtering, before, between and after the clipping, is what gives an overdrive/distortion a majority of it's character. The way the signal is clipped gives it the rest. This is why you see so many different dirt boxes. Even minor changes can have a major impact in tone and feel.

[@brianmckenzie1318]

Thanks for the break down Lawrence! Much appreciated!!! So cool that you do this, my nerd side loves it!

[@RobertLongM]

Thats a 1987 ! That’s awesome I got a newer with Bias knob. Not so good as that one, has more noise. Not sure why

[@sparkyguitar0058]

I don't agree with you. Maybe yours but I have the new 5 knob sitting on the shelf and it's quiet enough. Also have an older 3 knob modded Tube Driver on my board. It's mod is the bias knob, done by Frommel, very clean. I'm using an old RCA 12AX7 with a metal tube cover on it. For "more power" also running on 18v pwr. Great sound,tone, and size. Stacks nice with a Meat and 3 modded Soul Food and a Alchemy modded Blues driver. 3 drives on my board means none are really heavy gain for most part

[@RobertLongM]

@@sparkyguitar0058 I had a few techs who got the same one - and they noticed a difference... even found someone online here on KZbin noted the same... Frankly I don't know why

[@sparkyguitar0058]

@@RobertLongM Wow That's new news to me. I've opened my up and really doesn't look much different than my modded 3 knob Tube Driver. And the 5 knob doesn't make any special noise to me. I can't say much about the 1 on my board cause I have a BBE mini sonic stomp starting my board and a silent-modded 10 band E Q ending my board. It's a pretty quiet 16 pedalboard

[@tunaXonXtoast]

Why no mid resister?

[@LawrencePetross]

tunaXonXtoast it has a mid resistor, just no mid pot

[@lpmanbrown6445]

Are these better than ibanez ts9

[@johnanderson60]

in short. Effing, yea, its the real deal. YES

[@kricet77]

Буду рад Вашим новым видео.

[@whynottalklikeapirat]

A mouse lives in there with his family and the kids make the noise :D

[@pir869]

Maybe i'm a snob technician,maybe i'm a purist,but these pedals run the Valve/Tube in voltage starvation at 12Vdc,this does not even register on the data sheet family curves for the 12AX7/ECC83/7025 etc. To get the full richness of tone you need to run these hollow state devices at least at around 100Vdc or you run them in the most on linear portion of the transfer curve,which should only happen when you "OVER DRIVE " them and push them into the non linear portion and thence to cut off ,not always near cut off,for a buzzy solid state type distortion. The whole thing is a gimmick and can be recreated for pennies using diodes,there is no touch sensitivity at 12Vdc,the bias voltage range just is not there to allow reasonable input voltage swing. Sorry guys and gals but if you want tube sound,ya gotta run 'em as they were intended to be ,not starved of voltage supply. No intent to be critical of the video BTW,just telling the truth about these low voltage starved tube pedals,i could churn them out,but i have a conscience regarding these things,BS is BS,but if you like the sound and don't know any better or how good it can really be...............

[@LawrencePetross]

All true and the reason I don’t do a low voltage tube pedal. Appreciate the detailed explanation 👍🏻

[@davidgregory7702]

I can think of at least one player that would disagree with you. Well actually 4 David Gilmour,, Eric Johnson, Joe Satriani, and Edward Van Halen. You''ve heard of the "brown" sound, a term coined by Edward to describe a sagging power supply starving tubes for voltage . He describes it as the sound when the tubes get all "browned" out which is an electrical term for describing a power outage or a device that was experiencing a power outage or reduction. This is what he was recreating with the variac and is what starved plate designs are emulating. I have a Dean Markley Overlord which is a clone of this pedal and it is a straight up marshall in a box. I assume they changed some component values..Starved Plate designs aere not doing nothing just because thre is no published curves for them. Tube designers just could never fathom running a tube at that low of a voltage so never made curves or published curves for that range.

[@TheTubeDude]

So the signal is affected by Solid-State OpAmp just as much as by the 12AX7. A harmless little fraud? When an African Grey Parrot mimics the call of the Lady Gouldian Finch, is the song any less beautiful? David Gilmour might want to know.

[@Shiloh7377]

On BK Butlers web site it says this, and I quote "ORIGINAL TUBE DRIVER DESIGNER’S GENERAL WARNING! Some used 4-knob Tube Drivers marked ‘Chandler’ are NOT the original design by BK BUTLER! All authentic Tube Drivers have “Concept & Design: ” on them. Pedals with separate AC power supplies or ‘wall warts’ are NOT original and do NOT sound the same! Order here and get a REAL BK Butler hand-made Tube Driver!"...

[@guitarguy382]

Dating a Butler Tube Driver….. Example: 7071416 = July 14, 1987, the 16th unit in the batch. I’d contacted Mr. Butler years ago and asked if he could provide a date for the driver (4-knob) that was given to me more than 20 years ago by a co-worker. I provided the S/N, and Mr. Butler provided the date. (The co-worker was on a job-site and spotted it sitting atop a trash-compactor.) Him: “You play guitar, right?” Me: “Yeah. Why?” Him: “I found this.” Me: “Oh, WOW!” Took it home, plugged it in……..worked like a champ. Still have it.