12Ax7 Prototype Board

[BrownMagic]

Has anyone used the 12ax7 Prototype Board? If so, can you please share photos of your build?

I'm interested in getting an SMPS from C2C to try my hand at a Kinglsey type circuit. Not too worried about boxing it just yet, so it seems that the prototype board would be perfect.

But I don't see any mounting holes on the board and I don't see any info on what that's meant to be mounted to. The tube socket is board mounted, so I'm not sure how to mount this safely.

Thank you!

 

[thomasfrank]

Has anyone used the 12ax7 Prototype Board? If so, can you please share photos of your build?

I'm interested in getting an SMPS from C2C to try my hand at a Kinglsey type circuit. Not too worried about boxing it just yet, so it seems that the prototype board would be perfect.

But I don't see any mounting holes on the board and I don't see any info on what that's meant to be mounted to. The Geometry Dash tube socket is board mounted, so I'm not sure how to mount this safely.

Thank you!

What kind of Kingsley circuit are you hoping to prototype first? A preamp, overdrive, or something else?

 

[vigilante398]

It looks like the 12AX7 prototype board was intended more for breadboarding than for actual building into a box, thus the lack of mounting holes. Maybe if you ask @Robert really nicely he could make a compact one with mounting holes for building into boxes, because the lazy idiot running C2C can't seem to be bothered to do anything practical like that.

 

[BrownMagic]

It looks like the 12AX7 prototype board was intended more for breadboarding than for actual building into a box, thus the lack of mounting holes. Maybe if you ask @Robert really nicely he could make a compact one with mounting holes for building into boxes, because the lazy idiot running C2C can't seem to be bothered to do anything practical like that.

I wouldn't want to breadboard something run off an SMPS, so I guess these protoboard were meant for lower voltages then?

I was actually looking at the PedalPCB 12ax7 because C2C just ran out of their "King Nothing" boards. They've also been out of the Particle Accelerator boards. Did you have issues with C2C designs?

Alternatively, there's Frog pedals and their SMPS powered Alembic F2B. It would be easy enough to modify that into something like a Page.

Frog Tube Preamp 2.0 PCB for DIY – Alembic F2b style – Onboard Power Supply – FrogPedals.com

frogpedals.com

...Lol damnit I just read your signature

I really am looking for a 1-tube/2-stage preamp, but C2C only seems to have preamps with 2-tubes or buffers with single tubes in stock right now. Do you happen to have any other 1-tube/2-stage preamp boards in stock that aren't listed on your site?

Thank you!

 

[vigilante398]

I wouldn't want to breadboard something run off an SMPS, so I guess these protoboard were meant for lower voltages then?

I was actually looking at the PedalPCB 12ax7 because C2C just ran out of their "King Nothing" boards. They've also been out of the Particle Accelerator boards. Did you have issues with C2C designs?

Alternatively, there's Frog pedals and their SMPS powered Alembic F2B. It would be easy enough to modify that into something like a Page.

Frog Tube Preamp 2.0 PCB for DIY – Alembic F2b style – Onboard Power Supply – FrogPedals.com

frogpedals.com

...Lol damnit I just read your signature

I really am looking for a 1-tube/2-stage preamp, but C2C only seems to have preamps with 2-tubes or buffers with single tubes in stock right now. Do you happen to have any other 1-tube/2-stage preamp boards in stock that aren't listed on your site?

Thank you!

Looks like I forgot to update stock levels on King Nothing and Particle Accelerator, I actually have plenty of stock of both. Just updated those.

You need to be careful with high voltage whether it's inside a box or on a breadboard, but there's no reason you can't breadboard high voltage circuits, I do it pretty frequently.

 

[BrownMagic]

Looks like I forgot to update stock levels on King Nothing and Particle Accelerator, I actually have plenty of stock of both. Just updated those.

You need to be careful with high voltage whether it's inside a box or on a breadboard, but there's no reason you can't breadboard high voltage circuits, I do it pretty frequently.

Awesome! Frog pedals looked great, but I'd personally rather go with the more well known and documented brand, C2C, even if the owner is a "lazy idiot"

I'll definitely be picking up some PCB's. Thanks for updating the stock on site. Really glad I posted and caught your eye cause I was really disappointed when I thought they were out of stock.

Regarding breadboarding high voltage from an SMPS, I know you mentioned breadboarding in your HV daughterboard documentation, but I don't trust myself. I've been doing this 20+ years and I still make clumsy wiring mistakes. The fact that you have known and documented layouts that work safely gives me way more confidence than trusting my own frankenstein prototyping setups that I typically use for 9v pedals.



While I've got you, I had two questions...

Have you even experimented with different FET's in the King Nothing? I was wondering how a larger power MOSFET like the IRF520 would work, assuming I change the voltage divider to give it a higher voltage and I account for the different pinout/component size.

I was looking at the Ambassador preamp and it seems that the schematic shows the channel switch, but I don't see any references to it in the layouts or in the build photos that you have shown. Was there a change in design between the schematic and layout?

Thanks again! You'll be getting an order from me soon!

 

[vigilante398]

Have you even experimented with different FET's in the King Nothing? I was wondering how a larger power MOSFET like the IRF520 would work, assuming I change the voltage divider to give it a higher voltage and I account for the different pinout/component size.

I haven't, I've always just used J201 there, but there is no reason a high-voltage FET wouldn't work if you give it the volts it needs. Something like LND150 could be interesting there, I use those occasionally when I just need one more stage for a buffer or boost on an otherwise all-tube design.

I was looking at the Ambassador preamp and it seems that the schematic shows the channel switch, but I don't see any references to it in the layouts or in the build photos that you have shown. Was there a change in design between the schematic and layout?

The footswitch on Ambassador is a channel switch and as-designed it does not have a bypass switch. If you look at any of the gut shots you'll notice that the footswitch PCB has 9 pins to the main PCB instead of just the 6 used for true bypass. This doesn't explicitly show that it's a channel switch and not a bypass switch, but it's a good hint.