Question about 12AX7 tube driven OD/Distortion/Amp

[Govmnt_Lacky]

I am looking into possibly building up a 12AX7 based effect. I have seen the Shaka but I am really interested in building something else. Maybe a pre-amp or another OD/Distortion.

This is a solicitation for suggestions, comments, and links to projects.

Thanks 

[anchovie]

Do you feel comfortable/confident about working with voltages that could kill you?

[Govmnt_Lacky]

Do you feel comfortable/confident about working with voltages that could kill you?

I don't know.... Can this thing put out 200A at 400Hz? If not then I think I will be OK.

Any ideas?

[Govmnt_Lacky]

The inconvenient BUMP 

Any ideas for a tube-based OD/Distortion using 12AX7 tubes? I have 3 on hand to play with.

[merlinb]

If you're willing to build a small, high-voltage supply (a la Real McTube), then you could feasibly copy just about any existing valve preamp schematic you care to mention.

[davidallancole]

Govmnt_Lacky, I get a feeling from your reply you are in the electrical industry?  Just remember that there is voltages here in tube circuitry that can kill you.  It doesn't take much.

[Govmnt_Lacky]

If you're willing to build a small, high-voltage supply (a la Real McTube), then you could feasibly copy just about any existing valve preamp schematic you care to mention.

Thanks. Do you have any links to PCB layouts. I know of the Shaka but not many others. I dont do vero or perf but if you know and PCB layouts then that would be great!

Govmnt_Lacky, I get a feeling from your reply you are in the electrical industry?  Just remember that there is voltages here in tube circuitry that can kill you.  It doesn't take much.

I am well aware of this. I will take the necessary precautions.

[Govmnt_Lacky]

Ok... Now that I have been WELL informed about the dangers of working with HIGH VOLTAGE tube-based projects, bring on the suggestions and layout links! 

[defaced]

Merlin already gave you the best answer.  The question is more not what's available, but what are you after?  Once there's a target on the wall we can start throwing darts at it.  What kind of music do you play?  What kind of amp is this going into?  All of this stuff will help you get meaningful suggestions.  But less that, I think you should use all three tubes and build a Soldano SLO style high gain circuit.  Why?  Because it's what I just finished building. 

[Govmnt_Lacky]

But less that, I think you should use all three tubes and build a Soldano SLO style high gain circuit.  Why?  Because it's what I just finished building. 

What is this High Gain device that you speak of? [typed with eyebrow raised]
You have peaked my interest since I am definitely interested in some high gain crunch!
Could you provide details or a layout? PCB perhaps??

[defaced]

Doing homework on this one is easy.  I'll leave all that fun stuff to you.  All of the information is out there if you use Google, including my turret layout for the OD channel only.  All you want to do is Clone the SLO. 

[tubelectron]

Hi Govmnt_Lacky,

Let's suppose you are OK with 250V plate voltage and want to stay with a simple design, with only one 12AX7.

For a Hi-gain overdrive pedal, the Westbury W-20 works well (I have one, mint-condition, made in 1980) :



For a subtle-to-vintage-to-medium-gain overdrive, my tubelectron overdrive II is worth to try :



In both case, I would now recommend a DC heating of the 12AX7, for a better hum quietness.

A+!

[zambo]

I got to tell ya, I have been having a LOT of fun inventing or butchering and hacking designs on my own. If you just look at most pre amp schematics they are all very similar. Just take three tube sockets and cascade them together running 100 b+ volts with 1 meg pots between stages and a 1.5 cathode resistor to start. See where that goes and have fun tweeking it over about 3 weeks. Who knows, maybe your design is the next one we will all want to clone..