Tube boost + overdrive running off a 9 volt battery

[Yeahno]

I'd be interested in your opinion re any differences/advantages of either varient.

I'm afraid I can only speak to the perceived differences. I'm going to leave the engineering aspects of it to the people here who are qualified to make such judgements.

I think the circuits sounds "rounder", if you can imagine such a thing.  I can't discount the manner in which I breadboarded the thing - it all matters, I suspect.  The tube seems to run perceptibly hotter; that is, the actual tube seems hotter to the touch that the Valvecaster.  Is that "good"?  I have no idea.  I prefer what the Gain pot does sitting between the tube segments.

I've lucked out into a wall wart that's providing a solid 12VDC/1A and it's actually quiet.  Very curious to see what stacking a couple of ValveMasters together might sounds like (TwinMaster?), and my reading suggests that 1A might be enough to power it, but again, I'm obviously not an engineer and cannot empirically say.

I want about 50% more crunch than I have, without it getting all crazy.  Read some of the notes suggesting messing around with R2 & R3 and I may do that, but I need to understand more about the implications of this before doing so.

It sounds good to me. 

[iccaros]

Heh.  The Valvecaster on the breadboard has just become a Valvemaster.  The sound is growing on me.

I'd be interested in your opinion re any differences/advantages of either varient.

Rick I have been playing with the valvemaster, but at 46v (I only had 50v caps..)
so far I can get good tone from this but the 10uf on the cathodes allows too much bass, only one tube I have does not "Fart" out once the gain is raised.
I will go to a 1uf and then play from there. will let you know

I also changed the plate resistors to 68K  and I have no tone stack but I am thinking of using the Garnet stack

[Renegadrian]

136 pages and memory starts to fall...don't remember if that was argumented enough, but hey sometimes it's good to go back to basics, it can be helpful for new guys and for veterans as well...
Trying to help out my country mate Teo, I remembered/realized that small difference between original Dano schem and original Dano wiring example.

As you can see, there's a small difference in the way the tone parts (pot and c4 cap) are arranged.
In the schem, after c3 (1µ polar. or NP) there is one leg of c4 with the other leg to the tone pot (pin 1) and then to ground (pin 3 and 2). also after c3 there's tied the volume pot.

in Dano's wiring the the tone pot is just after c3, at pin 3 (and it works the opposite that way, fulyy CCW you have no attenuation of the highs) and the signal to the volume at the same outer pin of that tone pot. c4 comes from the wiper of tone pot and then to ground. I don't know if that makes that HUGE difference (I believe not) but maybe it's something to point out. My very first vero layout was made using the wiring diagram as its starting point.

[iccaros]

Heh.  The Valvecaster on the breadboard has just become a Valvemaster.  The sound is growing on me.

I'd be interested in your opinion re any differences/advantages of either varient.

Rick I have been playing with the valvemaster, but at 46v (I only had 50v caps..)
so far I can get good tone from this but the 10uf on the cathodes allows too much bass, only one tube I have does not "Fart" out once the gain is raised.
I will go to a 1uf and then play from there. will let you know

I also changed the plate resistors to 68K

try a 12at7, I found that in the same CKT as a 12au7, low voltage, it give more crunch.. I picked 5 up on ebay for $20..

[Renegadrian]

Also I'd like to give a little suggestion at the new guys, like Yeahno and Rick899...

There are two paths for you, based on your needs or will to experiment...

- path a - K.I.S.S.
Valvecaster is such an easy ckt to build, it give a nice and warm booster/overdrive when used at 12V with the right tube.
Get rid of the useless tone pot as I did shortly after my first one like 3 years ago!

- path b - more complete builds
A valvy is not that much different from the first two tube stages of your ordinary tube amp - studying tube preamps may lead you to my same conclusion. Some already went further, like the great ROG renditions of tube preams/amps with FETs, or cloning a preamp, like the jcm800 preamp you can find on the net. it is the whole preamp part, 4 gain stages (using 2 tubes) with regular TMB tone stack.

As long you got your feet wet with tubes, you cannot go back...just choose your path!

[Dongle]

Adrain,
Thanks for the link with the tube buffer!!
Interesting... Did anyone try this with low voltage (12-50V)?

[Teo87]

I still have no tryed with a 9V battery...  i fixed some GND to the circuit but it does the same error...

I took again values on PIN1/2/6/7 and i got the same values...

But...   i set scale on 200mv and i took signal directly from 6.3jack from the guitar (a stratocaster 70 with vintage custom shop PU ).

