I need to have a good think about what I am doing here or rather how I am doing it. How the unit is to be constructed taking into account; cost of construction, cost of purchase, the cost of components, time spent to construct, installation, testing, fault finding, servicing and repair. At the moment there are problem areas that need to be addressed
So I’m going to drop off the horizon for a bit while I just sit and stare at the thing and breeze through catalogues; always a surprisingly helpful way to find solutions to problems – it’s a bit like wandering round a good hardware store. In the mean-time here are a couple of photos from my notebook to give you something to look at.The first image shows a sketch of the system as a whole. Since then the knob layout has changed and the proportions of the amp cabinets are different being wider and the lower battery pack also higher. Plus I will not be using any ports within the loudspeaker cabinets as I don’t like the phase shifts they entertain. The second drawing is a birds-eye view (looking down through cross-section) of a front panel knob with the MDF front panel cross-hatched and the knob shaft running through it. Since then I have decided to make the knob itself from large diameter (approx. 25mm) plastic rod. There needs to be a connection rod to connect the front mounted knob to the rear mounted switch/potentiometer anyway so it seems right to incorporate the two. The connection rod would normally be made from aluminium and cost about £6. Polished plastic rod will be better sonically (fewer metal parts with their associated magnetic fields), be cheaper to manufacture and I believe should look rather good. I’m even thinking of illuminating them in such a way that the power-switch/input-selection-switch/volume-control positions can be seen at a glance; different coloured LEDs pointing into the shaft with green/red for power, red/orange/yellow/green/blue/white for the six inputs and variable brightness white for volume. If I do use illumination I will make it so it can be turned completely off at the push of a button. But this is all more cost so maybe for the upper amp levels only.