Full powered valve boost stage

[Narcosynthesis]

I am wandering how feasable this is to build and do...

you see a few valve powered effects, usually starved plate in a nice wee stompbox, but how about one running at full voltage sitting on top of the amp? You could easily enough setup a relay on/off (like used to switch amp channels) and it sitting on top of the amp keeps all the valves and so on out of stomping range (its going to need to be mains powered anyway)

How doable is this then? and any ideas where to look for more info on something like this? I would guess I might need a fairly large enclosure, and some form of big power supply (transformers?), one tube? or would I be wanting more, I figure a ECC83 gives you two stages, but would more be a good idea?

David

[petemoore]

How doable is this then? and any ideas where to look for more info on something like this?
  Do-able...Amp Forums have plenty of info on lethal voltage devices.
  I would guess I might need a fairly large enclosure, and some form of big power supply (transformers?), one tube?
  Power Supply is like 90% of 'it, if you've built 9v circuits...
   I figure a ECC83 gives you two stages, but would more be a good idea?
  It depends on what you want, if you want preamp tube distortion, this will provide some, you have some in your amp...etc. whether you're using this to drive the amp harder to make it distort or using 'internal distortion' [if the amp is real clean..using the preamp to make all or most of the distortion] should help you decide on what to build.
 

[fikri]

Yep, the most confusing part is when setting up a good layout. If you planned carefully, you will have a very good result (and looks too !) I have done some tube booster, overdrive, or even full distortion, if you run a traditional transformer, sure it will eat up some more space. Use a toroidal or set up a back to back transformer if you want to save some space.

[swt]

there are commercial available ones. Hotbox from matchless. And also soldano pedals, etc. it's not difficult to design one as it's just a tube pre...

[Narcosynthesis]

Half of it is for the fun and the project, and taking the overly anal tone geek/valve loving to the next step (regardless of being happy enough with my Marshall BB2 for boosts...) and to see what the results would be.

so really I am just looking at the preamp of an amp, plus power supply to feed the valve. I was thinking of a clean boost for now to drive the amp a bit harder (can always do an improved version later)

What amps should I look at for a nice simple preamp?

David

[swt]

maybe my post was misunderstood...i was not suggesting to buy those pedals...i have the schems if you want. i meant that those are clever designs that work the way you want. the hotbox has 2 tubes, 250volt B+, a clean section that can used as a boost, and a crunch section that is vox derived. I can point or design other pedals as well...i love tubes, and also build tube amps.