2 X 12AX7 Tube pedal

[kristoffereide]

I can just say right away that we in Scandinavia ( and europe as a whole) has 240V in the wallsocket... Zeta is from Sweden, glorious Sweden.. (btw I'm from Norway)

Ahh, maybe he had to modify it form 120V to 240V outlets.

Didn't he say that he drove the tubes on 240?

[solderman]

I can just say right away that we in Scandinavia ( and europe as a whole) has 240V in the wallsocket... Zeta is from Sweden, glorious Sweden.. (btw I'm from Norway)

Ahh, maybe he had to modify it form 120V to 240V outlets.

Didn't he say that he drove the tubes on 240?

No. This one is based on 12V DC and a hi voltage switching FET/555 timer type of PS not a back to back trannie type of PS. There is a bunch of different design types based on the same basic technology.

http://www.desmith.net/NMdS/Electronics/NixiePSU.html
http://www.electricstuff.co.uk/nixpsu.html
http://amps.zugster.net/projects/subminiature Lots of sub mini info and links to really cool amp and tube stuff

//Solderman

[kristoffereide]

The tubes have about 230VDC before the anode resistor, schematic for the tubes part is based upon this one http://www.schematicheaven.com/effects/mesaboogie_v1-bottlerocket.pdf

I'll try to find some time for a soundclip soon.

/Krister

[solderman]

The tubes have about 230VDC before the anode resistor, schematic for the tubes part is based upon this one http://www.schematicheaven.com/effects/mesaboogie_v1-bottlerocket.pdf

I'll try to find some time for a soundclip soon.

/Krister

By using the Nixie type of circuit you can pump up 12v DC to over 200V DC

[zeta55]

Ok, soundclips.

http://www.zeta-sound.se/LadyEvil/Hi_gain.mp3
http://www.zeta-sound.se/LadyEvil/Lo_gain.mp3

/Krister

Grate sound but not very much differens between Hi and Lo gain??
What did you use besides the pedal??

//Solderman

Here's the stuff:
Gibson SG - LadyEvil - AmpegV2 - AmpegV10 cab - mic at close range - mixer - soundcard.

As for my private power supply There is plenty of information given in this thread of how to obtain the high voltage, I'd be happy to make a layout of one of them that would fit in a 1590BB enlosure if anyone would like to give it a go.
There's also this one: http://www.generalguitargadgets.com/index.php?option=com_content&task=view&id=136&Itemid=26

Here's the schematic for the tubes:



/Krister

[Ripthorn]

Thank you very much for the schem. I am actually planning to use a small pcb mount 12V/230V transformer, rectifier and filter caps.  Should take very little space.

[tranceracer]

Tip for those who want to boost the voltage for tub projects. The power supply is what is known as "Nixie power supply" comes from the Nixie tubes those tubes with digits in them. This is a more easy controlled one since it does not rely on zener diodes to controll the voltage. I have used it and it works grate. I did not need a fan for cooling the inductor coil at 185V.

http://www.ledsales.com.au/kits/nixie_supply.pdf

Think Rick H used it in som of his builds as well.
//Solderman 

Ahh, saw this PS kit on some other kit sites and was curious if it would be suitable for HI V tube projects.  Thanks for confirming this one too!   

[frequencycentral]

Tip for those who want to boost the voltage for tub projects. The power supply is what is known as "Nixie power supply" comes from the Nixie tubes those tubes with digits in them. This is a more easy controlled one since it does not rely on zener diodes to controll the voltage. I have used it and it works grate. I did not need a fan for cooling the inductor coil at 185V.

http://www.ledsales.com.au/kits/nixie_supply.pdf

Think Rick H used it in som of his builds as well.
//Solderman 

Ahh, saw this PS kit on some other kit sites and was curious if it would be suitable for HI V tube projects.  Thanks for confirming this one too!   

Yeah, I'm using a slightly modified version of that SMPS in my Sub Zero, it's capable of running at 230v with the right inductor, possibly higher too , as it should be possible to tweak the voltage divider which governs control pin of the 555: http://www.diystompboxes.com/smfforum/index.php?topic=74786.0

There's also a discussion of it here: http://www.diystompboxes.com/smfforum/index.php?topic=74088.0

I'm curious about zeta55's SMPS as it presumably uses a transistor oscillator in place of the NE555. Just interested in a different approach and any advantages it may have.

[KorovaMilkBar]

Wow!  That sounds great!

Bastille Day, n'est pas?

hell ya! RUSH FTW!!!!   

[enquiryband]

thanks for the schematic! now on my list of pedals to build!

[zeta55]

Here's a kind of a project file. It will be updated as I plan some changes to my circuit.
http://www.zeta-sound.se/LadyEvil/DIY-LadyEvil.rar

I'm curious about zeta55's SMPS as it presumably uses a transistor oscillator in place of the NE555. Just interested in a different approach and any advantages it may have.

Make a search for schmidt trigger oscilators, that's what I use. It has advantages as I can tune switching frequency and it's amplitude, wich has some nice advantages. 

/Krister