I was fascinated by gmoon's design for a super-simple guitar pedal, the ValveLiTzer, that used a tube as the heart of the effect. Unfortunately I don't play guitar myself, so I built one for my friend's birthday instead. Here are the results of my design. The circuitry is virtually the same, but the case is much different.

To build my version of the ValveLiTzer, you will need everything listed in gmoon's instructable. I bought nearly everything at Antique Electronics Supply, except for the LEDs (eBay), resistors and capacitors (local electronics shop), and wire.

EDIT: Be sure to check out an alternate version of this design, which I call the ValveLiTzer Trifecta. Same circuit, very different case!


1 12FQ8 tube
1 9 pin miniature socket
2 1/4" mono jacks
1 50k linear potentiometer
1 500k audio (logarithmic) potentiometer
1 SPDT (on/on) footswitch
2 blue LEDs
2 1000uF 25V electrolytic capacitors
2 1Mohm resistors
1 470k resistor
1 220k resistor
1 47k resistor
2 470 ohm resistors (for LEDs)
2 0.01 uF capacitors
1 0.1 uF capacitor
24 AWG stranded wire


about 2 square feet of 17mm thick Russian Birch Plywood (aka Baltic Birch)
about 1 square foot of 2-3mm thick plexiglass, Lexan, or polycarbonate plastic sheet
about 1 square foot of 3mm thick aluminum or brass plate
7 3/4" countersunk wood screws
some rubber stick-on feet
wood stain (your choice of colour, I used "Cabernet" red oil-based stain)
wood finish (I used Minwax Polycrylic water-based finish)


A band saw
A scroll saw
A drill press
A belt sander (or a sanding belt for the band saw) - optional, though good to have!
A Dremel tool with a drill press attachment
A 1/8" milling bit for the Dremel
A polishing bit for the Dremel
200 and 320 grit sandpaper
a 1/2" wide paint brush
A 1/2" wood chisel
assorted drill bits
and countersink bit - optional, you could also use a 3/8" drill bit
soldering iron


A variable output (up to 12V) DC power supply capable of 3 amps
a piece of scrap aluminum
a tub large enough to hold the cut aluminum pieces
salt water
a clothes iron
a laser printer
a sheet or two of glossy photo paper
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tewfik5 years ago
thank you for the instructable i'm trying to etch a smd stencil from aluminium and this is getting me crazy could this method be used to etch, say, about .5 mm holes ? the board is approx .1 mm thick, i ve tried the ferric chloride so far, but the etching is very not so precise
jeff-o (author)  tewfik5 years ago
Hmmm, it might work. I haven't tried etching holes straight through aluminum before, though. I think the biggest problem you'd run into is that the edges of the holes might be a little jagged, due to undercutting. Can you cut a smaller piece of aluminum and do a test to see what kind of precision you can get?
capth00k5 years ago
Great Instructable Jeff-o ; your write up is great as I was already planning on building a version of the ValveLitzer.

Just a couple of questions:

On the C1, C2, C3 - the capacitors ; are they 600v, or 400v?   Did you use the 4 pin 1/4 mono Marshall jacks found at Antique Electronics supply?  Where did you obtain the 16v 1000uf capacitors ; and are they absolutely necessary as I don't see them in the original schematic ; and I see you added another (2 instead of 1).

Again, awesome stuff and THANK YOU!!

jeff-o (author)  capth00k5 years ago
C1,2,3: It doesn't matter, since the circuit is running on 12V!

Yes, I think I used the Marshall jack. You can use whatever you want, though.

I got these caps at Sayal, a somewhat local electronics components chain. They shouldn't be hard to find, though. These filter the power supply and should be used if you're using a wall-wart ac/dc converter. If you're using a battery they aren't necessary.
capth00k jeff-o5 years ago
Thanks Jeff. Great work ; the LED lights and translucent bottom are a nice touch.
jeff-o (author)  capth00k5 years ago
 Thanks.  Most of the stuff I build lights up in some way...  ;)
gabrielG26 years ago
you can use Thinner to take the toner off, it's almost instantaneous
jeff-o (author)  gabrielG26 years ago
Cool, I'll try it next time I use this method.
Hey, here is my finished work, thought you may like to see it:




