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DIY Stompboxes => Building your own stompbox => Topic started by: Somicide on December 18, 2003, 02:39:10 PM

Title: Trans' or tubes, hmm i wonder...
Post by: Somicide on December 18, 2003, 02:39:10 PM
I thought of this, as a method of generating a tube sound in a SS amp.  Now:

would it be possible to use tubes in lieu of transistors in a ckt (like the Big Muff, for example)?  I'd love to hear how that'd work, if possible, probably need some sort of massive proprietary pwr supply though or something.
Title: Trans' or tubes, hmm i wonder...
Post by: Ansil on December 18, 2003, 08:31:04 PM
i haven't tried the bigmuff but i used to have posted a tube ts9 and a tube guvnor
Title: Trans' or tubes, hmm i wonder...
Post by: Jason Stout on December 18, 2003, 08:45:07 PM
Quotei haven't tried the bigmuff but i used to have posted a tube ts9 and a tube guvnor
Ansil
Did you make a tube opamp?
Title: Trans' or tubes, hmm i wonder...
Post by: Ansil on December 18, 2003, 08:56:00 PM
no i designed the  gain and freq to be similar as i could get to the previous described pedals.


i guess icould if you wanted me to design one.

although personally iwould use subminiature declassified military tubes. since you need so many
Title: Trans' or tubes, hmm i wonder...
Post by: Somicide on December 20, 2003, 01:18:47 AM
then i'd just have to make a huuuge casing, with tube sockets.  ON another note, don't tubes have like 6, um, metal thingies (the term has escaped me) contacts or whatever, while transistors only have 3?  how would i work that?
Title: Trans' or tubes, hmm i wonder...
Post by: Brian Marshall on December 20, 2003, 01:49:21 AM
that is because each tube has 2 stages

plus it has to heat the filament.

I dont know a thing about tubes though.  From what i do under stand the opperate more like fets that bipolars
Title: Trans' or tubes, hmm i wonder...
Post by: Jered on December 20, 2003, 02:02:27 AM
Here you go, tube op amps
http://www.triodeel.com/images/gaprk2w1.jpg
http://www.triodeel.com/images/gaprk2w2.jpg

  and if you scroll about 2/3 down this page you will see the whole George Philbrick Tube OP Amp manual.
http://www.angelfire.com/electronic/epeasant/circuits/circuits.html

 Enjoy,  Jered
Title: Trans' or tubes, hmm i wonder...
Post by: Peter Snowberg on December 20, 2003, 02:30:24 AM
Quote from: Brian MarshallFrom what i do under stand the operate more like fets that bipolars
Tubes are voltage controlled devices and work like depletion mode JFETs, such as the 2N5457, J201, and MPF102. BJTs are current controlled devices.

You can use tubes at low voltages, but I don't know how they would respond. I've built a couple of distortions than ran from 12 volts, but that was to abuse the signal. :)

There was a whole family of low voltage tubes, but the B+ was generally maxed out at 60 to 90 volts.

Take care,
-Peter
Title: Trans' or tubes, hmm i wonder...
Post by: Chill on December 20, 2003, 01:33:48 PM
I think the old Chandler/ BK Butler/ Tubeworks Real Tube Overdrive ran the tubes at 12V, although the schematic for that was a 4 knob and the ones I've seen are 5 knob.  The Real McTube, Matchless Hotbox, and Ibanez Tube King are three other tube effects which come to mind.

You could also take your basic Marshall JCM800 2 tube preamp and put it in a box, though you may need some fancy switching to keep your input and output away from each other...and you'll need to rectify and filter the mains to get a smooth ~240-300V for the supply.  Though it might work with a 120V supply with some parts value tweaking.  Less voltage = less headroom = more clipping.

And yep, 12ax7's have 9 pins, 1-2-3 and 6-7-8 are the two triodes, 4,5, and 9 are the filament pins.  Check out Aiken's Common Cathode design article (http://www.aikenamps.com/CommonCathode.htm) for more on how to tweak the tube stages.[/url]
Title: Trans' or tubes, hmm i wonder...
Post by: Elektrojänis on December 20, 2003, 04:55:15 PM
Quote from: JeredHere you go, tube op amps
http://www.triodeel.com/images/gaprk2w1.jpg
http://www.triodeel.com/images/gaprk2w2.jpg

That's freaky. How about that and some rectifier tubes (or whatever... I don't know anything about tubes) for diodes for TS or Rat or maybe Shaka Braddah clipping stage.
Title: Trans' or tubes, hmm i wonder...
Post by: Ansil on December 20, 2003, 05:54:23 PM
i did a tube version of the ts9
Title: Trans' or tubes, hmm i wonder...
Post by: Elektrojänis on December 20, 2003, 07:02:30 PM
Quote from: Ansili did a tube version of the ts9

Any sound clips?