freestompboxes.org

This is NOT a beginner's project.
This was traced from a recent B K Butler pedal and has the bias pot modification which alters the voltage on the cathodes of the 12AX7 tube.
You will need a suitable 12vAC power pack for this pedal - the original has a small toroidal mains transformer fitted internally near the front of the case.
The input and output sockets are isolated from the chassis by plastic insulating spacers. The earth pin on the input socket is connected by a parallel connected 100 ohm resistor and a cheap 100n mylar capacitor to the chassis near the front of the case.
There is no mojo components in here - just cheap mylar greencaps and standard metal film resistors - so It won't sound very good - tell David Gilmour and see if he cares - he has two of these exact same pedals in his Pete Cornish pedalboard
The additional bias control pot is mounted above the input socket on the rear panel - I preferred it without the additional bias resistance and capacitance - but others may find this B K Butler mod useful.
I have not redrawn the schematic yet - it should be up in the next few days - it is not the same as ANY of the many schems floating around on the net by the way.
It uses a TL072 op amp and 47k plate load resistors and many other subtle changed components - more later.
Good luck if you want to build it - it uses a double sided circuit board.
How does it sound? I did not care for it - but then I have been spoilt by a real tube overdrive ( 250v dc plate load feed as opposed to this 12v beastie) I think you may be able to improve it's sound by using a higher spec op amp such as the excellent Burr Brown OPA2134 and by using better quality metalised polyester or polystyrene film capacitors - who knows??
Anyway - big drum roll................................................................

The B K Butler Tube Driver files
Tube Driver Label
Tube Driver Overlay
Tube Driver Top Layer PCB
Tube Driver Bottom Layer PCB
Tube Driver Footswitch Wiring Code
Tube Driver Bottom PCB layer parts placement and bias mod

enjoy and Merry Xmas
bajaman[/url]

Ho Ho Ho Ho Ho.... i knew it ... Santa does live down under !!!!

.... not interested building one but good reff help for repairs ....thanks Heaps.

That's very nice of you Bajaman! You do such nice work, espedially for something you didn't really care for. When etching a double sided board, can the resist be applied to both sides and etched simultaneously? As opposed to etching one side, masking that, and etching the other side. What do you folks use for the overlay art? I don't suppose anyone sets up a silk screen process for so few boards. Thanks again Bajaman.

That's very nice of you Bajaman! You do such nice work, espedially for something you didn't really care for

thank you - Just because I did not like it that much is no reason not to post it - there are many folks that love it - just like the Klon
Presenting it here as a project gives folks the opportunity to try something a bit meatier than the SHO or endless TS clones, and it is a double sided board too.

When etching a double sided board, can the resist be applied to both sides and etched simultaneously

yes - just be careful not to scratch the resist off.

What do you folks use for the overlay art

I normally print it and stick it on the top of the board - works very well for one off designs, but with this one you will just have to refer to the overlay because of the tracks on the topside - make sure you connect all the top and bottom layer pads though - unless you get the board made professionally with through plated holes

have fun
bajaman

Cool one Steve!

Any photo's of the result?

Any photo's of the result

Well - I have not built it ......yet.
It came through my workshop, so I did take lots of pictures and noted component values etc., I will post some photos of the original soon
cheers
bajaman

pictures:
https://i197.photobucket.com/albums/aa2 ... esmall.png
https://i197.photobucket.com/albums/aa2 ... esmall.png
bajaman

Interesting..... seems to be from the 90´s .... the youngest version I am aware of.....
Its nearly identical to that hand-drawn schematic circling around. Do you have that baja ?

analogguru

Its nearly identical to that hand-drawn schematic circling around. Do you have that baja ?

Yes AG I do have it but this is not the same.
I also have your schematic and JD Sleeps schematic etc. - none of them are the same as this one. I will draw the schematic and post it very soon
Cheers
bajaman

W Baja....
...another GREAT gift!!

