Tube boost + overdrive running off a 9 volt battery

[Renegadrian]

12ax7??? Hey, how did you make it work??? How's the sound? And how much gain?
In the standard circuit the ax7 was too "boomy" and the sound was really bad...

[tranceracer]

aka_basse,
I'm curious too.  The EH AX7 I was using didn't sound to good.  the EH AU7 sounds much better.  Did you use the layout you posted?

[aka_basse]

12ax7??? Hey, how did you make it work??? How's the sound? And how much gain?
In the standard circuit the ax7 was too "boomy" and the sound was really bad...

Well, to me it sounds pretty ok. Its the standard curcuit with a few switchable mods, (including your favorite the tone-knob killer). Using it with the clean channel of my amp (valvestate 80v) works great, the channel otherwise sounds pretty boring. The valvecaster added some compression and with gain up I got a pretty good crunchy tone (the bass sounds kinda bad, but it always has on the clean channel). Used as a booster on the lead channel I actually think my stratoblaster made a better job (and together there is way too much wierd noise and distortion). So it wasnt bad. Perhaps not that amazing, but Ill have to compare it to another tube to get some perspective. Same goes for the gain, hard to say without comparing. The tube I use is a Marshall. The whole reason why Im not using a 12au7 is because im waiting for my order from banzai, and I wanted to see if the box worked.

One problem is hum when used with lead channel of amp. I have a voltage regulator in it, so is it just bad wiring or something?

[Darkness, Darkness]

On my side, thanks to this thread, I've played with 12AX7, more in a marshall plexi configuration than a valvecaster I must admit... and it works very great on my Emery Sound super baby heads: BIG sound  amazing ! But when trying it on the clean channel of my Marshall JCM900 it sounds awfull...a thin light dirty clean sound instead of the big roar... It looks like the gain from this setup (powered in 24V) is not so high in the end.

Is it the same for you guys who tried some 12AX7 in the valvecaster ? Or maybe it is linked to the plexi design  : I believe the distorsion is coming for a major part of the power section of this amp, not the preamp ? Well the "only" 24V" might be in cause too.... but regarding the so good results on the emery sound (which was my first goal) I 'll continue experimenting in this direction.

In my next parts order, I will try to add a phase inverter section with negative feedback ... and see what is happening.... For the moment I am trying to understand how phase inverters and output transformer works and what I could try   I wander if an isolation transformer right after a classic marshall phase inverter design (so without power amps tubes...)  could work in a stompbox design   Yeah, that's a pretty strange (maybe stupid) idea I have.... 

Anyway, once I'll have my final build, I'll share with you guys !

[Renegadrian]

Finished my take on the PEPPER SHREDDER using my layout here http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/PEPPER+SHREDDER.jpg.html
It works, altough I forgot to add C10 (220uF electrolytic) between 12v and ground. (I'll update the layout soon)
Put it in, and added a 7812 at the DC jack, I got a really good overdrive, but a countinuous hiss is coming as soon as I put the wall wart into the DC jack...
Any hiss hint??

[aka_basse]

Heres some pictures of mine, more in the pictures thread

[comfortably_numb]

aka_basse - where do you get those rails?  And also the small tube protector?  I like the look of the tube sticking out, but don't think I'd be comfortable without that kind of support.

Thanks,
Joey

Anyone gotten a chance to try out my mods?  I've got tubes coming, but I can't wait to know if it works!

[Pushtone]

Great looking pedal aka. A design after my own heart with roll bars and tube on top.
Those toggles are well protected too.



You can lower the height of the tube by using standoffs on the inside.

[aka_basse]

Pushtone: Yeah, got the rollbar inspiration from the pedal you posted earlier in this thread
Thanks for the standoff-idea, might do that if Im starting to stomp away the tubes!

Comfortably numb: The rail is a drawerhandle, and the tube protector came with the socket (along with a cover to put over the tube as well)

[Renegadrian]

Valvecaster V



Man, I love flames...

[kurtlives]

Looks great!

Where does one get those rollbars?

Also is there much of a difference? I have read the thread and there clearly is. I wanna know though if it is worth to build a dual "Caster". One with a 12AU7 one with a 12AT7...

[any]

Looks great!

Where does one get those rollbars?

Also is there much of a difference? I have read the thread and there clearly is. I wanna know though if it is worth to build a dual "Caster". One with a 12AU7 one with a 12AT7...

Those are just drawer handles, you can find them at most hardware stores..

[runmikeyrun]

i think home depot carries pink ones with hearts if you really want to be cool 

[tux320]

If I use Renegadrian's schematic for varo with no tone and I want to run it at 9v do I have to modify the circuit in any way?

[Renegadrian]

No man, just go straight following the layout...you can run it at 9 or 12v - altough we prefer 12v for the heaters, it will work good at 9v.
Let us know when you've done!!! 

[Renegadrian]

I discovered that there's also a 9AU7 tube - maybe it's less common, but I believe it could be used well for our projects?
After all, it shares all the 12AU7 details but the heater voltage...
http://www.nj7p.org/Tube4.php?tube=9AU7

[frequencycentral]

I discovered that there's also a 9AU7 tube - maybe it's less common, but I believe it could be used well for our projects?
After all, it shares all the 12AU7 details but the heater voltage...
http://www.nj7p.org/Tube4.php?tube=9AU7

How interesting. I do feel sometimes that everyones 12au7 Valvecasters running at 9 volts will one day all fail! A quick worldwide Ebay search shows a decent number of 9AU7s, cheap - but all in the USA.

[FlyingZ]

Awesome Matsumin pedal and my first non-looper build




The wires grew a bit 

[andrew_k]

Nice one!

How did you do such a clean job of those cutouts in the enclosure?

[FlyingZ]

Thanks, I drilled three 1/2" holes and filed the remainder. Two holes for the sides.