Breadboarding a DIY Tube Overdrive Guitar Pedal and Other Things!

In this video I'm showing off some of my PCBs for helping with guitar pedal prototyping and show how you can build a simple tube overdrive on a breadboard!
Also I'm filming with a new camera, so everything is a little weird. Sorry.
The schematic shown in the video has a mistake, you can find the more extensive and corrected version here: github.com/NuclearLighthouseStudios/Triode-Sun-Breadboard-Edition/releases/download/r02/Triode.Sun.Breadboard.pdf
All the files for the Baguette tube adapter are here: github.com/NuclearLighthouseStudios/Baguette
And the Switchboard files are here: github.com/NuclearLighthouseStudios/Switchboard

[@RijuChatterjee]

That sounds ridiculously good! Was it really just the raw recording from guitar->circuit->soundcard? Any processing or amp simulation?

[@KrisSlyka]

Thanks! And yeah, that's just the direct signal from the circuit into my interface. No further processing added in post.

[@RijuChatterjee]

@@KrisSlyka wow, I really want to build something like this now. Do you think a low voltage circuit like this would work with those Chinese 6J1 tubes? They're so cheap...

[@KrisSlyka]

@@RijuChatterjee Hah, funny you should say that. I actually built a tiny class A amplifier with one of those a while ago. imgur.com/EDyslC3 It's running at 24V and puts out enough power to drive a 1x12 speaker at acceptable volume. It's just a 6J1, some passives and an old 12V wall wart transformer as output transformer.

[@RijuChatterjee]

@@KrisSlyka Damn, okay that decides it - I'm ordering some 6J1s right away. Thanks!

[@jbolt247]

Hey Kris, great video. I found this after searching for a diy 12au7 preamp. The issues I have with the existing micro class ab amps like the orange micro dark or micro terror is the high mid, unpleasant sizzle, and little to no eq adjustments. I ended up adding an eq and reverb pedal to my micro dark and ran it into a 112 cabinet and was blown away by the sounds I was able to get. Unfortunately the best thing about the micro dark was now gone. The portability and easy setup. So I ended up disassembling the pedals and amp and built my own box to put all of the separate components in. It works great. Now I would like to try to build one from scratch but I am software developer and my circuit knowledge is very limited. Have you ever considered adding a solid state amp section to this and possibly an eq section or reverb? Also, can you add a link to the tube breadboard adapter and schematics? Thanks Jamie

[@KrisSlyka]

Hey, thanks! Yeah, I've thought about expanding it and have a few ideas on how I would turn this into a kind of hybrid amp. Probably add a second preamp tube that can be switched in and out for a high (distorted) and low (cleanish) gain setting, a simple EQ/tone control, and maybe a spring reverb driver all coupled to a class D output stage. None of this should be too complicated from a circuit standpoint and building it this way should allow you to tailor the sound into something way less harsh. Links for everything are in the description, the schematics can be downloaded from the releases page: github.com/NuclearLighthouseStudios/Baguette/releases/

[@jbolt247]

@@KrisSlyka Thanks for the quick reply. I am working from my laptop now and I see that you had already included the links above. Sorry. For some reason they were not showing on my iPad last night. The updated schematic is a big help. I will be purchasing a bread board soon and I will see if I can get this working for myself. I would love to see you take this to the next step as you mentioned above. Subscribed, so I will be looking for notifications.

[@jtmotenz]

Hey man, I’m literally planning on doing the exact same thing. Were you able to power the pedals by the amps power itself? Meaning you don’t have two power supplies to plug in the wall.

[@janoshtrenhem3573]

Hey Kris, awesome stuff !! In your schematic for the pedal there is Power Filtering shown, is the power filtering already included in the switchboard layout?

[@KrisSlyka]

Yep!, the switchboard does all the power filtering and in this case negative voltage rail generation.

[@janoshtrenhem3573]

@@KrisSlyka awesome, so I could just put a connector for a standard 9v pedal power supply on the board and have my pedal run of the socket (could swap it in for the 01x02 conn ?)

[@KrisSlyka]

@@janoshtrenhem3573 Yeah, that's how I did it in the video! Except with a wire on the 01x02 running to my lab power supply

[@janoshtrenhem3573]

@@KrisSlyka I had an interesting thought, maybe it’s something for you as well. Do you know the Friedman Motor City drive? It’s a tube driven pedal also using a 12au7/12ax7. In the sweetwater review of that pedal the guy mentions that this is one of the few pedals that actually hits the tube with 220v and that sets it apart from a lot of tube pedals, because only then the tube can operate completely. Did you ever think about doing this and can you tell me if it would even be possible? I thought about designing some sort of 9V to 220V switching power circuit that would fit into a pedal. And then hit the plate of the tube with that. Possible or bad idea ?

[@KrisSlyka]

@@janoshtrenhem3573 Yeah, I think that's absolutely possible. Some kind of small flyback transformer would probably work, or even a boost converter, though that will be much noisier. And since the current draw isn't particularly high everything should still be possible using relatively small components when running it at high frequencies. I've looked at some easy to use driver chips for this kind of stuff before and landed on the MIC3172YN, though I was only targeting around 50-60V.

[@miguelrichartmellado2834]

Me gustaria saber por qué no has incluido los subtitulos.

[@professionalhater2809]

Is it possible to use a nixie tube? And make the segments light up?

[@KrisSlyka]

That's a very different kind of tube, and no, not at these low voltages

[@ncuzdvarga4918]

How to add eq. Or tonestack? Thank's

[@danielmcfarlan1035]

Can i make something like this with a vacuum tube salvaged from an old radio?

[@KrisSlyka]

Depends on the tube! You might be able to find a 12AX7 or 12AU7 in one, but you'll probably just have to look up the tubes you have and see what you can do with them

[@Bleats_Sinodai]

I've been breadboarding with tubes since 2007, including high voltage. Just keep at least a row of clearance between connections on the breadboard and never fiddle with the connections while powered.

[@robertjohansson6027]

Hi my name is Robert. I'm playing around with a couple of different tubes and was wondering how you go about designing a circuit for them? Do you have any good way of calculating the bias resistor from the datasheet?

[@radzloko]

Its possible to add one copy of that circuit after that circuit so you have mor gain even with only 9v?

[@KrisSlyka]

Sure! Your headroom is just going to be pretty limited, so it won't get a ton louder, just more distorted. But if that's what you're looking for you'll definitely get it

[@radzloko]

@@KrisSlyka Nice! Thanks!

[@upside-down6211]

Can i use 6j1 valve ?

[@KrisSlyka]

Not as a direct replacement, but you should be able to build something similar with one.

[@ncuzdvarga4918]

How to add eq. Or tonestack? Thank's