Here is the input buffer I built. It is based on the Cornish buffer, with some additional power filtering and some minor part substitutions.
The enclosure is a Bud CN-6702 from Mouser. No LED, no bypass, but there is room in the enclosure for both if you decide to build one. Paint is Rustoleum hammered spray. I think it came out pretty good for my first hammered finish.
I actually thought I had all the parts for this build, but it turns out I did not. I was short a couple of odd value resistors, so I made my own. Here’s a little tip. Let’s say you need a 7.5k resistor, and all you have is a 6.8k resistor. Grab yourself a small file, and start filing a spot in the middle of the 6.8k resistor. Once you break through the enamel, you will hit the actual resistor. Connect your multimeter’s test leads, and continue filing until you reach the value you need. When finished, cover the filed spot with clear nail polish. Works like a charm!
Here are the project files. Included is an ExpressPCB Schematic and PCB file, along with a PDF ready-to-transfer image. BJT Buffer – Schematic, PCB, Toner Transfer [ZIP]
Questions? Comments? Criticism? Compliments?