Here is the schematic as promised
bajaman
B K Butler Tube Driver schematic

I purchased a Behringer VT911 (reputedly similar to the B K Butler Tube Driver), took it apart AND ..... I have to tell all here that this is not even remotely similar to the B K Butler Tube Driver.
First it runs off 9v dc , NOT 12vAC (which is converted to +12vDC and-12vDC in the B K Butler)
It has a crappy single knob tone control in place of B K Butlers HI and LO controls.
It has a Coolaudio brand chip - unsure what it is - looks like a quad opamp SMD device in place of the B K Butler TL072 or 4558 dual opamp.
AND ...................it sounds like a badly biased germanium Rangemaster - you know, that shitty gated distortion effect in comparison to the smoooooth sounding B K Butler Tube Driver.
No wonder Behringer discontinued it - does any one have a schematic for it????
My local Behringer tech friend does not have it - I am contemplating doing some mods to make it a useable unit - then again, maybe I will just put it on the local Trade Me site (NZ Ebay) and see if I can get some money back
Anyone with a schematic - factory or otherwise email me baja002@clear.net.nz - I will not say where I got it okay

Do yourselves a favour DO NOT BUY one of these - build the B K Butler Tube Driver instead
cheers
bajaman

For your information - my friend who lent me this unit to trace, Loooooooves it, he reckons it is one of the best overdrives he has ever used ( has not tried mine yet )
cheers
bajaman

That board looks just like one I was given a few years back. The original owner had tried to mod it and burned up a lot of traces on the board. He ended up using the pots for something else and gave me the board along with a bunch of other DOD and Arion boards that were also damaged. I'll have to rummage around and see if I still have it.

That board looks just like one I was given a few years back

Well - lucky you - now you can rebuild it and enjoy
bajaman

Thanks bajaman ! Excellent work !

I have already build two of them. My first try was the GGG, i had some problems with noise even with a outside 12VAC power supply.
My second try was more acceptable, it was one layout that was floating around in the other forum but i had one problem i couldn't solve, the output signal is lower than the input when gain is set lower than +/-50% even with the Out Level at max !

I was starting my third attempt when i saw this ! GREAT !
I will start my build after Christmas.

Once more, thanks bajaman.

Hello Eloy
Please take some photos of your impending build and post them on photobucket - it is free and you can upload heaps of info - then place links here so everyone can see a finished build
do not hesitate to ask here, if you have any problems or questions - I will be happy to assist you.
Merry Xmas and looking forward to seeing your results
bajaman

Eloy wrote:Thanks bajaman ! Excellent work !

I have already build two of them. My first try was the GGG, i had some problems with noise even with a outside 12VAC power supply.
My second try was more acceptable, it was one layout that was floating around in the other forum but i had one problem i couldn't solve, the output signal is lower than the input when gain is set lower than +/-50% even with the Out Level at max !

I was starting my third attempt when i saw this ! GREAT !
I will start my build after Christmas.

Once more, thanks bajaman.

Hi ,

bajaman, thanks a lot for all that info, I just registered to this forum.
I read this thread, and it's stoped in a dramatic way .
Any results with this project?

I also built the GGG Tube Driver and it's sound real bad.

Many thanks
Dror

Hello Dror
I am not surprised that the GGG Tube Driver sounds bad - it is basicly the same as the Behringer VT911 Vintage Overdrive that also sounds bad.
Both of these are realisations of B K Butler's original US patent for a tube driver circuit - they are NOT the final realised circuit that B K Butler builds. This project IS a direct tracing from an ACTUAL B K Butler TUBE DRIVER.
If you build this, you will hear what a B K Butler Tube Driver sounds like - a lot different to those awful GGG and Behringer failures.
OR - You could build my Baja Real Tube Overdrive OR Dirk Hendrik's Real Tube Screamer - both in the ready to build projects section. Both of these projects will give you a great sounding pedal.
cheers
and welcome aboard - please feel free to share, learn, or just plain lurk - lots of good folks here, who are only too happy to answer any questions you may have.
bajaman

Thanks for the advice
Is there any sample sounds?