Tube boost + overdrive running off a 9 volt battery

[Aren]

Just a thought - can anyone think of a 12V tube preamp (space charge tubes, maybe?) that will be clean enough to be used as a microphone preamp?

[Renegadrian]

I haven't changed the Valvy components to go cleaner...Others reported it can be a good clean booster with those changes...
Otherwise, maybe the huffer (see previous page) could do the job, but again I don't know personally...

[Renegadrian]

Got Valvy-addicted...I just can't stop playing thru this nice lil' box...
My fav tunes (the one this box fit well to my ears) are Whole lotta Rosie, Perfect Strangers, Demon's Eye, Black Dog, Hair of the Dog, Stargazer, Say what you will, Ready an' Willing, Gypsy Road...And the list could go on...

[forsakenrider]

I just ordered a 6111, and am thinking of powering a Subcaster from two 9v batteries in series - anyone know what difference this will make to the sound and any changes I may have to make to the circuit?

Dear frequency. I personally love 6111's and have build many headphone amps and hifi equipement with them. Youre double 9 vold is good in one sense... the tubes love more voltage... but you will need to regulat the heaters to 6.3 volts. the tubes do not like more or less. Then by adding a regulator you will lose a lot of your power through heat, thus eating batteries for dinner.

Try a 24volt wall wart with a regulator for the heaters and youre rockin'.

[forsakenrider]

Hey folks!  I don't see the point of running 12AX7's at low voltage when space charge tubes were designed for that purpose and sound freakin' great while they're at it.  Run a few of these in series and you can get anything from buffer to boost to overdrive.  See ya!

But where the heck can we find space charge tubes!! I tried looking, not too common on the 'Bay

[Fender56]

But where the heck can we find space charge tubes!! I tried looking, not too common on the 'Bay

http://www.tubesandmore.com/

[frequencycentral]

forsakenrider - i would love to see more schematics using the 6111 - particularly hifi - do you have any? Thanks

[Renegadrian]

But where the heck can we find space charge tubes!! I tried looking, not too common on the 'Bay

http://www.tubesandmore.com/

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=160227370765

Yes, maybe they aren't easy to find like the ol' 12A*7 family, but hey just browse a little...

[tranceracer]

I think the spirit of this li'l project is to use a tube that's relatively easy to find and works well in this application.  I was able to go down to my local guitar shop and pick up two 12AU7 on my way home from work.

I guess the next step is to move into more esoteric stuff to find that magic tone eh?   

[Renegadrian]

Yes, the TUBE ALCHEMY! 

[Chawk]

A couple of quick questions...

1) Should the 1uf capacitors negative leg be leading into the circuit or into the tone pot in the Beavis schematic?



2) Has anyone built and verified the original Matsumin valvecaster layouts? might be cool to have a PCB version of this too.





Thanks.

Matt

[forsakenrider]

[Renegadrian]

Matt, regarding your first question - I used a non polarized cap, it works great...
And, no I haven't tried the original Layout (not yet...)

Also I remember someone suggested the use of a SHO to fatten its sound some pages ago...I just built it one myself...
Well, my two Valvies seem to sound worse with something before/after them...Even if the SHO is quite good played alone, it just won't fit that well with the Valvy, even with the gain at its middle position...

[Chawk]

Thanks for the responses guys...

Bummed though because I tried it both ways and with a non-electro and it still isn't working... back to the lab I guess.

[TELEFUNKON]

Thanks for the responses guys...

Bummed though because I tried it both ways and with a non-electro and it still isn't working... back to the lab I guess.

Is your pinout of the tube correct?

[Chawk]

Is your pinout of the tube correct?

That is a good question... I actually ended up using an ECC802 but from what I've read they are identical to the 12AU7. I'm using a valve socket and it really only fits in one way. I'm stymied. works fine in bypass mode. when engaged I hear noise and when the strings are touched it sounds like a ground issue. everything seems to be wired up ok. probably just a matter of going over everything again.

[Caferacernoc]

Just a thought - can anyone think of a 12V tube preamp (space charge tubes, maybe?) that will be clean enough to be used as a microphone preamp?

If you build a Valve Caster and change R2 and R3 to 50k it would clean up nicely. That's with a 12au7 tube. The space charge 12u7 has a bit less drive and would be a little cleaner than that.

[puretube]

TopView/BottomView...

[Renegadrian]

Is your pinout of the tube correct?

That is a good question... I actually ended up using an ECC802 but from what I've read they are identical to the 12AU7. I'm using a valve socket and it really only fits in one way. I'm stymied. works fine in bypass mode. when engaged I hear noise and when the strings are touched it sounds like a ground issue. everything seems to be wired up ok. probably just a matter of going over everything again.

Matt, I believe that is a typo, you meant ECC82. you know us and europe have 2 different way to mark tubes, so an ECC82 IS a 12AU7.

If  you got a lil' piece of vero around, I'd suggest to go with that PERFECT layout (guess who drew it?!  ) that I personally used and is tested, verified and guaranteed...
http://img361.imageshack.us/my.php?image=valvecasterv05sv9.jpg
http://img245.imageshack.us/my.php?image=valvecasternotoneog3.jpg

Else I'd have to come there and take a look (and  my gf would be so happy, she lived there for some months and just love NYC, also our love story begins there, but I don't want to get you bored telling you all the story...)

[forsakenrider]

http://www.eurotubes.com/euro-e.htm
Some info on tubes from some SUPER awesome guys.
they only sell JJ tubes but matt is right, the EC802 is a 12au7 or ECC82 variant. But it should definitely work.

Any pics matt? maybe one of use with a working valvey can spot the issue? also, what are you using for power?