Category Archives: Electronics Design

Clean Squeeze – Hollis Flatline Opto Compressor

One of the first stomp boxes I made (and arguably my favourite so far) is the Hollis Flatline Opto Compressor. We amended John’s original schematic amended to show the topology a little more clearly: The first stage of the TL072 dual op-amp is configured as a non-inverting amplifier. Now, excluding the effect of the light… Read More: Clean Squeeze – Hollis Flatline Opto Compressor »

How to calculate the series resistor for an LED

So you’re mucking about with a stompbox and you want to change the boring old red LED for a shiny new white LED – but you’re not sure how to proceed… Over the last ten years or so, light emitting diodes (LEDs) have generally become much more efficient than they used to be (actually, the… Read More: How to calculate the series resistor for an LED »