"Open" is really gaining traction

[Renegade]

We had open source software, and the hardware community is really jumping on board. Here's one project:

http://www.electrosmash.com/1wamp

1Wamp Electric Guitar Amplifier - Open Hardware

1Wamp is a one Watt small guitar amplifier based on a JFET guitar pre-amp, the Big Muff Pi tone control and the LM386 power amplifier. This portable amp is an open hardware project designed by ElectroSmash using only free and open-source tools.

More at the link.

It seems like there's a very strong movement going on.

I'm just posting as this has been going on for a while, and it is continuing to go on in more and wider ways.

[40hz]

Nice! I think I recognize that preamp. Looks like a slight mod of the elegant and great sounding Tillman Preamp circuit. (See below.) Doesn't get much better than that AFAIC.

[attachthumb=#]

The kit price is a little expensive @$58 USD IMO. But it's easier than chasing down the parts if you don't have any of them sitting in bins around your workshop. The PC board on the other hand is a very good deal. I just might order one of those. Cancel that. The kit includes the plexi covers! That is a very good deal.

Thx Ren!

[Edvard]

*Grumpy mode engaged* 
I never understood how the Tillman was all that different from any of the other "cookbook" FET circuits out there.  In fact, the Tillman was designed for the J201 and won't work as well with many of the more common, but lower gain/higher current FETs like the MPF102, 2N3819, 2N5458, etc.  ...AND if you've worked with FETs at all, you'll know that each one is slightly but appreciably different, and stock resistor values must be tweaked for maximum performance (though the ones given may get you in the ballpark).  Add to that the concepts of diode biasing, CC loading, "cascode" chaining, ad nauseum, you could be tweaking for days... or maybe it's just that way for a hopeless circuit tweaker like yours truly. *Grumpy mode abated*

Also, the LM386 just doesn't do it for me as a guitar amp power section.  1 watt in a convenient DIP-8 package is novel, but give me 5-20 watts minimum.  Here's a trick: look in your old computer parts junk box and find an old ISA soundcard with a TEA2025 (2x2.5W) or a SoundBlaster16 with a TDA1517 (2x6W).  De-solder the chip off the board, wire the Tillman/Muff output to both inputs, and put a speaker on each output (paying attention to the official Data Sheets, of course) for a low-power 'twin' with MUCH better sound specs and power handling and no additional cost.  The TEA2025 can even be bridged.  Yeah, yeah, I know, the LM386 costs pennies, but hey, mo' powah, mo' fun!... 

As far as the 'Open Hardware' concept, it's so far worked for the Arduino, and a whole list of others.  Read up on Open Hardware at Wikipedia: https://en.wikipedia.org/wiki/Open-source_hardware

[40hz]

^Bad day huh?

re: Tillman.

Wire one up and give it a listen if you haven't already. Tweak it a little just for kicks while you're at it. Compare the sound and roughly 300 hrs of battery life to some of the more "improved" circuits out there.

I did. And the Tillman is all I'll use. Cheap, good sounding, and I enjoy screwing around finding the best sounding J201 and component values. I just do them up for myself and friends so it's not like I need a high degree of repeatability since I'm not manufacturing in quantity. Besides, it only takes about 5 minutes to put a Tillman together.

As far as the rest goes, the journey is the bulk of the reward with this sort of DIY thing.

If you just want a powerful ultra small amp go buy a Hotone micro. They come in several different models, each with its own signature sound, and run between $100-$150 street. They're great little amps with full tone stacks, and a lot of input and output options - including an effects loop. If you just want to shop bang for the buck and get a micro amp, a Hotone is the only way to go.

https://www.youtube.com/watch?v=gk9aoTFUFbo

https://www.youtube.com/watch?v=6pcBGH8ZDs4

[Edvard]

^Bad day huh?

Meh, working overtime lately.  I like the paychecks, but losing time for home and family just doesn't sit right after about 3-4 days of it.

re: Tillman.

Wire one up and give it a listen if you haven't already. Tweak it a little just for kicks while you're at it. Compare the sound and roughly 300 hrs of battery life to some of the more "improved" circuits out there.

That's just the point; I have.  I've designed my own effects, remember?  I always knew it from the circuit 'cookbooks' and data sheets as a part-for-part analogue of a standard common-cathode tube pre-amp (with different part values, of course), I just never knew it as a "Tillman" until I stumbled across the webpage.  By that time, it was old hat to me and it just seemed strange that some guy putting his name on it somehow made it so magical that all the stompbox and audio forums started calling it that.  Hence the grumpy, my apologies.

Speaking of Open Hardware, I remember some guy who was designing an open-source video card, and even had a few prototypes made, I wonder what ever became of that?
*edvard searches internets...
Aha! -> https://en.wikipedia.org/wiki/Open_Graphics_Project

[40hz]

^Um...I do remember  you do your own effects. We corresponded on that via PM not that long ago. I haven't forgotten. 

And in Tillman's defence, he never called it a 'Tillman' Amp. He's never called it anything but a Discrete FET Preamp. Nor did he ever claim (or even infer) it was an original design. Even on his own website. That "Tillman" moniker is something the music sites and musician rags started calling it. Probably because it has a better "ring" and is much more memorable than Tillman's own mouthful of a name for it. 

[Edvard]

^Um...I do remember...

Aw man, the grumpy really must have gotten to my brain Again, my apologies.
Yes, I was aware of all those things, and yes, "Tillman" rolls off the tongue better (like "Thermos" instead of "insulated beverage container"?), but I wonder why his design went viral and not all the ones that came before it?  A strange beast, this internet...

EDIT: Nevermind, I just read his website again and caught that he'd posted it on Usenet circa 1995.  So I guess the props really do go to him for popularizing it, and I was just late to the party thinking it was somebody else's birthday >_<