tube distortion pedal

[black_labb]

hi guys, ive been thinking of making myself a distortion pedal and was wondering if it was possible to use an actual tube to create the distortion (ie volume through the tube to get the right level of distortion, and then another pit after to get a suitable volume)

now, is this easy to do, or is doing this basically making a simple amp.

to overdrive the tube would i need a certain voltage, or do you overdrive the tube in another manner? (i think its the voltage, but thought id ask just incase)

if it is the voltage, is it possible to get a tube that is small enough to overdrive at low enough levels to use with a 9v battery or a similar thing (maybe a wall attachments to get the right power input) and is small enough that it can be then be toned down using a pot to a output level that isnt too much different from passive guitar pickups? (basically something that would work fine on my amp)

im not that knowledgeable about electronics, but ill look into it if it is possible.

thanks for any help

[nico.verduin]

There is a guy in Holland "Richard Nijboer" who has designed a combination of Opamps and a tube for a Tube overdrive including a schematic and a youtube video. see: http://www.gitaarnet.nl/forum/showthread.php?t=92749
It is a 12V DC version. Although the language is dutch it might still be usefull info.

[black_labb]

thats cool, it was what i was thinking, it looks a bit more complicated than what i was thinking, but its doable i guess, ill need to spend a bit of time figuring it out though.

what are the nessesary elements to do this? im thinking input into tube, wire a pot to determine the drive on the tube, then a master volume to determine the output of the system/bring the output down after amplifying it

i dont understand the electronics much, and id like to know what im overlooking, unfortunately i dont know dutch.

thanks for the reply,



ps. i accidentally put this in this section, if someone wants to move it that would be good, thanks,

[Enzo]

How big you want the pedal?

Go to New Sensor and check out the tube effect pedals by Electroharmonix. I suppose EH has its own web site too. Ther are some microminiature tubes that run on lower voltage and could be designed into somethign. SOme of these have wires sticking out of the glass, and you solder them in. They look like a large NE2 neon bulb. There are some not quite so tiny tubes that do use sockets - or solder - like maybe 3/8" diameter. I thin these tubes were designed for applications like car radios, so some of them ran on [pretty low B+. SOme have 6v heaters and some 1.5v, and maybe other levels.

I've been wanting to make something out of these things for a long time, but never get around to it.

[Amp Kat]

Are you talking about Nuvistors Enzo ? I have some sockets and I think a few of the Nuvistors I'd be happy to send you if I can find them. I messed around with them a tad at Presonus but got rerouted to another project. They do seem like a prime candidate for this and I think the heater voltage is around 1-1/2 to 2 volts. Let me know

[Don Symes]

Since your experience level is pretty minimal, may I suggest a kit?

Ted Weber has this MASS pedal that should be about what you want.

[Amp Kat]

Hey Don, just curious, have you heard this pedal and what voicing amp would you think it resembles most ?

[Don Symes]

Hey Don, just curious, have you heard this pedal and what voicing amp would you think it resembles most ?

I haven't even seen one in person. What I do know is that Ted makes a really high-quality kit, and that something small like this is a great introduction.

Since you actually build it, and know how it goes together, you can also look around for other preamp and OD circuits to try to mod into the Mass pedal and try them out at fairly low expense and risk of killing something else expensive.

--- Oh! - thought I was answering black labb - sorry if I offended.

Hope this helps!

[Enzo]

No KB, not Nuvistors. Those are little metal things that look a lot like transistors. Look up 5975 or 6021. I don't think RCA got into these, but the GE book is full of them. If you have the GE book, tube outline shapes with numbers starting with a 2 or a 3, like 2-1, 3-6. Tiny little glass tubes with wire leads trailing out. Like an oversize NE2 lamp, if the tube has 5 leads, they will be in a row across the bottom.