It has amber LEDS underneath the valve and the case, so it gives a lovely glow when on, can't get a good picture of it in the dark though:http://www.facebook.com/photo.php?pid=3685297&l=88ea6fafb6&id=630911404
jeff-o (author)  planet sutcliffe6 years ago
Very nice indeed! I like the "hammered" metal on top. Have you had a chance to use it much?
Yeah hammerite paint is wicked! I have used it a bit, not loads though, I'm bringing my studio back online after a forced absence (electrical problem) so I have lots of things to check and troubleshoot right now. It sounds WELL good though, the middle pot selects 1st/2nd stage of the valve, I replaced R3 and R4 with a 2 Mpot, and under advice from Gmoon connected a couple of resistors to make sure there would never be no load, and the wiper of this pot goes between the plates. It's very dynamic, there is a lot of control over the sound like this. You can read a more detailed expl. from Gmoon in the Valvelitzer (never rolls off the keyboard that word does it?!) comments
stevie16 years ago
if theres a hole in the middle of the socket for the tube it would be cool to put an led in ther and hook it up so the leds only glow when its turned on.
jeff-o (author)  stevie16 years ago
Hi stevie1, I'm almost finished building a second ValveLiTzer clone, and this time I installed an LED in that little hole in the socket. It looks great! Thanks for the suggestion!
stevie1 jeff-o6 years ago
no prob, i look for that stuff sometimes. i'm kindof obsessed with leds. i convinced my dad tto put leds on his mortorcycle and my moms bike too.
Wow, both your parents ride!! You're one lucky guy!! Dm
sortof... my dad dropped his first bike a couple years ago and now i cant get one till im 40! it sucks
Oh man, that stinks. He shouldn't project his failures onto you.
It's not a matter of dropping the bike...it's just a matter of when. Everyone drops their bike eventually.

jeff-o (author)  stevie16 years ago
Ha, nice!
jeff-o (author)  stevie16 years ago
Good idea! There is indeed a hole in the middle of the socket that's just the right size for a 3mm LED. Perhaps I'll try that the next time...
stevie1 jeff-o6 years ago
people probly think my dads a pimp cuz i convinced him to put purple on his!!!
jamilm96 years ago
thanks a CAD is something you can print onto a paper transfer it onto copper clad, etch it and make a pcb out of it.. I was thinking of using a clear case and this would look much more professional.
jeff-o (author)  jamilm96 years ago
Ah, you want PCB artwork. Sorry, I didn't design a PCB for this. I think you're on your own. I suggest downloading Eagle from www.cadsoft.de - it's free and easy to use.
jamilm9 jeff-o6 years ago
i have eagle, i just can't use it. Well thanks anyways.
jeff-o (author)  jamilm96 years ago
That's a problem then. I have the benefit of having learned it in college, but it's not that hard. Look up some online tutorials, there are some great free ones out there. It's a great skill to have!
jamilm9 jeff-o6 years ago
well i'm still in middle school but i will look at some tuts
jeff-o (author)  jamilm96 years ago
Sounds like a good rainy-day activity while school's out for the summer!
jamilm9 jeff-o6 years ago
i guess
jamilm96 years ago
has any one made a cad for this if so please post if not what is the cheapest tube amp kit(doesn't have to be guitar). thanks
jeff-o (author)  jamilm96 years ago
CAD? I've included the template I made in Illustrator, can you use that? As for the cheapest tube amp kit, do a search on Google. There are a few kits around, that include a board and all the parts you need.
itsachen6 years ago
Great instructable!
jeff-o (author)  itsachen6 years ago
Thanks! Glad you like it. :)
Pentagrid6 years ago
I know it's picky but can you remove the blue bar on the schematic? It covers part of the wiring making the circuit difficult to read:)
jeff-o (author)  Pentagrid6 years ago
Blue bar? I don't see anything on the schematic. Have you tried opening the schematic on the original ValveLiTzer Instructable? I copied it directly from there (with permission, of course!)
OK, this is weird. I tried again, didn't change a thing & the schematic is perfect!!!! Sorry if I've wasted anyone's time. John.
jeff-o (author)  Pentagrid6 years ago
No worries. Acrobat can be weird sometimes.
Phred17016 years ago
Ummm - I love the overall look and design, but isn't leaving the tube exposed somewhat risky, given the kind of environment where this will likey be used? In use, this is gonna get kicked. During setup and take down, not to mention storage and transport, well, that tube just ain't gonna survive... It looks great - don't get me wrong. Its just that it needs to be inside unless you want to be buying a new tube after every gig. Rock on!
jeff-o (author)  Phred17016 years ago
Not to worry! I built this for a friend of mine, who is very protective of his equipment and doesn't really take it outside ever. I've got a version 2 in the works that will feature a protected tube!
sleepygamer6 years ago
Awesome looking pedal, dude. I will add that I think the valve/tube should have a cage or something around it, as if it were used at a dark gig, a misplaced foot could easily shatter it. Most pro pedals that use tubes normally have simple metal bars above the tubes to prevent an accidental stomp, or they hide it in the bodywork. But other than that, I can't fault it! Great work! Looks gorgeous!
jeff-o (author)  sleepygamer6 years ago
Thanks! My next version will have the tube more protected. My friend isn't really the "play in the dark at a gig" type, so I figured the tube would be safe enough. But yeah, if the intent is to bring the pedal to gigs then it should be protected in some way.
Please can you give a more detailed explanation (perhaps a revision of the wiring diagram?) on how you wired in the caps to filter the power supply? Thanks! I'm going to make the original build but I may include this. Good job with the case build, it's very nice
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