Ursa Minor - Free Boards

[smallbearelec]

Here is the pre-production prototype:



The layout is exactly the same as the perfboard version:

https://www.smallbearelec.com/Projects/UrsaMinor/UrsaMinor.htm

with two exceptions:

--I added jumpers to select either the usual single-transistor implementation or a two-transistor darlington
--Similarly, jumpers allow selecting one or two diodes in each leg of the clipping loop.

Re the selection of transistors: IMO, high-gain devices are way better to make the diodes break over. I don't hear much diff between vintage silicon and modern TO-92, but I do hear a clear difference between silicon and germanium. Of course, the configuration of the diode loop matters A Lot. Tweeker's paradise, and the parts cost pennies.

I have nine of these boards, and I will include one with each of the next nine orders for a Bare Box #1. Be aware that they are "Bare Bones," so you have to do the cutouts yourself.

Also please note: Until Labor Day, each Bare Box will also come with a 60x60 pad-per-hole perfboard.

Happy Summer Construction!
SD