[black_labb]

thanks alot, might look into that kit, seems a bit pricey, i know it will work though.

using that schematic and making it myself isnt a bad option either. i live in australia which would make it a bit annoying to have it shipped here, when i can just use the schematics and figure it out myself...


are output transformers like that hard to come by?

ive read that you can wind them yourself on jon tirones website. im not too knowledgeable about electronics but i like to learn things, and may havel alot of free time coming up. i have a lathe setup for winding pickups, would winding a transformer be hard to do?

im not too worried about the size of the pedal either.

i keep thinking if im going to go that far i might aswell make a whole amp, and if i did that id make it so that i could easily add circuits to it to make it more versatile

sorry for being so long winded, im just wondering if i should start with a simple distortion stomp box, and then move onto making an amp once i feel comfortable with the electronics, because it seems like i would be just making a small amp, to plug into my current amp, when it wouldnt be much harder to make the whole thing myself, just increase the size of the thing. it wasnt too long ago that i didnt understand the electronics inside a guitar, but it seemed overnight that i thought i could wire the guitar im doing at the moment without using any outside references for knowledge, and its not standard wiring. not that the electronics are hard, i just find i can learn things easily and i dont think ill be long before i can do a amp.

[Rob Mercure]

What Enzo is referring to are "subminiature" tubes most of which were produced just prior to practical transistor production. While a few made it into consumer hands - in particular hearing aids and some portable radios - the majority were produced or designed by Raytheon for use in missile proximity fuses and tube computers. Being industrial/military products these were "high reliability" tubes usually with a 10,000 hour claimed life. Sylvania was Raytheon's primary design competitor with, among other designs, an 8 pin radial design while Raytheon used the "flat press" design Enzo described.

These little bottles are neat with truly thrifty heater requirements - 1.4 V @ 20 mA in some cases - and pretty low plate current requirements. I've been doing some experimenting with 1W5s in triode connection for tube "stomp boxes" with the only issue being able to find sufficiently small "B" batteries. As most of the signal level tubes work well on 35+ volts putting a bunch of 9 volt batteries in series isn't that much problem. Unfortunately most of the power pentodes and BPTs work best with at least a 90 V B supply which has been my hold up in creating a "Herzog" battery pedal.

Oh, in addition to the subminiatures there were scads of low heater/B voltage seven and nine pin miniature tubes made for the portable radio civilian market and I've done some fooling around with 3V4s and such. And let us not forget the 12VDC B supply "space charge" tubes designed to drive a "door knob" output transistor in automobile radios during that transition period when transistors internal capacitance limited their use to AF and below. These tubes run quite well with 12V on both the A and B supply but they are "current hogs" while producing the space charge and only suitable, IMHO, for line supplied power supplies. But you can get the 12K5 to put out about 100 mW in PP to give you a nice little all tube stomp box.

And almost all of the tubes I've described above - with some notable exceptions such as the 1L5 - are truly dirt cheap allowing one to make a "lifetime" purchase of an interesting valve as these bottles were never made in quantity in the first place and slowly "eroding" away over time.

Rob

[Guitarist]

the dutch pedal

Here's a PDF from that site. I thought to spare you sleuthing through 54 pages.
I'm pretty impressed with it and would love to have the PC board somehow. I'm sure there's huge possiblities in combining chips and tubes for guitar. I'm thinking of throwing some Bog Muff circuity over a tube myself.

What I did do recently was jam in a couple diodes (grid to ground) in a tube amp which really took it over the top. Noisy though.

I've also made a minitube cord inspired by the fetplug and am just working at the PS for it. Got a couple of 23a camera batties from the $ store. How can I get .75 V from an AA?

[Regis]

The late Fred Nachbaur designed a real cool tube overdrive that i want to build one day, check it out here.

[Guitarist]

It would be nice to have a small transformer that would give only 6.3 V@600mA and 200 or so volts. And is quiet to fit in the pedal box. I had to rewire a 2 x 12ax7 pedal to have the 12V transformer outside as it hummed too much. That EH toroid works great. The new Seymour Duncan pedal is likely going be the ultimate and in line with what this thread is shooting for.
Love those pickups though my Bill Lawrence PUPs are pretty deadly too.

Would a simple voltage divider work to power the heaters on these mini tubes eg 512ax from a AA or would that draw too much extra current?

Maybe I should just stick to playing guitar...

[frank.clarke]

The late Fred Nachbaur designed a real cool tube overdrive that i want to build one day, check it out here.

Late? I'm sorry to hear that, I got a few emails from him. I built a McTube, and then put a voltage doubler on it. Good to have instant tube gain overkill.