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a tube box on 9V

Posted: 28 Jul 2014, 06:47
by kaya112
this is a tube box my first make
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Re: a tube box on 9V

Posted: 28 Jul 2014, 13:36
by kaya112

Re: a tube box on 9V

Posted: 28 Jul 2014, 13:38
by kaya112
PCB :P :P :P :P :P

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Re: a tube box on 9V

Posted: 28 Jul 2014, 20:19
by rocklander
what is it, and what does it do?
got schematic?

Re: a tube box on 9V

Posted: 28 Jul 2014, 20:44
by Dirk_Hendrik
Big boot waiting for encounter!!

Re: a tube box on 9V

Posted: 29 Jul 2014, 01:55
by kaya112
schematic

Image

Re: a tube box on 9V

Posted: 29 Jul 2014, 06:01
by DarkRain
Just a quick question: You are using 9v to supply tube heaters? It's a little bit under the specified voltage (12.6 between pin 4 and 5) - you could use 12v to supply the whole pedal and get more headroom and also you will be within the specs for the heaters.

Best regards,
Gabriel Tudoran

Re: a tube box on 9V

Posted: 29 Jul 2014, 08:27
by DrNomis
Looks like the schematic is based on the Valvecaster....... :hmmm:

Re: a tube box on 9V

Posted: 29 Jul 2014, 11:41
by Dirk_Hendrik
Below what we call a building drawing.
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The Schematic looks like this:
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Note the differences. The building diagram is handy for building the thing, even if you do not know what it does. The schematic is to understand what is going on.




(Thanks Simon, Valvecaster confirmed)

Re: a tube box on 9V

Posted: 29 Jul 2014, 13:33
by DarkRain
Ok ... but again... wouldn't be more convenient to use a 12V supply then a 9V? ?


Best regards,
Gabriel Tudoran

Re: a tube box on 9V

Posted: 29 Jul 2014, 16:43
by Dirk_Hendrik
Most definitely.

Re: a tube box on 9V

Posted: 29 Jul 2014, 16:46
by DrNomis
I agree Darkrain, 9V would mean that the cathodes of the valve aren't able to reach their full electron-emission capabilities, also, I seem to remember reading somewhere that if you run a valve at a lower heater voltage, it can lead to something called "Cathode Poisoning", incidentaly, I tried building a Valvecaster but it didn't work well and hummed alot..... :thumbsup

Re: a tube box on 9V

Posted: 30 Jul 2014, 13:10
by copachino
DrNomis wrote:I agree Darkrain, 9V would mean that the cathodes of the valve aren't able to reach their full electron-emission capabilities, also, I seem to remember reading somewhere that if you run a valve at a lower heater voltage, it can lead to something called "Cathode Poisoning", incidentaly, I tried building a Valvecaster but it didn't work well and hummed alot..... :thumbsup

what about 18VDC??

Re: a tube box on 9V

Posted: 30 Jul 2014, 14:09
by DarkRain
copachino wrote:
DrNomis wrote:I agree Darkrain, 9V would mean that the cathodes of the valve aren't able to reach their full electron-emission capabilities, also, I seem to remember reading somewhere that if you run a valve at a lower heater voltage, it can lead to something called "Cathode Poisoning", incidentaly, I tried building a Valvecaster but it didn't work well and hummed alot..... :thumbsup

what about 18VDC??
:) Well ... again why?! Standard voltage for heaters is: 6.3 or 12.6 so i choose 12.6 beacause:
1 i can supply the heaters with the same PSU
2 it's better the 6.3 in terms of voltage

Why to drop 3 volts or 5v on a resistor ... (@300 or 150mA it can get hot) when... you don't have to drop anything and use 12V as supply ...

Best regards,
Gabriel Tudoran

Re: a tube box on 9V

Posted: 30 Jul 2014, 14:32
by DrNomis
copachino wrote:
DrNomis wrote:I agree Darkrain, 9V would mean that the cathodes of the valve aren't able to reach their full electron-emission capabilities, also, I seem to remember reading somewhere that if you run a valve at a lower heater voltage, it can lead to something called "Cathode Poisoning", incidentaly, I tried building a Valvecaster but it didn't work well and hummed alot..... :thumbsup

what about 18VDC??


18V DC will burn-out the valve heater, unless you put a resistor in that'll drop about 6V (which means alot of power dissipation in the form of heat), once the heater burns-out the valve is useless...... :thumbsup

Re: a tube box on 9V

Posted: 30 Jul 2014, 20:40
by rocklander
DrNomis wrote:
copachino wrote:
DrNomis wrote:I agree Darkrain, 9V would mean that the cathodes of the valve aren't able to reach their full electron-emission capabilities, also, I seem to remember reading somewhere that if you run a valve at a lower heater voltage, it can lead to something called "Cathode Poisoning", incidentaly, I tried building a Valvecaster but it didn't work well and hummed alot..... :thumbsup

what about 18VDC??


18V DC will burn-out the valve heater, unless you put a resistor in that'll drop about 6V (which means alot of power dissipation in the form of heat), once the heater burns-out the valve is useless...... :thumbsup
how much current would it be drawing? would an lm7812 be the ticket?

Re: a tube box on 9V

Posted: 30 Jul 2014, 21:00
by DarkRain
rocklander wrote:
DrNomis wrote:
copachino wrote:
DrNomis wrote:I agree Darkrain, 9V would mean that the cathodes of the valve aren't able to reach their full electron-emission capabilities, also, I seem to remember reading somewhere that if you run a valve at a lower heater voltage, it can lead to something called "Cathode Poisoning", incidentaly, I tried building a Valvecaster but it didn't work well and hummed alot..... :thumbsup

what about 18VDC??


18V DC will burn-out the valve heater, unless you put a resistor in that'll drop about 6V (which means alot of power dissipation in the form of heat), once the heater burns-out the valve is useless...... :thumbsup
how much current would it be drawing? would an lm7812 be the ticket?
According to the DS it's 150mA per tube @ 12.6v that would be 18-12=6v dropout @ 150mA that would be 1W of power, a 7812 in a To220 package would be ok.

Best regards,
Gabriel Tudoran

Re: a tube box on 9V

Posted: 31 Jul 2014, 14:42
by kaya112
two tube box PCB
Image

Re: a tube box on 9V

Posted: 31 Jul 2014, 18:04
by Dirk_Hendrik
Looking forward to the 4 tube version!

Re: a tube box on 9V

Posted: 02 Aug 2014, 04:20
by atreidesheir
Dirk_Hendrik wrote:Looking forward to the 4 tube version!
It would be a beautiful pedal to look at.