No, not the Jeremys Paxman or Clarkson, but these:

Elma K1 knobs

Elma K1 knobs

They can be had with 4mm or 6mm shafts suiting both the 4mm shaft of the 2 pole 6 way Elma switch I got from HiFi collective I’m using, along with the 6mm shaft of the Vishay 50k logarithmic rotary potentiometer I got from Farnell.

Here’s the amplifier with the dimple knobs in situ:

Knobs with dimples

Knobs with dimples

I bought these from 4most electronics, who have a stock now of 19 of each of the 6mm and 4mm dimple and dome type.  Their website is bit out-of-date, but they are the main distributor for Elma (including audio quality switches) in the UK.  Haydn has been very helpful to me, so I recommend you contact him directly.

This might sound like a bit of paid advertising, but it’s unpaid; one of the hardest things I’ve ever found about DIY HiFi is finding hardware that looks as good as the circuitry sounds.  And finally, I think I’ve achieved it thanks to their kind help!

A long time ago in a galaxy far, far away….

i.e. about 25 years ago, while at uni, I got into Hi-Fi, and built my own speakers and amplifier.  I can’t remember much about them as I sold them to a friend, and went on to purchase off the shelf kit.

At the turn of the millennium when I was still single, without kids but with time and cash to burn, I picked up my audio electronics hobby with an aim to build the best pre-amp, including the best RIAA photo preamp I could:

My OTT preamp

My OTT preamp

It had (has)

  • balanced input for the phono
  • balanced output to feed my Chord power amp
  • self-designed RIAA filter
  • top quality components
  • OFC wiring throughout
  • completely independent left and right channel power / circuitry
  • a PIC16F84 controlling buttons (3 – source, mute and tape!), relays switching the inputs and a 20 x 2 LCD display showing what was playing (eg “phono (muted) -> tape” – and to avoid noise, it shut down after each button press has been handled – all written in assembler.
OTT preamp internals

OTT preamp internals

It was completely designed by me including schematics, layouts and I made the PCBs.

It was completely OTT, but it worked like a dream (and still does); I took it and my Wilson Benesch Full-Circle record player to Doug Brady in Warrington when shopping for some speakers, and they were amazed at the clarity and accuracy of the sound it produced.  Sadly the speakers are long gone, ebayed to pay for Phoebe’s tuition, but the preamp lives on.

But what’s always let me down was the case: just a big black box completely out of keeping with the rest of my (now aging) HiFi kit.

I’ve always wanted to tart up the preeamp, but never got round to it – until now.

What’s this got to do with the Raspberry Pi, you may ask?  Virtually nothing – except for one little detail: I was on a hunt for a more snug Raspberry Pi case for Chloe and google images threw up this link!

The moss dropped off and the stone started rolling…

This is just a rehoming project and won’t be related to the Raspberry Pi in any way, but I thought I’d post in case anyone out there is interested!