Interesting Mod: a Boss SD-1 with a 12AX7 in it.

[puretube]

12volts?? 6.3v could do it, if you run the filaments in parallel instead of series..

Claus H

the tube "can do" the diode-thing down to 2V or even less at the filaments...

[petemoore]

Ok tubes as clipping diodes...
 Would that sound like Si Ge's or something else entirely.
 what would be the clipping threshold?
 Think there's any 'scoped' or percieved advantage to using a tube to clip signal tops and bottoms?
 it makes sense...at least the tube is being used for something other than it's 'warm glow'...!!!

[bobbletrox]

the tube "can do" the diode-thing down to 2V or even less at the filaments...

Ahh...I see.  This is getting interesting.  I'm going to have to read up on this!  Your Tube-Fuzz and Tube-Distortion use tubes for clipping diodes, don't they?

Imagine a tube mod for a big muff.  There's plenty of room in those enclosures!

[bobbletrox]

May I also add that I'm interested in this to satisfy my curiosity.  I'm in no way under the impression that tubes will give my tone super mojo    They just sound like an interesting change from the usual LED/Germanium/Si choices.

[Ben N]

And no socket--there's stuff soldered right on the pins--now THAT'S what I call point-to-point!

[sir_modulus]

And no socket--there's stuff soldered right on the pins--now THAT'S what I call point-to-point!

Thats hard soldering. To much heat, and you'll desolder it from the inside.

[Regan]

The way I use to get past having to use a tube socket(if I'm out of that style) is I have a bunch of jumpers made with the sockets out of surplus rs232 jacks(serial port). I have a few of these kicking around so since it hasn't been soldered to yet, you can pop them apart then just solder wires to the sockets, heatshrink and your set. You may have to crimp the socket a bit for a tighter fit on the tube pin.
Regan

[puretube]

...Your Tube-Fuzz and Tube-Distortion use tubes for clipping diodes, don't they?....

only the Tube-Fuzz (TM),
but in a different topology...
- the diodes need to be able to handle
well over 150Vpp signals -

[Phorhas]

Looks like it could be used as a Tube-Pedal-ripoff... think about it...a cheap clipper with a glowing tube in it... I can see it now: "add the warmth of tube to youe rig"...

$25 worth of  and a $400 price tag

[Hairston]

Ya know what guys, I'd probably do this project for the sheer novelty of it. Not that I would ever really use it (unless it sounded really great). I'd just do it so I could say "Yeah man, I modded an SD-1 to incorporate a tube in it's circuit. What the h*ll did you do today?"

...and the n00bz would be like: "WHAT?!" :shock:

Heh...

-HB

[sir_modulus]

isn't that what we're all doing now? It's drawn so much attention, yet it's so simple. I don't see why I can't run up any of these kinds of ideas.

[bobbletrox]

I've been intrigued with the idea of using tubes as clipping diodes for a while, but never persued it much because I thought it'd be really complicated.   Seeing someone implement it as a mod to a mass produced pedal blew my mind because it must be reletively simple...yet I still can't work it out!  lol.

The more simple tube circuits we have, the easier it will be for people to move into other tube-based circuits.  It reduces the learning curve, because let's face it, going from solid-state effects to tube-based effects is daunting.  Every little bit of experience helps, and something as simple as adding a tube for a clipping diode builds confidence for trying something bigger.

[Hal]

you could use one of those 20v 9v batteries to power it :-D

I posted a thread a while back about using tubes to clip.  I think some smart conclusions were drawn....dont totally remmeber though...

[puretube]

...The more simple tube circuits we have, the easier it will be for people to move into other tube-based circuits.  It reduces the learning curve, because let's face it, going from solid-state effects to tube-based effects is daunting.  Every little bit of experience helps, and something as simple as adding a tube for a clipping diode builds confidence for trying something bigger.

that`s the right attitude, here, imho!

One shouldn`t forget, that the SD-1 is a box that imitates the behaviour
of a driven tube-amp through its topology
- just replacing the solidstate by a "real" diode will not automatically
turn it into a real tube amp -

but it might add another nuance to the Ge/Si/LED farm...

[markr04]

reminds me a little of this:
http://www.geofex.com/FX_images/realtube.jpg :wink:

omg... Tomboy... LOL! The pic at the link had me rolling on the floor! Thank you!!

[paulyy]

I know this thread is abit old but I just tryed this mod on a SD1 with a 12au7 tube and got great results. Its pretty easy to do and one tube can be used as 2 diodes or 1 diode. Im rehousing my SD1 so installing tube will be easy to do. Ill post a link when I get done with the pedal someday.

[Joe Hart]

How does the tube sound in it? How is it different? Any sound clips? Thanks!!
-Joe Hart

[MetalGod]

since space is tight and the 12AX7 is only being used as a diode, why not use those old 7-pin tube diodes like the 5726??? - dirt cheap, NOS quality, 6.3v heaters that will work off DC, AND they're almost half the size of a 12AX7.  its a win win solution.

[paulyy]

How does the tube sound in it? How is it different? Any sound clips? Thanks!!
-Joe Hart

Sounds kinda like the valvcaster but the gain is much more smoother when all the way up. Its got a good sound but it can be over powering at times. I think a resister or capasitor acoss the + and - will tame it a little. Dont know, still expermenting with it. As far as sound clips, Ill post it on youtube and and ppost the link. I just need to find time to finish the pedal.

[Renegadrian]

I don't know, I am not a fan of hybrid circuits...I don't want opamps with tubes in the same box. But yeah that's me!