BAJA Real Tube Drive pedal project

[bajaman]

Hi friends
Inspired by Dirk Hendrik's Real Tube Screamer pedal project elsewhere in this section, and after reverse engineering the B K Butler Tube Driver, and noting some similarities, i have designed a brand new design for a REAL tube drive pedal, housed in a Hammond (or equivalent NSC) 1590BB case. There are three circuit boards - a mother board that holds the footswitch, input, output and AC power supply sockets; a small board to hold the 12AX7 tube and it's passive components, and a board to accomodate the driver dual op amp and three control knobs.
The three boards are solder pinned togaether and form a very strong structure to hold the tube and controls etc. There is only one wire to connect the board to the chassis earth.
I gave my finished prototype a run, last night at practice, and was complimented on my great guitar sound (not playing ability mind you ). Very low noise and hum levels, due to the fully regulated bipolar power supply
I will be building these on a one by one basis as time permits, and the price will be US$330.00 plus postage etc. (power supply not included)
However, you can build your own if you would like to, because I shall be placing the complete design layout, PCB, chassis, and artwork details exclusively for all registered members of the freestompboxes forum.
I may be able to supply board kits on request, but have not worked out prices as yet, because this is a very new project.
The only other piece of equipment you will need is a suitable 16vAC power supply - there are many 16vAC 1.5A types available as burglar alarm supplies - just buy one of these and solder a 2.1mm dc socket on the wires - because it is an AC supply it does not matter which way you connect the wires
I will be posting full details in the next few days - stay tuned
cheers
bajaman

[gnognofasciani]

Bajaman you're great!

[minor7th]

I will be posting full details in the next few days - stay tuned
cheers
bajaman

U da (baja)man! I'm not worthy....

What would we ever do without you, Steve? Same thing, just... less of it, I suppose!

Now, if you can do me an automatic note corrector....

[audioguy]

this sounds terribly cool!

[guiltyspark]

Nice work! You're a busy guy! Glad to see someone working on a tube pedal, I have been underwhelmed by the Chandler, Tonebone and Real Tube.

Guiltyspark

[snoof]

Interesting baja, looking forward to seeing it! Is it a high voltage design?

[bajaman]

Is it a high voltage design?

no - not this one, but I do have a high voltage design based on the Bad Cat Xtreme Tone, that I will post one of these days - very complex wiring though - this project is very low parts count and simple to build in comparison (modelled after the B K Butler Tube Drive - with a very compact layout and a couple of tweaks including a very simple tone control).
Sorry for the delay - I have been too busy to finalise the schematic, and I want to post ALL the project at the same time - not far away now, hang in there.
bajaman

[bool]

That's OT, yes, but I think that making a LA2 optical with low-voltage tubes would be very interesting as well.

[bajaman]

That's OT, yes, but I think that making a LA2 optical with low-voltage tubes would be very interesting as well.

hmmmmmm - interesting, but I have not switched my LA2A inspired Baja Optical Limiter off since I installed it on my pedalboard some months back - it does what I want - no compression until a predetermined signal level is reached - all very transparently - honestly, you would not know it is on unless you turn the tube overdrive before it up in level, then it squashes the note and gives a lovely fat sustain .
cheers
bajaman

[bajaman]

Here are some pictures of a complete Baja Real Tube Overdrive pedal - minus the case, which is awaiting powdercoating
This is a fully operational unit (although it hums a bit outside of a metal case), just completed today and worked first time i plugged the 16vAC power pack in to it.
My apologies for the poor quality etching - the board material was getting a little old (like me ). The led indicator is attached after mounting in the case by two flying wires through the holeabove the middle control pot.
Apart from this the only other wiring is to attach the board earth to the chassis through the green wire connected to the footswitch.
enjoy
project details to follow very soon - i have to go to a birthday party now though and get drunk
more tomorrow, when I awaken.
bajaman

http://i197.photobucket.com/albums/aa21 ... 001s-5.jpg
http://i197.photobucket.com/albums/aa21 ... 002s-5.jpg
http://i197.photobucket.com/albums/aa21 ... 003s-5.jpg
http://i197.photobucket.com/albums/aa21 ... 004s-4.jpg
http://i197.photobucket.com/albums/aa21 ... 005s-4.jpg
http://i197.photobucket.com/albums/aa21 ... 006s-4.jpg
http://i197.photobucket.com/albums/aa21 ... 007s-4.jpg
http://i197.photobucket.com/albums/aa21 ... 008s-4.jpg
http://i197.photobucket.com/albums/aa21 ... 009s-2.jpg

[Nikifena]

WOW!!!
Really nice construction!!
really cool!

[soulsonic]

Great Pro work Bajaman! I like how you have the attachment to the footswitch for the chassis ground.
Very slick!

[pz]

Very nice and clean build!
but.. you'll have to desolder the jack sockets to put the pcbs inside the enclosure?

[bajaman]

but.. you'll have to desolder the jack sockets to put the pcbs inside the enclosure?

