BAJA Real Tube Drive pedal project

bajaman · Post by **bajaman** » 29 Aug 2008, 20:26

Hello Schumann
Yes - I used a cheap white plastic pc mount tube socket (purchased from http://www.tubesandmore.com).
Good luck with the build

bajaman

Aharon · Post by **Aharon** » 31 Aug 2008, 16:57

Wow ,finally back to my favourite corner of the net afyer a long absence..........THANKS BAJA
Aharon

Gibson78 · Post by **Gibson78** » 01 Sep 2008, 16:42

Hi bajaman, are the diodes (1N4007 and 1N4148) reversed? Should'nt the side with the band be the cathode? In the layout it shows one thing while on the build pics it show a different orientation.

Also on the schematic it does'nt show the 1N4148's.

Help!

Cheers and Beers!

bajaman · Post by **bajaman** » 01 Sep 2008, 20:05

Hi bajaman, are the diodes (1N4007 and 1N4148) reversed? Should'nt the side with the band be the cathode? In the layout it shows one thing while on the build pics it show a different orientation.

Also on the schematic it does'nt show the 1N4148's

The diodes are shown with a + to denote the cathode (the end with the band)

My apologies for not drawing the 1N4148's on the schematic - they are connected to the non inverting input of the first op amp buffer stage and the positive and negative supply rails - they are only there as a protection measure and can be left out with no effect to the normal function of the circuit. I will update the schematic in the near future.

Cheers
bajaman

Gibson78 · Post by **Gibson78** » 02 Sep 2008, 01:25

bajaman wrote:
Hi bajaman, are the diodes (1N4007 and 1N4148) reversed? Should'nt the side with the band be the cathode? In the layout it shows one thing while on the build pics it show a different orientation.

Also on the schematic it does'nt show the 1N4148's
The diodes are shown with a + to denote the cathode (the end with the band)

My apologies for not drawing the 1N4148's on the schematic - they are connected to the non inverting input of the first op amp buffer stage and the positive and negative supply rails - they are only there as a protection measure and can be left out with no effect to the normal function of the circuit. I will update the schematic in the near future.

Cheers
bajaman

Got it! Thanks for the reply!

Cheers and Beers!

PokeyPete · Post by **PokeyPete** » 03 Sep 2008, 04:56

Bajaman wrote: 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.

Greetings Bajaman.....very interesting project!

It has been several months....I was wondering if you have any available yet? Or have you decided not to proceed with this? Were you thinking of selling circuit boards only, or boards and parts as a kit?

bajaman · Post by **bajaman** » 10 Sep 2008, 02:55

At long last!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Some sound samples performed by my young friend Joe Sampson using the BRTO with a Fender Stratocaster played into a Marshall JCM800 100 watt head and Marshall 1960A Quad box. He used 2 Shure SM58 microphones to record these.

members/bajaman/Baja/Baja%20Real%20Tube ... 8/Mp31.mp3
members/bajaman/Baja/Baja%20Real%20Tube ... 8/Mp32.mp3
members/bajaman/Baja/Baja%20Real%20Tube ... 8/Mp33.mp3
members/bajaman/Baja/Baja%20Real%20Tube ... 8/Mp34.mp3
members/bajaman/Baja/Baja%20Real%20Tube ... 8/Mp35.mp3

cheers
bajaman

obelix · Post by **obelix** » 10 Sep 2008, 04:40

that sounds really good

schemripper · Post by **schemripper** » 12 Sep 2008, 02:44

I built this a couple of weeks ago and have only just been able to fiddle with it. (I had sliced the very tip off my left ring finger, which made it impossible to play for several months until it healed.

) The only variation from plan was using a 5532 for the opamp.

I found all 12AX7s tried to be a little over the top for my style. The volume knob barely got past 9am, and I was having to reel it back to the rest of my pedals.

I tried several others in the 12Ax range, and eventually settled on an old (very old, actually) Phillips 12AU7. The reduced output meant that I could push the pedal harder, and the combination of gain and volume knobs were far more responsive (read: useful). It goes from clean to the little bit crunchier than I would normally use, and since it's being pushed a bit harder sounds better to my ears.

I haven't fiddled any part of the circuit yet- I'm happy with the sound. However, Bajaman, as the designer of this great circuit, do you think anything needs changing with the AU7?

As it is with amps, though, don't be scared to try other tubes in it.

bajaman · Post by **bajaman** » 12 Sep 2008, 03:01

Hi schemripper
You could try decreasing the 2 x 47k plate load resistors - try 22k for example when using the lower plate impedance 12 AU7 type tubes - A 12AT7 might work okay in here too.

