Tube boost + overdrive running off a 9 volt battery

[Dongle]

Alright... You can also rectify the ac-current with tube-diodes. But make sure, the whole chain from the powerplant to your pedal uses tubes (Sorry, just joking - I know the difference)

Did you try the tube buffer? Sounds interesting...

Actually, I always really wanted to build a tube screamer (TS808) with a tube based Op-amp... But its still to complicated for me.

Still, I think the buffer behind my valvecaster enhanced the sound, although there is an "evil" IC in the circuit.

[Renegadrian]

you could use another AU7, one triode for buffer and one triode for MORE boost. switchable or fixed.

[Yeahno]

Forgive my newby-ness...

So tube buffer before tube would be the Twincaster?  And the IC before tube would be Adrian's Valvy circuit?

Spent a bunch of time on Youtube trying to find Twincaster clips.  Lots of Valvecaster stuff, mind you.

[iccaros]

Well I have been reading the tube pedal book here ... and I got the basic (   revision: 1.0 from 30 October 2008 from a beavis audio research breadboard layout)  Valvecaster working on a breadboard. The more I play it the more I like it.  But I  see from this material that there are "improved" Valvecasters and a valvemaster and other versions of this tube pedal.

So the question is:    Which of these versions will sound best when run on 12 volts?        Can one power a revision 1.0 Valvecaster with a regulated power supply made with a IC 7812  and improve its sound?

What effect would using a B50k pot for the tone pot have on the sound of the pedal? 

Thanks.

this is a hard question to answer, you see this is a starved plate design, and way out of the Linear operation of the tubes we are using. IF you had a 12u7 (hard to find) which is a 12v tube than this would be easier to answer as we could draw a good load line, but we can not tell you if it sounds better, that is up to you.  The only way to know is try, I find it interesting that even the same tube type (12au7 for example) from the same manufacture can sound different

[Teo87]

Hi guys! i'm new of the forum and i'm italian so prepare yourself to a lot of errors from me 

I built the basic valvecaster, VOL  GAIN  TONE with an ECC82 JJ and the standard components on page 1...
It works fine in bypass...  no rumors ecc ecc and the signal pass all!!
It runs on 9V, the tube lights on, also does led but, when i run the pedal, it low a lot volume even at maximum of VOL and GAIN...

i checked lot of times che circuit and it fits the shematic.. 
What could i do??



thanks!!!

[Renegadrian]

@Yeahno
Twincaster as the name implies is just a valvy x2 (in series)
It could be a starting point for experiments to add to the classic valvy schem another double triode, one for another boost stage and one for buffer (in or out) - that is not related to my valvy layout (which is almost standard, just the tone removed) and based on original dano's schem.
basically using a cathode follower you have gain=1 and buffer.
mandatory reading = http://www.freewebs.com/valvewizard/accf.html

Teo, please give more information or...scrivimi in pvt se serve ok?!

[Yeahno]

Twincaster as the name implies is just a valvy x2 (in series)
It could be a starting point for experiments to add to the classic valvy schem another double triode, one for another boost stage and one for buffer (in or out) - that is not related to my valvy layout (which is almost standard, just the tone removed) and based on original dano's schem.
basically using a cathode follower you have gain=1 and buffer.
mandatory reading = http://www.freewebs.com/valvewizard/accf.html

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

Adrian: Thanks for the tips and the link.  I'm going to wade through the tube stuff.  Perhaps some of it will rub off.

Cheers,

[Teo87]

I used this scheme  http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=39952&g2_serialNumber=2   to make the valvecaster standard...

I did the circuit well, checked 3 times...

Bypass mode it's ok, no volume decrease, no rumors...
Attive mode, even with VOL knob at maximum, i have maximum half volume then bypass mode...    GAIN and TONE knobs works correctly, i can hear them... but volume goes to 0% to 50% of the bypass mode...

Can you find something wrong in the  wiring diagram?  wrong components??

I have used carbon resistence, 100k/470k/220k/1M/400 ohm (for blue led)
I have used polyestere capacitors 47n/47nf/10nf/ and 1 electrolitic polarized 1mf
3 POTS  100k 100k 50k
3PDT footsw
And i run it on a brick 9V 1Ampere

[iccaros]

can you post tube voltage.
also what I find helpful, if you can insert a signal (play the guitar) and give us the AC voltages, while playing,  on pin 2, pin 1, pin 6 and pin 7
thanks

[Teo87]

Here is the datasheet   http://drtube.com/datasheets/ecc82-jj2003.pdf

AC voltages with tester are:

PIN1   12V
PIN2    0V
PIN6   14,8V
PIN7    0V

[iccaros]

those are DC right? if those are AC, we have big issues.
what is your power source?

