BuffTest PCB & Panel
$15.00 / Coming Soon
The BuffTest is an extremely accurate buffered mult with a clever little circuit that lets you turn it into a cable tester at the push of a button. It can also be patched as 3x manual gates and, if you can find a use for it, 3x negative gates. Bi-colour LEDs indicate voltage. In testing the BuffTest had a voltage error of under 0.03%.
Most passives are 1206 SMT, small enough to save space but big enough to solder by hand with a regular iron. If you haven't soldered SMT before this could be a good first module to try. ICs are SOIC, the buffer specs a TI OPA4171 for incredibly precise voltage following. Jacks are PJ301M-12 (Thonkiconns).
Following user feedback from the LRMSMSLR the BuffTest has a footprint for a shrouded power header if you'd like to build it with one. Reverse polarity protection is provided by a pair of diodes.
Front panel is PCB material with black soldermask and ENIG gold lettering. Secondary labelling is printed in the copper under the soldermask so it looks embossed which I think is pretty cool. Also lightning bolts.
The BuffTest is in stock and shipping now.
Schematic and discussion of the design: https://www.muffwiggler.com/forum/viewtopic.php?t=158717
270R x 6 (R1, 2, 3, 5, 6, 7)
1k x2 (R4, 8)
4k7 x6 (R14, 15, 16, 17, 18, 19)
100k x1 (R9)
200k x 3 (R11, 12, 13)
10M x 2 (R20, 21)
47pF x6 (C6, 7, 8, 9, 10, 11)
0.1uF x4 (C3, 4, 5, 12)
Capacitors (Al Electrolytic)
47uF x2 (C1, 2)
1N5819HW x2 (D1, 2)
3mm Bipolar R/G LED x2 (D3, 4)
OPA4171 (SOIC) x2 (U1, 2)
TL072 (SOIC) x1 (U3)
Momentary switch (E-switch TL1105LF250Q) x1
2x5 IDC power header (optionally shrouded) x1
PJ301M-12 sockets x8