I’ve been looking at using an encoder as a front panel control. Encoders are industry standard devices made by ALPS, Panasonic, Bourns and CTS among others. They come with and without a push-button switch and (not-counting the switch) have three terminals, labelled A, B and C.
We can connect the C terminal […]
I came across Ian Johnston’s project to modify a Pioneer surround amp to incorporate a motorised volume control and decided to use his design as the basis for a small project. For his part, Ian hacked his design from parts he had available, whereas my design is fully realised and value engineered. […]
I thought I would make myself a crib sheet for the basics of designing with op amps. Then I thought I may as well post it here so I won’t have to remember where I put my crib sheet. This will be an ongoing thing.
The subject is: Analogue audio design using op-amps with single-ended […]
Update – extra schematics and timing diagrams added (see below). Also TLP222G optofets are available in the shop here.
Here are a couple of options for generating proper 48V phantom power from a 9V supply. Before we get stuck into the details I should point out that the quiescent current for the first option is about 27mA and for the second about 52mA, so don’t be thinking you can run this from a PP3/1604/6LR61 […]