Author Topic: valvecaster power question  (Read 358 times)

BoredBassist

valvecaster power question
« on: March 06, 2018, 11:11:58 AM »
Hello, first post here, normally i just lurk on these boards to find answers to my questions but I currently am trying an experiment and couldnt find the answer by lurking so... here I am.

Anyways, i was building a valvecaster, the one that is just the tube socket and components. The ultimate goal would be to have it on my guitar. Im building a steampunk inspired telecaster and instead of just having a vacuum tube that does nothing why not have an onboard tube preamp? So i built that valvecaster and tested it out with a onespot, and it worked great! Tried it with an 18vdc power adapter and again, worked and sounded great. Now knowing i would probably need a rechargeable power source because valvecasters tend to eat up batteries, i bought a rechargeable 12vdc 6000mah lithium ion rechargeable pack with a max load capacity of 3A. I got it, plugged it in, and... nothing. No sound. The tube glows as normal, but im not getting any sound. I was wondering what the issue could be. Also, since most likely the rechargeable pack wont work, would any of you have any ideas on how to power it? I mean, push comes to shove ill just run the power through a stereo cable into a box on my pedalboard powered by a 12vdc wallwart.

Thanks!

vigilante397

Re: valvecaster power question
« Reply #1 on: March 06, 2018, 12:16:47 PM »
Welcome to the forum ;D

The first question I have to ask is did you double check polarity of the output from the power brick? OneSpots and similar pedal power supplies are center-negative, but pretty much everything else in the world is center-positive. Your heaters will light up either way as they don't really care, but you can't really feed a plate a negative voltage :P

If the brick is rated for 3A there's no reason I can think of that it shouldn't be able to supply the tube, it should be a perfectly viable power supply for a valvecaster.
"I'm not sure what "serious design flaws" you see. Does it explode or poison your dog?" - PRR

"Tayda's Whipping Boy" "Most Detestable Forum Member 2018"

http://www.sushiboxfx.com

BoredBassist

Re: valvecaster power question
« Reply #2 on: March 06, 2018, 12:33:00 PM »
Wait... what do you mean i cant break physics? Yeah i checked and the power supply is center positive. Its always the little things i overlook lol. Thanks!!

vigilante397

Re: valvecaster power question
« Reply #3 on: March 06, 2018, 05:54:10 PM »
I've been doing this almost 5 years and I literally made that same mistake last night :P

So does this mean it's working now? ;D I would love to see pics if you have them. I was thinking a couple years ago of doing a steampunk-ish guitar with an onboard valvecaster, but never got around to it. Such is life ::)
"I'm not sure what "serious design flaws" you see. Does it explode or poison your dog?" - PRR

"Tayda's Whipping Boy" "Most Detestable Forum Member 2018"

http://www.sushiboxfx.com

BoredBassist

Re: valvecaster power question
« Reply #4 on: March 10, 2018, 07:42:05 AM »
YUP! Got it working! It was a teensy bit more gain than I was thinking. Maybe switching it out with a 12bh7 would clean it up just enough. Currently the lowest gain setting still has a bit more hair to it than I would like. As for the guitar itself I don’t have any current pictures. But aesthetically speaking I was looking for something like a postal guitar https://reverb.com/item/9714897-postal-crossroads-barn-wood-handmade-guitar-hardtail-antique-natural-nitro-p90-neck-humbucker-bridge and a tony Cochran guitar https://www.tonycochranguitars.com/derringer.html. What I was thinking was make an acoustic style “soundhole” which is where the glowing tube would be.