DIY Tube Pedal?

[bennerman]

Anyone know how I would go about building the simplest possible tube overdrive pedal?

I'm looking at a tube amp that is very good for the money, but doesn't quite have as much gain as people would like, so I want to use the pedal on top of that.

I don't think it would need any controls, because if the amp weren't cutting it, I'd just turn the amp down to a cleaner volume level, engage the pedal at full power, and then dial-in my distortion using the amp itself.

So theoretically, it'd just be the input/output plugs, the tube, the power-supply (or battery pack), and any other smaller incidentals.

Thoughts?

 

[bostjan]

Yes.

Beavis audio has a schematic for a tube boost using, IIRC, a 12AT7 (maybe 12AU7) and a 9V battery.

 

[bennerman]

Yes.

Beavis audio has a schematic for a tube boost using, IIRC, a 12AT7 (maybe 12AU7) and a 9V battery.

Ooooh, nice. Know if there are any step-by-step guides, instead of just a wiring diagram. Haven't dealt with those since grade 9 XD

 

[Vostre Roy]

Grind Customs FX

At the bottom of the page, there's a JCM800 preamp in pedal form, with the tutorial how to build it and the power supply to make it work right under it.

Can't think of any other DIY tube pedals as they are tricky to power since tubes needs high voltage to work and pedals usually don't work on such high power.

 

[bennerman]

Grind Customs FX

At the bottom of the page, there's a JCM800 preamp in pedal form, with the tutorial how to build it and the power supply to make it work right under it.

Can't think of any other DIY tube pedals as they are tricky to power since tubes needs high voltage to work and pedals usually don't work on such high power.

supposedly the low voltage is better for distortion because they have to work a lot harder to run, giving higher distortion and minimum boost. or so I've heard, anyways

 

[InfestedRabite]

I have a tube OD pedal like this, use it for my coil-split tone. tho it does have Gain/Tone/Volume controls, which i quite appreciate

it was built by a local guy here but I could ask him when I see him what specs it was built off?

 

[Vostre Roy]

supposedly the low voltage is better for distortion because they have to work a lot harder to run, giving higher distortion and minimum boost. or so I've heard, anyways

Not what I meant

A tube plate require from 120v to 250v DC to run properly. Either you run it hot or cold will affect the distortion, but in any way it will be high voltage, or at least higher voltage than an usual pedal will see.

A tube pedal shouldn't be your first DIY electronic project by the way, its a bit trickier than it might seems and you will play with high voltage stuff. My 2c

 

[bennerman]

Not what I meant

A tube plate require from 120v to 250v DC to run properly. Either you run it hot or cold will affect the distortion, but in any way it will be high voltage, or at least higher voltage than an usual pedal will see.

A tube pedal shouldn't be your first DIY electronic project by the way, its a bit trickier than it might seems and you will play with high voltage stuff. My 2c

Way ahead of you. My first project was already gunna be an emergency LED lantern

 

[bostjan]

supposedly the low voltage is better for distortion because they have to work a lot harder to run, giving higher distortion and minimum boost. or so I've heard, anyways

This is true, if I understand you correctly.

The lower the voltage, the less headroom the tube has to do its amplification thing. Lower headroom means clipping at lower input levels.

However, the magic thing is that the tube still has to operate. A 12AX7 has a higher voltage requirement, but it just won't work at 9VDC.

Also, too much clipping, and the sound loses all musical value.

 

[bennerman]

This is true, if I understand you correctly.

The lower the voltage, the less headroom the tube has to do its amplification thing. Lower headroom means clipping at lower input levels.

However, the magic thing is that the tube still has to operate. A 12AX7 has a higher voltage requirement, but it just won't work at 9VDC.

Also, too much clipping, and the sound loses all musical value.

Yeah, supposedly you are supposed to use a 12au7

 

[neotronic]

this might be a good start: http://miaudio.com/wordpress/wp-content/uploads/2013/11/12AU7-6111_Valve_Caster_Summary_Rev002.pdf

and using 9 or 12V wallwart should be pretty safe.