Tube Distortion (Project)

[Perkla]

I have been thinking about building a tube distortion pedal... would it be possible to build something that sounds like this one.. ? 

http://www.youtube.com/watch?v=R1dazYO6ntU


The sound is AWESOME... i really like it..

[defaced]

Not to point out the obvious, but that person did, so yes, it's possible.  

Now, being a high gain tube amp builder, I'll make some comments/observations.  With four triodes, there is probably something else in there either generating distortion than a tube stage, or they are using SS devices in the signal chain, maybe to drive the tone stack or as the first gain stage (which usually isn't distorted, so SS devices are cool here).  Or it's overdriving the the amp behind it, like clipping the return stage of the 5150.  That is way more distortion than what you'd get out of three cascaded stages and a cathode follower driven tone stack.  Also, it sounds like a very tight gain sound, which I would associate with typical preamp voltages of 300-350v range for this sort of preamp.  

[FiveseveN]

Maybe he used a MOSFET cathode follower or the tone stack is buffered in some other way (e.g. an active EQ).

[merlinb]

I would associate with typical preamp voltages of 300-350v range for this sort of preamp.  

It says on the description that it uses 'full range voltage'.

There's a good chance that it doesn't use any buffers at all. Four cascaded gain stages with a tone stack jammed in between would easily develope those levels of overdrive.

[Perkla]

So... where is it possible to find a pcb layout or parts list or something like that... to be able to build a pedal like this.. ??

[gtudoran]

Why don't you try this for a start: http://www.diystompboxes.com/smfforum/index.php?topic=89795.0

Best regards,
Gabriel Tudoran
Analog Sound

[Perkla]

I would like to build a heavy tube distortion pedal.. not a clean pedal or something like that....

I belive there is several issues to deal with to get distorted sound out of a tube pedal... i know there is a few pedals that is tube distortion pedals... maybe could be a good start to build and then try to modd a little and see how much gain its possible to get... !?

[Renegadrian]

4 triodes can be very aggressive...mind that the pedal in the video is running at full voltage, also he uses the a guitar with emg's so the output is quite high. If you're after some gain, I'd say give my TUBE STAR a try, it's just one tube and it works good with a simple multiplier at +-50v. it'd easily fit a b case.

[Perkla]

I have EMG pickups in a few guitars that i have... and i also have some other passive pickups with high output...

Is there a PCB layout avalible for the tube distortion u are talking about.. ?

[DonB]

I'd also be very interested in building something along these lines. It has a great sound.

Anyone have any idea how to implement this to get that amount of gain?

[petemoore]

  Yep, nothing you can do that can't be done !
   Interesting clip, choice of circuit etc.
    If we knew the circuit it'd be fairly easy to clone it, we dont'.
  Buying it is certainly the easy way to get more familiar with some of it.
   The other parts are well chosen and the amalgum rig/record methods produced fine metal clips.
  Buying it is the simple way to avoid extensive HV tweeking.
   That kind of tone needs books thrown at 'it' to get 'it' to do 'it'.
    I'd use speaker/cabinet to get compression/suspension tone elements...the old school way using scale-proportioned output tube amplifier [or old school tube amp/speaker cab], choosing components for these positions to make pedal sound has proven critical in my recording and or distortion endeavors.   
  Building an unknown 'it': I'd start with a pen 'n paper or computer enhanced schematic drawing program, then move to chassis layout design...
  ..while de-B+ing the PS on the second prototype [I would need at least two units so they could be 'raced' to determine a winner, spare is handy etc., second one always seems to be different than first one] for the 17th time [I'd probably try 'stepped plate voltages'] and throw anything else in there...because a distortion project is it.
  Anything else could include Jfet at 'LV'...this voltage would be easier to 'tune'...or Mosfet instead of cathode follower, clipping diodes...
   Probably I'd build the tube section then see what type of harmonic contents and swing voltages throw the distortion into smooth/thick/budgey like that.
  Considering everything else that could have been thrown in the pot [ie to make/record sound], the price of the pedal itself seems quite reasonable.
   Attempting to replicate something close to that would probably be...quite an adventure with dangers.
  Many of the questions would need to be adressed, and drawing up a plan'd be imperative.

[DonB]

Buying the pedal isnt the best option at present...As from what i have been reading, they are very dodgy to deal with.

[tubelectron]

Hi All,

Should I recommend this vintage tube pedal (1978-1982) :




Here is it's schematic (Thanks to R.G. Keen - verified OK on my unit pictured above).
As you can see, it's a relatively simple design unit :



And it works well, very consistent tone, from subtle bluesy touch-sensitive to high gain solid rock full of overtones. To give a comparison, the maximum gain is similar to what you would have with a vintage RAT LM308 at the maximum, with the filter at 3:00. One drawback on the original unit : the signal to noise ratio is only average.

A+!

[DonB]

just had a thought. Could you possible incorporate the dr boogie gain stages with the tube to get better gain? also interested in the boogie... but i do prefer more british hi gain.