Tube Driver question

[JimRayden]

I have built a Tube Driver with an external tube socket where the tube stands on the top of the box. I was wondering, does a plastic box take the heat from the tube if I placed the tube inside it? If yes, then would the box need to be ventilated?

I'm on a kind of a budget and I don't have the tools to work with a metal box but I don't want my stompbox to start melting in the middle of a gig also.

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Jim

[GreenEye]

Can you post a pic of it?  I bet it looks neat with the tube mounted like that.

[smashinator]

I'm guessing whether the plastic will take it or not depends entirely on what kind of plastic it is.  The plastic spatula in my kitchen seems to be able to take a lot of heat...  :wink:

You can always put a huge number of ventilation holes if you're worried about the plastic melting.  Paul Marossy built a Shaka Tube in a metal box with no ventilation. (//www.diyguitarist.com)

I'm curious about what you're using to put holes in the plastic box, if you can't afford to drill an aluminum box.  Aluminum is an easy material to drill, so it doesn't take a lot.

[JimRayden]

Oh yea... it's not exactly a "stompbox" but it screams and that's what matters. I also didn't spend money on unnecessary stuff like knobs.




And I'm using a plastic box for the next project to make it look cooler. It's a blue transparent box and I'm gonna call it Bluey.
Either that or a red transparent.

The pics:
blue: http://www.elfa.se/images/highres/h4371.jpg
red: http://www.elfa.se/images/highres/h4372.jpg

They make them lots of sizes and that won't be a prob.

And I can get the stuff needed for working with metal boxes afterall.

So, I need to decide.

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Jimbo

[Dirk_Hendrik]

The tubedriver is a low voltage circuit. Most of the heat in tubes comes from anode voltge dissipation. When this voltage is low the tube will not get more than lukewarm and can be touched without the risk of burning oneselves. Therefore heat dissipation is not really important.

Let me refer to one of my projects of a few months ago (time for something new to publish)
http://diystompboxes.com/sboxforum/viewtopic.php?t=24489&highlight=tubeoverdrive

In this ptroject there's absolutely no need for ventilation ans the box just becomes a little warm.

[JimRayden]

Thanks, I'll go with bluey then. I'll try to ventilate it too (just in case).

edit: I love self-burnt PCB's. Really cool looking pedal you've got there!

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Jimbo

[GreenEye]

I like the tube on top.  I'd like to do one like that, but put a cool little wire cage over the tube.

[JimRayden]

Yeah, mine was made in kind of a rush but it looks cool. I thought of a wire cage too but decided to leave that kind of stuff for another build as it was my first tube pedal.

By the way, if you put the 9-volt transformer on the top also, it almost looks like a tube amp.

Me love that transparent box. Wich looks better, red or blue?

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Jimbo

[JimRayden]

One more question.

I read that the 12AU7 gives a smoother breakup and such. What's the difference exactly? Can I still achieve overdriven sounds with single coil pickups with AU?

EDIT: Ok, I'm choosing the transformer now. anyone know how many VA it should be?

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Jimbo

[JimRayden]

Sorry about bringing the topic up from the 3rd page but I didn't want to make another one because of that small question.

Can anyone tell me what transformer should I use for the GGG's Tube Driver circuit? 12 volts and how many amps/VA?

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Jimbo

[JimRayden]

I'm pushing the topic up until I get an answer of some kind.

Check the previous post.

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Jimbo

[Paul Marossy]

A 12VAC, 200mA wall wart would work. You should be able to get some distortion out of a 12AU7 with single coils. It'll probably sound more bluesy than anything else. Most of the clipping happens in the opamp section so as long as the input is strong enough in amplitude, it should give you some clipping still.

[JimRayden]

Thanks.

This topic can now go to the graveyard of ditched topics on the page 2...  :twisted:

Ok, anyway, thanks


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Jimbo

[Paul Marossy]

No problem.