Many many (many, many!) years ago, around 1974? I built an integrated amp, the circuits mainly came out of magazines (I didn't design nuffink), the pre-amp sections were from a 1972 Wireless World project (op-amp based), the power amps from Practical Electroncs. It was really good, I thought. Unlike most of my other stuff to date, it at least worked properly, and was finished quite well in a nice "case" hand made from aluminium sheet (could order it cut to custom dimensions in those days), then few months or a year or so later I totally buggered it up by adding "extra features", like a loudness control pot, scratch and rumble filters, channel reverse, mono-mix (too much looking at Hi-Fi mags!), which with the input selector needed two banks of latch button switches (I was hitherto using like a Lorlin rotary switch for the selector). It was pants after that, and had an intermittent, one-channel-going-silent fault that I could never trace. It was eventually torn down. In the process I found the culprit, a dry joint on one of the blasted latch button switches (which until then had been impossible to access while still in situ). All of the parts either got lost or reused for something else. And then lost.
This is revisiting the power amps (only), but with a few "improvements" e.g. we'll have another go at MOSFET o/p.
Today I was making a more serious start on actually mounting stuff in the case (involves drilling holes!). Most parts direct from China via eBay.
NB: the mains switch is on a bit of Veroboard because I wanted a dual pole switch, what comes with the case is a single pole. This required me to get creative with alternative mounting means.
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- Had to open out the vol pot hole a bit but the very nice solid aluminium knob goes straight on the shaft.
