Tube boost + overdrive running off a 9 volt battery

[guitarman89]

Another experiment report for the records...
I tried to put in a 6021 (submini dual triode tube) powering the heaters thru a 7806 (it must receive 6.3 V)
The pins follow the 6111 schematic you can find in the first pages

It works but the sound it's not good at all...Guess I have to breadboard it and find the mandatory tweakings that could make this tube shine!!! Not for now, though...

  Here you go Adriano. The first schem is straight high gain. The second is med/high gain with over the top gain switching. Also added an EQ by-pass switch to allow the full tone without any loss.
  Sounds good at 18 volts but increase the voltage and it becomes more amp like, especially above 24 volts. With some minor tweaks it works at 12 volts, but at 12 volts it is hard to get the palm muting chunk you want with high gain.

is it possible to use the second schematic like a little preamp at low voltage (18/24 V)??

[Smiler]

FINALLY put everything together!! 

After a while my Twincaster is finished. Got some pictures for you:







More Pictures: http://s386.photobucket.com/albums/oo302/Smiler/

Enjoy and thanks for your help finding errors!

[Renegadrian]

It looks so nice! Congrats on this one!!!

[mth5044]

That's really Smiler.

Although you might want to watch out when changing the knob settings.. if the tubes get hot.

Ouch. 

[puretube]

Tube-Builders do it "Sticking Out"!

[Renegadrian]

my green machines...

[Renegadrian]

Triode Triode

I made a layout last month and built it, but it didn't work at first, I debugged it yesterday, and well, it was just a track break I forgot - now it works so good and it surely has a good amount of gain!!!
I read some posts about it at page 9, but it's not clear if the design is by brett, and the schem doesn't report its creator...

So brett, if it's your work, let me know and I'll add proper credits in my layout,ok?

[frequencycentral]

Triode Triode

I made a layout last month and built it, but it didn't work at first, I debugged it yesterday, and well, it was just a track break I forgot - now it works so good and it surely has a good amount of gain!!!
I read some posts about it at page 9, but it's not clear if the design is by brett, and the schem doesn't report its creator...

So brett, if it's your work, let me know and I'll add proper credits in my layout,ok?

I don't see a schematic for that on page 9 - looks like its disappeared! Can you post one? How does it compare with the stock Valvy?

I really liked your Vibracaster soundclips by the way Adriano.

[Renegadrian]

this is the schematic I used - just changed the uper parts, but that's just the power section - actually it hasn't got a 7812 but I think I'll put one in - for now it's just a vero with "flying wires"

It's not that far away from the Valvy...maybe a little more gain...I'd suggest you to try it, after all it's just a simple circuit...

Still working on the V2, but the trimpot you suggested me didn't work...

I am glad you liked my Vibracaster and its samples - thx for such a good circuit!

I am raising my glass of Nero d'Avola wine at that tube s..t!!! yeah!!!

[frequencycentral]

Looks identical to the Valvy but with larger value caps, and gain set to maximum. Probably more bottom end, and the 500k volume pot will make the maximum volue louder (maybe?) Too similar for me to build really.

I've just cleared my breadboard of my last project (Multimode Filter), so I'm gonna have a play with "V2" again over the holiday.

[runmikeyrun]

Well after reading all 45 pages i have spent several hours soldering up a twincaster on vero (thanks Renegadrian!).  I'll have to pick up some tube sockets on Saturday am and then fiddle with r2/r3 values but it's otherwise pretty ready to be fired up.  I dug out my rca 12au7 and philips JAN 12at7 so i can see what this thing can do.  I'll be going for a high gain application on bass guitar.  Hope this sounds good on bass!!!

[Renegadrian]

Right, post the final results then!!! 

[703224796]

I have a question about the pedal sale situation:  I am planning on building one of these, and selling it on Ebay for a few extra bucks (college loans suck, don't they?! ).  Is there any legal implications that I must know before doing this?  I feel like matsumin is going to sue me or something ...lol....I just want to make sure I don't do anything stupid.  Thanks

[Renegadrian]

Build it for yourself - don't sell it.

[squallc]

Hi there, I have built this Original Mitsumin Valvecaster, actually, i have some loud HUM sound, is it probably because of power supply? how to clean the power supply?
Need your suggest to clean this HUM.
Thanks 

[frequencycentral]

Hi there, I have built this Original Mitsumin Valvecaster, actually, i have some loud HUM sound, is it probably because of power supply? how to clean the power supply?
Need your suggest to clean this HUM.
Thanks 

You see that 'Triode Triode' schematic a few posts above your post? Build the voltage regulator part of that circuit and apply it to the plates of your Valvecaster. 

[Renegadrian]

Rick, it should be quieter than the 100µF alone on the dc jack, am I right?!

[frequencycentral]

Rick, it should be quieter than the 100µF alone on the dc jack, am I right?!

Quiet and more stable - unregulated '12 volt' supplies can vary wildly upwards from 12 volts. You wouldn't want 17 volts across the heater right? That's a neat little circuit. However, I just use a single cap - but my power supply is very stable.

[Renegadrian]

Yeah, I meant the 7812 and the cap on the dc jack...As I always do...

[Albot]

Aw man! I'm getting frustrated here!
I tried this circuit out (original valve caster) with a non center tapped ecc85 before and ran it at 6.3 volts and it worked out fine.
Had some problems with it lighting up like a lightbulb when running on 9/12 volts (go figgure)-

Now however i've got some brand new ecc82's and they light up like lightbulbs when i try to run the heaters on 9/12 volts in SERIES.. I do use pin 4 and 5 for power and I meassure about 8 ohms across pin 4 and 5 to pin 9 and about 16 ohms across pins 4 and 5 so it makes sense.. except it doesent work (works way to well rather).
I use a regulated powersupply that i've checked a dozen of times.

I guess the only thing that could do this would be if pin 9 was grounded but it's not.. I've checked and checked again.. acctualy concidering drilling the socket for pin 9 out.