I had signals around 0-30mv maximum...
I tryed to pick up signal from PIN2 with a compressor before the valvecaster and i have only 20mv while i read arount that it should be at least 200mv...
Should i try to change R1 1Mohm with a one with less resistance?

[iccaros]

R1 is a grid leak resistor and should not be in path of signal.  Reducing that would not help.

this may help
http://www.diystompboxes.com/pedals/debug.html

[Teo87]

fixed it...
I found a 24V  1Ampere power supply stabilized at home...   it runs very very very well!!!

Thanks a lot guys!!!!

[Teo87]

PS: fixed work tension to 12V (12.4 from the tester)
It runs very fine!

I also added a little red led that were alone in one of my work boxes under the socket!

This is the result!

[iccaros]

nice job, so it was just the power supply?

[Teo87]

thanks!
yep, it was just the power supply!

i supposed it would had more gain..   i play classic blues like clapton/dire straits wiyh my group..    i usually play rithm OD with the crunch canal of my peavey classic 50 end i boost signal with the pedal OD (in this case the new one).
So, is there a way to gain a little more overdrive changing some components?

[JRM]

I'd be interested in your opinion re any differences/advantages of either varient.

I'm afraid I can only speak to the perceived differences. I'm going to leave the engineering aspects of it to the people here who are qualified to make such judgements.

I think the circuits sounds "rounder", if you can imagine such a thing.  I can't discount the manner in which I breadboarded the thing - it all matters, I suspect.  The tube seems to run perceptibly hotter; that is, the actual tube seems hotter to the touch that the Valvecaster.  Is that "good"?  I have no idea.  I prefer what the Gain pot does sitting between the tube segments.

I've lucked out into a wall wart that's providing a solid 12VDC/1A and it's actually quiet.  Very curious to see what stacking a couple of ValveMasters together might sounds like (TwinMaster?), and my reading suggests that 1A might be enough to power it, but again, I'm obviously not an engineer and cannot empirically say.

I want about 50% more crunch than I have, without it getting all crazy.  Read some of the notes suggesting messing around with R2 & R3 and I may do that, but I need to understand more about the implications of this before doing so.

It sounds good to me. 

There's no recorded example of the differences? That would be great as all you can hear on you tube is valvecasters both on 9V and 12V. They're OK but if the valvemaster is even better that's the circuit I should go for.

[Yeahno]

There's no recorded example of the differences? That would be great as all you can hear on you tube is valvecasters both on 9V and 12V. They're OK but if the valvemaster is even better that's the circuit I should go for.

I'm an even worse guitar player than I am a circuit bender. Otherwise, I'd oblige.

I didn't say it was better.  I said I liked the way it sounded.  I prefer it. 

That said, converting from the Caster to the Master took me all of about 15 minutes, once I'd soldered up a different pot, so build both.  It's good fun!

[iccaros]

thanks!
yep, it was just the power supply!

i supposed it would had more gain..   i play classic blues like clapton/dire straits wiyh my group..    i usually play rithm OD with the crunch canal of my peavey classic 50 end i boost signal with the pedal OD (in this case the new one).
So, is there a way to gain a little more overdrive changing some components?

try a different 12au7 or in my case the 12at7 gave more gain.

[JRM]

There's no recorded example of the differences? That would be great as all you can hear on you tube is valvecasters both on 9V and 12V. They're OK but if the valvemaster is even better that's the circuit I should go for.

I'm an even worse guitar player than I am a circuit bender. Otherwise, I'd oblige.

I didn't say it was better.  I said I liked the way it sounded.  I prefer it. 

That said, converting from the Caster to the Master took me all of about 15 minutes, once I'd soldered up a different pot, so build both.  It's good fun!

I might do it! But first I have to finish my vintage multi-fx. I have it halted for over one month and I realy want to finish it first before I jump into another project. But I'm pretty shure that the spare old Philips tube will end up on one of this babies.
I've read the article about triodes operating at low voltages and it's very interesting and easy to understand even for a non-electronic engineer like myself (although it requires that you know some basics).

[Renegadrian]

 the Valvemaster:



- interstage gain pot - no more crackle - like a 'real' tube circuit.  
- proper cathode biasing of both triodes - like a 'real' tube circuit


Here's my freshly made Vero layout may you ever need...

[fretzburner]

Is this applicable with 12AX7?
thanks

[DavenPaget]

No doubt ,yes . They are the same except you get MOAR gain with 12AX7 .
PS : Your tube's base are belong to me 

[iccaros]

Is this applicable with 12AX7?
thanks

While a 12ax7 has more gain, I have not found it to be so in this low voltage design. I get almost unity gain at 12volts and at 45v it works much better but the 12at7 and 12au7 give me much more gain, and more grit.