mike williams flames

THE AMPLIFIER - its a big-un.


Here it is then, 500W rms per channel (Stereo), two input channels, each with volume,treble,bass. Switchable EQ and Mono/Stereo on each channel. Led bargraph power display (behind the smoked window).
The big red indicator on the left is the temp warning/cut-out.
The blue boards are (expensive) fibre glass prototype boards. I could not justify the cost of PCBs, so I used these for the Amps. The smaller board is the othere supply module, and the small brown veroboard is the anti-thump and speaker protection board. The handles on the top are nice stainless steel (from an old kitchen) and go over the two fan vents. The fan vents came from an old DEC PDP11 psu. The reason the handles are here apart from looking good, is to make sure that a glass (of Beer) cannot be stood on top of the amp (BANG!) On the left you can see the pre-amp and input selectors. The board in the middle carries two bargraph driver chips and the ten leds (for each side) that indicate power output. You can also see the relays that switch the speakers in (recovered from and old Jaguar XJ40). In the middle is a very big toroidal transformer that powers the beast. It should have cost well over 100, but by a real stroke of luck, I picked it up on Ebay for 12.00. Thhe bank of smoothing caps behind it cost more than that! The shield over the transformer helps to reduce mains hum, and in fact, there is none. Two fans, recovered from two dead PC power supplies. I picked up some hefty heatsinks on Ebay for 7.00, upon which the power transistors are mounted. The fuses are the plus and minus 70v lines to each side, with leds to indicate that the fuse has not blown. The RCA panel is just a useful addition - Left and Right in, then straight out again. The reason I added it was that I may take a cable from here to my lighting controller.

With more to come ... major rebuild during 2015--sounds amazing!

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