[Teo87]

nope... reported AC as you asked me..    set tester on 200V AC to take measurements.

i use a BESPECO PS-50  1 Ampere     5 exit on 9V

[Teo87]

PPS:

I tested also DC and i got:

PIN1    6.86V
PIN2   -0.01V
PIN6    7.74V
PIN7   -0.12V

[iccaros]

what is the DC voltage read directly from the power supply, what is your DC on each pin? are you using a voltage booster? 200vac range is too large, do you have a 10 or 20v range?
you should see about 100 - 300mv ac from the guitar coming to pin 2, this should give a swing of about 1vac to the next stage (from pin 1 over the cap to pin 7)
Pin 6 output should not swing higher than 1.5 - 3 volts I would think.

in comparing your DC to AC, something is wrong with the AC readings, as there is no way you can have  a larger AC swing than DC in this design, unless your power supply is putting out AC..

[Teo87]

PowerSupply send 9V stabilized DC.  i can read about 18V AC on the same jack of tha daisy chain...  I tested with the tester in DC and it send about 9.14V

I'm not using any voltage booster, just plugging the power to the http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=39952&g2_serialNumber=2  scheme!

My tester only has  750/200 V  AC scale and  200m  2000m   20v   200v  1000V  DC scale

[iccaros]

PowerSupply send 9V stabilized DC.  i can read about 18V AC on the same jack of tha daisy chain...  I tested with the tester in DC and it send about 9.14V

I'm not using any voltage booster, just plugging the power to the http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=39952&g2_serialNumber=2  scheme!

My tester only has  750/200 V  AC scale and  200m  2000m   20v   200v  1000V  DC scale

there is your issue, that power supply is putting out way too much ac, its crushing the little signals from your guitar and from the tube. I would suggest using another power supply, use a different position on the supply, and testing, use a 9v battery if you can, this will tell you if the rest is correct.
The DC voltages look good, or at least OK..  you do have 9v between pin 4 and 5?

[Rick899]

I found an 11 page document online titled "12AU7 Valvecaster".   On page 4 of that article is a schematice of a "Dual Valve Caster"   and below that is a vero board layout by Renegadrian of the Twincaster.

Is the Dual Valvecaster the same pedal as the Twincaster?   I am a novice at all this and am confused by the Dual  Valvecaster schematic which has two  R1, two R2, etc.   Should the tubes be V1A+V1B and V2A+V2B?  If I were to build the Dual Valvecaster from the schematic, how do you deal with two of each component?   For example if there are two R1 resistors should they be treated as R1a and R1b in order to precisely distinguish between the two and the specific location in the circuit where they go?

The dual has 14 caps and resistors and the Twin has two of most of the components (labeled for example 2a and 2b) for a total of 11, so they seem to be different.  

Is there a schematic of the Twincaster available to forum members ?   I haven't been able to find one. But I have seen the layout numerous times.

I am still debating over which pedal to build .... the Valvecaster (which as I have said I already have working on the breadboard), the Valvemaster, the Dual Valvecaster, or the Twincaster. Which pedal will work best on 12 volts? Which will be the quietest and have the greatest range in terms of boost and of clean to distortion?  I have all the parts I need including some NOS RCA and Sylvania 12 ax7 and 12 au7  tubes and am itching to get started.  PLease answer my questions and help me decide. Thanks.

[Teo87]

8.90V between pin 4 and pin 5
I'll try with a 9V battery then i'll repost you...

[Teo87]

PowerSupply send 9V stabilized DC.  i can read about 18V AC on the same jack of tha daisy chain...  I tested with the tester in DC and it send about 9.14V

I'm not using any voltage booster, just plugging the power to the http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=39952&g2_serialNumber=2  scheme!

My tester only has  750/200 V  AC scale and  200m  2000m   20v   200v  1000V  DC scale

there is your issue, that power supply is putting out way too much ac, its crushing the little signals from your guitar and from the tube. I would suggest using another power supply, use a different position on the supply, and testing, use a 9v battery if you can, this will tell you if the rest is correct.
The DC voltages look good, or at least OK..  you do have 9v between pin 4 and 5?

yep   9V between pin 4 and pin 5...  8.94 exactly!

Tomorrow i'll try with a 9V battery

[frequencycentral]

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.