Valvecaster at 12 Volts?

[GibsonGM]

Give it a shot. I forget if the regulator 'drops out' if there is too little voltage and just allows the lower voltage thru or blocks the voltage completely.
I believe it just won't regulate, and you'll have the lower voltage....won't hurt anything.

[sundgist]

The regulator should put out around 10.5v with 12v input.
Won't harm anything though I'm not sure how the lower voltage will affect the heaters function. I've read different opinions about straying too far from 12.6v.

[anchovie]

The original Valvecaster schematic runs the heaters at 9v, so 10.5v should still work.

[jaki54321]

Give it a shot. I forget if the regulator 'drops out' if there is too little voltage and just allows the lower voltage thru or blocks the voltage completely.
I believe it just won't regulate, and you'll have the lower voltage....won't hurt anything.

Hmm ok. Ill see wat i can do =)

[jaki54321]

Give it a shot. I forget if the regulator 'drops out' if there is too little voltage and just allows the lower voltage thru or blocks the voltage completely.
I believe it just won't regulate, and you'll have the lower voltage....won't hurt anything.

Ok i got all the parts soldered in. I bought a 1000uF Electrolytic capacitor, which was a lil bigger then i expected... But i was able to fit it in the pedal, I also got a 7812 voltage regulator and put them both in as i saw on a diagram. I plugged it in and WOW! All the noise was completely gone! No buzzing or hissing, jus pure guitar true tube overdrive! However, it was not as powerful as it was before. I plugged in my 12 volt jack with the new parts, and the tube did not glow as bright as it used too. I believe i just have a lower voltage because im putting in 12 volts into a 12 volt regulator. It works however, very well. When I buy my dunlop DC power brick, and i connect the 18v plug, will it regulate down to exactly 12 volts and will the tube be jus as powerful as the 12 volt without the regulator(but without the noise)?

[pleiades]

The 7812 will regulate your 18V supply down to a smooth 12V, but whether or not the pedal is as loud as it was with your unfiltered 12V supply is up in the air.  Your old supply was advertised as delivering 12V for its rated load, but since it was rated 500 mA and your valvecaster was drawing less than that (at least, it should have for a single 12AU7 operating in spec) the unregulated supply was very likely putting out a voltage greater than 12V, so your final result with the 7812 and the 18V brick will not be quite as loud as when you used the 12V unregulated supply.  It will be louder than the 12V brick with the 7812.

[jaki54321]

The 7812 will regulate your 18V supply down to a smooth 12V, but whether or not the pedal is as loud as it was with your unfiltered 12V supply is up in the air.  Your old supply was advertised as delivering 12V for its rated load, but since it was rated 500 mA and your valvecaster was drawing less than that (at least, it should have for a single 12AU7 operating in spec) the unregulated supply was very likely putting out a voltage greater than 12V, so your final result with the 7812 and the 18V brick will not be quite as loud as when you used the 12V unregulated supply.  It will be louder than the 12V brick with the 7812.

hmm ok man Thank you! I think I got this all planned out now. All the electronics are in(finally...) with the filter 1000uF electrolytic and the 7812 supply. No noise, no issues. Jus need 18v lol.

[GibsonGM]

Yes, you might need to tinker a little, and try more than one power supply.  Sometimes, "forcing" a circuit with a little higher voltage can make a real difference!  As long as you don't exceed the ratings of parts like capacitors etc.

You can step up the voltage coming from a 78XX regulator by adding diodes to ground from the 'common leg'.  They will step it up in .7V increments.  I use 1N4001 or better diodes, cathode going to ground to do this.  If you use 3 diodes, it would boost you to about 14V.

If you had an LM317 adjustable regulator, you could use an 18V wall wart and get something like 15V out of it....to get 18V out, you'll need the LM317 and an input voltage of at least 22VDC (best achieved with a transformer and rectifier, IMO).

I keep LM317, LM7812, LM7809, LM7805 around for projects like this! 

[GibsonGM]

PS - watch that heater voltage.  If you go higher, you can use a voltage divider or zener diode to keep it within the realm of where it wants to be.  12V is ideal...

[jaki54321]

PS - watch that heater voltage.  If you go higher, you can use a voltage divider or zener diode to keep it within the realm of where it wants to be.  12V is ideal...

I would try your suggestions man but i am officially out of room inside of the pedal xD i bought the enclosure thinking it would be bigger, uh nope xD I got a small bear 'BB' Enclosure, not very big  Well if i jus got a Dunlop power brick and ran 18 volts to the pedal, the regulator will drop it down to exactly 12 volts right? I jus want it 12 volts.

[GibsonGM]

Yup!  That will leave you some other projects to do another day   

[jaki54321]

Yup!  That will leave you some other projects to do another day   

Ok man thank you for all your help and patience with me  idk wat i would have done without ur help

[GibsonGM]

Not a problem, J...that is why we're on here!  Gives us something to do, and keeps us on our toes, ha ha.