Cheers
bajaman

schemripper · Post by **schemripper** » 15 Sep 2008, 23:39

Thanks, Bajaman- will try that, and see what else I can come up with!

Thanks again for a great circuit.

Amstel · Post by **Amstel** » 16 Sep 2008, 17:46

Hi Bajaman,
Thanks for the great project!
Can you explain me the sound difference between "Baja BK Butler Tube Driver" and "BAJA Real Tube Drive"?, I'm looking for a Gilmour's sound.
Thanks and sorry for my English....

bajaman · Post by **bajaman** » 16 Sep 2008, 20:31

Hi Bajaman,
Thanks for the great project!
Can you explain me the sound difference between "Baja BK Butler Tube Driver" and "BAJA Real Tube Drive"?, I'm looking for a Gilmour's sound.
Thanks and sorry for my English....

The Tube Driver is only one small part of how David Gilmour gets his sound(s)
Cheers
bajaman

Amstel · Post by **Amstel** » 16 Sep 2008, 20:43

Oh yes I know, but the choice is not easy, can you help me? Baja BK Butler or Real Tube Drive? I can't understand the sound difference.

They've a dual power like the original Butler?
Thank you very much for your reply.

schemripper · Post by **schemripper** » 19 Sep 2008, 22:19

bajaman wrote:Hi schemripper
You could try decreasing the 2 x 47k plate load resistors - try 22k for example when using the lower plate impedance 12 AU7 type tubes - A 12AT7 might work okay in here too.
Cheers
bajaman

Hey, Bajaman, I've said it before but what a great circuit. The 12AT7 did work, but was still a bit too much.

I found a very old 12u7 (12v ex car radio valve- just like Brian May!

) in a dusty box in the very back of the workshop. I swapped in some 78/7912s to get the voltage down, and ended up with 18k for the plate load resistors- that's probably the dubious state of the valve more than anything. I think it's probably that the 12u7 is operating at its intended voltage, but it has that little bit extra sweetness over a 12au7 to my ears.

It also opens up the possibilities of running it at a regulated 12v dc, but that's too much hard work when I already have a working device

Any other little fiddles I tried didn't provide sufficient returns for the effort. The tone stack (what there is of it...

Simple and effective) was pretty much spot on.

Overall- it suits my needs, but if anyone else tries this, YMMV. Remember- a 12(a)u7 is not a gain monster. It's about 20 vs 100 for a 12ax7.

finkployd · Post by **finkployd** » 04 Jan 2009, 02:33

I'm really interested in this, but I am not confident in my ability to etch and drill the circuit boards. Is anyone selling the PCBs for this (or is Baja still selling the pedels themselves?)

Thank you

guigui1950 · Post by **guigui1950** » 13 Jan 2009, 12:04

Thanks to Bajaman who provided the PCB I have built my Baja Real Tube Driver

Here is the result, and It sounds great !

Thanks again Baja

jazcat · Post by **jazcat** » 23 Jan 2009, 08:41

Hi Bajaman, thanks for sharing your great design
I've just built one for my self, but I use a 15VAC 300mA power adapter, the result is not so good - sounds very muddy on the low notes, I tried several tubes I have (tung-sol, sovtek & EH) and also an old RCA 12at7 & also try to swap the op-amp with 4558, tl072 & opa2134, all have slightly different result on the tone & timbre, but the muddy low notes still there

Should it be any modification to fix this?

guigui1950 · Post by **guigui1950** » 23 Jan 2009, 17:29

hi jazcat

Bajaman will probably give you some help

I built myself one of this pedal and I had some sound quality problems at the beginning of tests, but it was due due to miss wiring from me.
So I would recommand that you check again all connexions, components and soldering.

I personnally use a 4558 as preamp and a 12av7 (less gain than 12ax7, it sounds good also with the 12ax7 but a bit too harsh for my taste), i just miss some bass when connected to a strat and i intend to increase some link capacitors.

hope it could help

jazcat · Post by **jazcat** » 24 Jan 2009, 03:14

guigui1950 wrote:hi jazcat

Bajaman will probably give you some help

I built myself one of this pedal and I had some sound quality problems at the beginning of tests, but it was due due to miss wiring from me.
So I would recommand that you check again all connexions, components and soldering.

I personnally use a 4558 as preamp and a 12av7 (less gain than 12ax7, it sounds good also with the 12ax7 but a bit too harsh for my taste), i just miss some bass when connected to a strat and i intend to increase some link capacitors.

hope it could help

hi guigui1950!
Thanks! i'll check all the connection & the components right away, actually I have altered few components to decrease the excessive gain (I change the 500K gain pot with a 250K + I put a 4K7 resistor in series with it so when the pot on zero position it will still have sound)
thanks !

BAJA Real Tube Drive pedal project [documentation]