No
I drilled the holes then cut the bottom edge of the hole off with a small hacksaw - I cut the AC input socket hole similarly, so that the board just slots in and is held in place by the pot nuts, footswitch and input / output socket nuts. The bottom of the case has a raised galley which pushes against the underside of the circuit board, without shorting anything out, and clamps the hole asembly rigidly. As a precaution, i cut a piece of mylar overhead projector type film and glue this the the bottom panel inside the galley walls - so, no shorting of the circuit board components to the bottom panel
I still have not finished redrawing the full schematic - big party last night - still recovering , but I will post the pcb layout and artwork etc. in my next post - just have to upload them first.
cheers
bajaman

[bajaman]

Here we go - this should get you started - PM me for higher res artwork if required
http://i197.photobucket.com/albums/aa21 ... elabel.png
http://i197.photobucket.com/albums/aa21 ... lguide.png
http://i197.photobucket.com/albums/aa21 ... Layout.png
http://i197.photobucket.com/albums/aa21 ... ivePCB.png

enjoy
bajaman

[bajaman]

some construction notes:


The status led is inserted in the top of the case and attached by flying leads through the hole on the circuit main board. The long pin wire on the led connects to the vacant pad that connects to the 7815 regulator IC, the other lead connects to the pad which is connected to the 1k5 resistor.

The input and output sockets were purchased from Aron at DIY Stompboxes store - good value for money

I used 30 amp fusewire for the wires connecting the three boards - note the wire is connected to the solder side of the tube socket board and the component side of the control and driver board.

The 10k and 47n series connection is connected to the solder side of the tube socket board.

Lightly file and tin the footswitch, before attaching the green board to chassis earth wire.

The 7915 regulator needs to be raised at approximately 45 degrees to prevent the metal tab from contacting the solder side of the control board - you may have to adjust the 7815 regulator sideways to avoid contact with the solder side of the control board as well.

When attaching the footswitch, raise it slightly above the circuit board - do not push it down hard against the board, otherwise you will not get enough thread through the top of the case to attach the mounting nut.

I tinned the board first before I attached the three control pots. i soldered these by soldering from the top and sweated the solder between the pot wafer and circuit board.

No MOJO parts were used in the construction of this project
I used metal film resistors and MKT polyester 100v capacitors.
The solder used was Ersin Multicore Savbit 60/40 crystal Flux non rohs too.

My thanks to Dirk Hendrick and B K Butler for their inspiration in the creation of this project. Please feel free to ask any relevant (or irrelevant ) questions regarding this project
cheers
bajaman

[John Lyons]

Very nice mechanics there!
Thanks for you hard work here.

John

[Rmanen]

That build is a work of art It doesn't even have to sound good How did you come up with the idea to do the tube like you did, and how did you go about creating the pcb after that?

Rob

[bajaman]

How did you come up with the idea to do the tube like you did

Well - I have tried putting tubes in 1590BB boxes many years before, but I guess it was the Real Tubescreamer project by Dirk Hendrick in this section of the forum, that inspired me to use a small sub board for the tube.
Also, I had just extensively modified a Behringer VT911 Vintage Tube Overdrive, after reading that it too was based on the B K Butler or Chandler Tube Driver pedal - the Behringer has a small sub board for the tube too. Before you rush out and buy the Behringer though, you should know that it is the worst sounding piece of shit distortion pedals I have ever heard
it runs off 9v DC, which is 3.6v DC less than what the tube heaters require, and the design of the tube section is nothing like the B K Butler or Chandler - it bears an uncanny resemblance to the original patent or Jack Orman's Tube Driver schematic.
My design is not based on the patent or Orman's schematic

how did you go about creating the pcb after that?

i used to use Protel autotrax program, many years ago, but because of lack of practice, I have almost forgotten how to use it properly, and the latest version is way to complicated for a simple guy like me - who needs 10 layers of board etc. for stompbox pedals.

So - i use a graphics program - CorelDraw version 11 (I have version 13 or X3 too, but version 11 works fine for me).
With Corel, I can design and draw my own pads and lines etc, curve them, or incline them at any angle - not just 45 degrees.
I then can generate parts layouts, front panel labels and chassis drilling templates directly from my PCB drawings - helps enormously with lining things up correctly.
After seeing Dirk Hendrick's Real Tubescreamer, i thought wouldn't it be easier to mount the tube board direcly to the main board without the need for any offboard wiring - the control board with the driver IC connects to the small tube board as well, which forms a reasonably rigid structure to keep the tube horizontal and therefore parallel to the mainboard.
I guess using a drawing program like CorelDraw allowed me to make easy measurements to ensure that all the connections between the boards lined up correctly. I etch my own boards, go cross eyed drilling them and then insert all the components and solder by hand - i will not by outsourcing with this project - hand built by me alone
cheers
bajaman

ps: PM me if you do not feel up to building your own - I will happily build one for you for a reasonable price

[Rmanen]

ps: PM me if you do not feel up to building your own - I will happily build one for you for a reasonable price

Hmz I'd love to try something like this, been looking for a good reason to get into tube circuit designs. Problem is, I'm a bass player, and I still haven't found a decent sounding tube OD that works on a bass .

Got Samples?