TUBE - another 12AU7 booster from japan

[Renegadrian]

Hey guys, found this one browsing around...Guess I'll build it someday, it's so damn easy!!!
Dunno who created this one, but I guess I'd like to share...

[anchovie]

What kind of site is this from? My work internet is blocking it on the grounds of nudity! 

[Renegadrian]

Really?^! It's just another free image hosting site...

[petemoore]

  Looks like maybe a novel power supply for the plate...
  Can't read any part types or values though.

[punkin]

Thanks Renegadrian!

[Renegadrian]

  Looks like maybe a novel power supply for the plate...
  Can't read any part types or values though.

[Renegadrian]

Thanks Renegadrian!

I'll build it next year! (well, in january, I mean!!!) Happy TUBE Xmas!!!

[Paul Marossy]

Wow, that is simple. I wonder how it sounds... 

[frequencycentral]

As it's basically the first stage of a Valvecaster (but without an input cap) and a higher value ouput cap it's not going to be that different. Just a mild boost, maybe a bit more bass getting through. Nice example of power supply filtering though.

[kurtlives]

As it's basically the first stage of a Valvecaster (but without an input cap) and a higher value ouput cap it's not going to be that different. Just a mild boost, maybe a bit more bass getting through. Nice example of power supply filtering though.

That and with the 1K in series with the pot on the cathode you'll never get a mu-follower. Will be a bit cleaner.

[puretube]

Does the pot crackle?
Can I use a 0.82µF/630V output-cap or will the midz be less transparent then?
Will a charge-pump to up the plate-voltage to 15V help increasing the headroom,
when I add a pulldown-resistor to the output?

Aren`t boosterz from china cheeper?

[frequencycentral]

As it's basically the first stage of a Valvecaster (but without an input cap) and a higher value ouput cap it's not going to be that different. Just a mild boost, maybe a bit more bass getting through. Nice example of power supply filtering though.

That and with the 1K in series with the pot on the cathode you'll never get a mu-follower. Will be a bit cleaner.

My Valvecaster's already got a 1K8 resistor in series with the pot - stops the 'thunk' when you max the gain pot.

[DUY1337GUITAR]

You're gonna build that on New Year's and forget about my birthday?! FINE!

I'd like to hear what it sounds like, I hope you get some clips up soon

[sean k]

You'd get away with a 100V cap on the plate easy easy easy, anything above 10V and I'm sorry but it seems rather a waste of a tube to be used as is and to disregard the other triode as well

Heck, you could be playing with high voltage!

[DUY1337GUITAR]

You'd get away with a 100V cap on the plate easy easy easy, anything above 10V and I'm sorry but it seems rather a waste of a tube to be used as is and to disregard the other triode as well

Heck, you could be playing with high voltage!

I'm not that knowledgeable about tubes, yet.  So higher plate voltage gives more headroom and/or rounder overdrive and/or volume and/or....  Or does it depend on the overall circuit?

[Renegadrian]

About the disregard the other triode - Yeah I know it's a pity to leave it unused - At the same time I have developed a one triode booster myself (I never shared it, but I think I will, after some more experiments). Maybe it can be a good field for experiments, the one triode booster field. I have seen also some one triode subminis for cheap...

[Ripthorn]

You'd get away with a 100V cap on the plate easy easy easy, anything above 10V and I'm sorry but it seems rather a waste of a tube to be used as is and to disregard the other triode as well

Heck, you could be playing with high voltage!

I'm not that knowledgeable about tubes, yet.  So higher plate voltage gives more headroom and/or rounder overdrive and/or volume and/or....  Or does it depend on the overall circuit?

There is more to that question than can be said here, but the short answer is that GENERALLY when you have a higher plate voltage you get more clean headroom/more volume.  The overdrive characteristics depend on the circuit itself.  Yes high voltages are dangerous, but dang they sure make tubes a lot more fun.

[Renegadrian]

Still, you can use voltages like 50 to 100V, which are not lethal per se*, and have great results!!!

* I never got zaps from 50V, but hey a minimum of caution is a rule of thumb!

[sean k]

I did some tests a while back to see what my internal restance was... I set the resistance on the meter and held each probe in each hand. I measured about 2.5M and a friend of mine was over 20M! Average seems to be down under 500k. Add to that that I've been thinking that it matters alot whether we carry a balanced charge or a positive or negative charge and the question of how much we suffer from electrici
ty is that we all get different amounts. We have 250VAC rms in the wall which, incidentally adds up to well over 700V from positive peak to negative peak, and I get more than my fair share of them but they aren't much more than an annoyance. I don't like them, actually I hate them, but they've never been more than a "Bugger!"

All I'm saying, and I've never been zapped by DC at any voltage, is that we to are subject to ohms law but though it frightens me, high voltage, it doesn't deter me.

I made an artwork years ago that featured a jacobs ladder which I mistakenly put just above an aluminium plate. It also featured various infrared and subsonic detectors but as soon as the jacobs ladder started up it sent out so many radio waves everything else stopped working and the jacobs ladder had to be shut down by switching out the 12V power source. A slight benefit to the build was that the aluminium plate below the jacobs ladder used to charge up with quite high voltage from the emissions of the ladder and because I wasn't too happy with the people who were getting the artwork... I left it like that for them to find out... they did!