I was discussing my whole refurbishment plans with a friend and he sugested I should take lots of pictures as I go along and post them. I don't usually bother with pictures and just get on and do it - but this time I have taken pictures
So, yesterday I started the refurbishment. I should add that the intention here is not to inherantly alter the Yamaha design in any way, just to tidy it up.
First thing was to take everything out of the cabinets:
Taking out the mid and tweeter. The wiring is the original used by Yamaha; this has oxidised in parts and will be replaced.
Close up of the back of the tweeter. This shows it wired in reverse phase (+ wire to - terminal), this is the correct way.
Close up of the back of the mid driver. This is wired in positive phase, which is also correct. Note the enormous magnet assembly and the rear can making this a sealed unit.
The cabinet with bot mid and tweeter removed. The cabinet is screwed and glued chipboard with beech battens and plywood braces.
Close up of the mid removed. You can see where Yamaha have taken the cabinet cut out for the bass unit and screwed and glued it to the back of the cabinet for reinforcement. The picture also shows the extra cutouts to allow the cables to exit neatly from the drive unit.
Taking bass driver out (sorry it's a bit out of focus). This is also connected in positive phase. All drive units have case aluminium chassis.
Bass driver removed. You can partly see the horizontal plywood brace that is positioned between the bass driver and mid/tweeter section of the cabinet. There is also a vertical brace on the front panel between the mid/tweeter and adjustment pots.
Adjustment pots removed. You can see the copper shielding. These are going to be removed completely and replaced by fixed resistors. The holes will be filled in and laminated over.
Crossover removed (sorry again for this being in poor focus). This shows the replacement polypropylene capacitors tagged on to the original crossover. The old capacitors have just been electrically disconnected. This crossover is going to be binned and the pars are going to be moved to a custom built external
Just starting to sand the surface of the cabinets and fill the little dents left by previous owners. Originally these speakers were black and somebody, in the past, has tried to sand them back to a wood finish (which hasn't really worked). I have also removed (they are screwed in place) and filled in the speaker grill mounting sockets. This is only the first round of filling - two more to go probably.
Trial templates new gaskets, made fromm 3mm acrylicfor, sitting in the laser cutter.
The trial gasket templates tried for fit in the cabinets (the real gaskets will be laser cut from 1mm neoprene sheet) - very pleased with this. The one for the adjustment pots isn't actually going to be used but the file will be used to cut out the blanking plates.
Blanking plate trial fit. Made from two 1.5mm layers of Aeroply that have been glued together and cut to size with the laser cutter. These will also have MDF plugs glued to the back of them and then glued and filled in to the cabinets.
Replacement badges I have made for the front of the speakers. The one on the left is made from violet tinted acrylic with the writing laser etched on the rear. The middle one is made from brushed aluminium and the one on the right is transparent acrylic.
More pictures on Monday...