This Week on the Breadboard: The Yankee ScrewDriver Deluxe Turbo

[Solder of Destiny]

3.4V might be close enough. Are you breadboarding or building a PCB? We can tweak R18 to dial-in the drain voltage.

Thanks. It's actually this stripboard layout I'm working from. I'll socket and test the 3.4 jfet when I get to that stage. I've measured all the N-channel jfets I have and that's still the closest I've got

 

[Chuck D. Bones]

If you have a breadboard, you can build just enough of the 1st stage to check the bias.

 

[Solder of Destiny]

If you have a breadboard, you can build just enough of the 1st stage to check the bias.

Hi again (and sorry again).

I had to raise R18 from 33k to 470k to get to a drain voltage of 5.5v on Q1. Does this seem outlandish? And is there a downside to ending up with this much higher value?

The other thing I'm struggling with is getting Q5-E up to your suggested 5.3v starting point. The highest I can get there with the trimmer is 4.1v.

 

[Chuck D. Bones]

Hi again (and sorry again).

I had to raise R18 from 33k to 470k to get to a drain voltage of 5.5v on Q1. Does this seem outlandish? And is there a downside to ending up with this much higher value?

No, 470K is fine. Even removing R18 is fine. No downside.

The other thing I'm struggling with is getting Q5-E up to your suggested 5.3v starting point. The highest I can get there with the trimmer is 4.1v.

This is not a troubleshooting thread, but let's see if we can solve this quickly. Did you sub any parts?
Measure these four voltages:
Q4-D, Q4-S, Q3-C, Q3-B

 

[Solder of Destiny]

No, 470K is fine. Even removing R18 is fine. No downside.


This is not a troubleshooting thread, but let's see if we can solve this quickly. Did you sub any parts?
Measure these four voltages:
Q4-D, Q4-S, Q3-C, Q3-B

Thank you for your forbearance.

I built it exactly to the stripboard layout attached (with the exception of the germanium transistor and the aforementioned resistor change).

Q4 (BS170). D =8.94v, S - 4.8v
Q3 (104NU71). C = 3.4v, B = 0.65v

 

[Chuck D. Bones]

OK, I see what's going on. When you find Vero layouts on the internet, you use them at your own risk. I found one error on this board in about 30 sec. There may be others. I'll let you compare that layout to my schematic. If the error I found is the only one, then fixing your board will be easy.

 

[Solder of Destiny]

I hear you, but I'm not very experienced with schematics so I take my chances. Let me try to figure this out (it's going to take me a lot longer than 30 seconds).

 

[~Tu3ePh0x~78~]

is there is PCB for this? I would like to have two (spare in case I mess up the first one)

Also curious about the HFD inspired build Chuck designed IIRC

Thanks for the great work you contribute to DIY!!

Dean

 

[szukalski]

If you're not in USA then this is an option:

Screwdriver Deluxe Turbo

Sounds like Skreddy Screw Driver Deluxe with mods by Celestial Engineering Q2 can be any low noise Si transistor. Q1 can be any N-channel JFET with Vp around 3V or so. Not all J112s will have the right Vp. I actually use MMBF4393. Adjust R6 for 5.5V on Q1-D. Adjust trim to taste (start with 5.3V).

sheepylove.com

 

[~Tu3ePh0x~78~]

sorry, I forgot I posted on this. I’m actually in the US. Can I get these PCBs through pachyderm pedals? Or at least pay exorbitant prices and tariffs? I don’t think I can live without this build….

Thanks
Dean

 

[~Tu3ePh0x~78~]

sorry, I forgot I posted on this. I’m actually in the US. Can I get these PCBs through pachyderm pedals? Or at least pay exorbitant prices and tariffs? I don’t think I can live without this build….

Thanks
Dean

just tried to buy this online and it let me put it in the cart, then said there was none in stock. Does anybody have a spare board they could send me I’d be willing to pay for it. I guess worst case scenario I could pay for another printing of the boards.

Thanks

 

[~Tu3ePh0x~78~]

If you're not in USA then this is an option:

Screwdriver Deluxe Turbo

Sounds like Skreddy Screw Driver Deluxe with mods by Celestial Engineering Q2 can be any low noise Si transistor. Q1 can be any N-channel JFET with Vp around 3V or so. Not all J112s will have the right Vp. I actually use MMBF4393. Adjust R6 for 5.5V on Q1-D. Adjust trim to taste (start with 5.3V).

sheepylove.com

could you start a small run to restock on your site? I would definitely buy two, and start shopping there for new projects as I notice there is a lot to choose from. My favorite pedals are from Skreddy and I want this particular circuit really badly. I wanted the Desert also but not quite as bad.

Thank you much for your consideration and contributions!

 

[szukalski]

could you start a small run to restock?

I'll put the SDT on the list for the next restock. But you're based in the states, right? That makes shipping a challenge..

 

[~Tu3ePh0x~78~]

I'll put the SDT on the list for the next restock. But you're based in the states, right? That makes shipping a challenge..

I can figure out a work around and pay extra for the PITA factor. I also want at least 3. What country does Sheepy ship from?

Thanks a million

 

[Chuck D. Bones]

Deutchland.

 

[cooder]

Deutchland.

Germanium.

 

[~Tu3ePh0x~78~]

Germanium.

hey, was Germanium discovered in Deutchland?
if it wasn’t for you guys, we would have only silicon to clip with