DT JFET Preamp

A project log for Audio Blox: Experiments in Analog Audio Design

A Project page to host and blog about my various analog audio circuit experiments and designs.

avrAVR 05/11/2016 at 22:5511 Comments

SO got another one for you guys today! The infamous Don Tillman JFET preamp is a design that has been kicking around the web since the early 2000s. I recall seeing it all over DIY guitar effects forums back in the day and even did a old design in eagle a few years ago but never fabricated it. Anyways I wanted to finally make a board and give it a shot, so here is my schematic and PCB:

First Route of the PCB:

All credit goes to Don Tillman for designing this preamp, I merely just copied the schematic to make this snazzy PCB. Check out his original page here:

Stay tuned for more folks!


Dave Wietzel wrote 06/17/2017 at 17:03 point

Bump...been working on a lot of projects. Did you ever get these PCBs made?

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AVR wrote 06/18/2017 at 01:31 point

Hi Dave, I have a few PCBs I built one but I haven't tested it, projects have been fallign by the wayside because of my new job and other projects taking priority. I guess I could sell you a PCB and you can have at it and do what you want trying it out, does that sound good ? PM me if you are interested. 

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Dave Wietzel wrote 06/17/2017 at 16:44 point

I have been working on several projects (Bassman, Dumble clone) and circling back to this. Did you ever get the PCBs worked out? Let me know :-) Thanks

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Dave Wietzel wrote 09/16/2016 at 18:12 point

Just checking in to see if you have any update. Thanks for doing this BTW...

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AVR wrote 09/16/2016 at 22:00 point

I got it 90% done, got a few other things to work on this week, but I should have it out to the fab by the end of the weekend. I'll post a link here in due time ;) 

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Dave Wietzel wrote 09/12/2016 at 19:04 point

Would you mind sharing the necessary file(s) for me to have PCBs made at OSHPARK? Have been looking a while for the Tillman PCB. Would appreciate it. Thanks

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AVR wrote 09/13/2016 at 16:45 point

Hey, I did share the files on github but I dont have gerber's available yet. I'm going to revise this PCB this week and fabricate it. I plan to sell PCBs on my Tindie store very soon!

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AVR wrote 09/13/2016 at 20:36 point

And it seems that the PCB is not completed in my Github, must have forgotten to commit it, sadly my laptop has been reformatted since then. I'm gonna do a new version of the PCB in KiCAD today and we'll see how it goes ;)

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AVR wrote 09/29/2016 at 06:11 point

Hey Dave, I ordered PCBs this evening, should be about two weeks until I have them. THey will be up in my tindie store.

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Dave Wietzel wrote 10/02/2016 at 22:34 point

Sounds great. How many did you order? I would like at least 10 and maybe more if it works out. Thanks!

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AVR wrote 10/02/2016 at 22:37 point

I got only a prototype run of 6 I'll be ordering a lot more if it works out nicely :)

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