I used a Electronics Salon/Audio Wind PCB-SP2-1 regulator PCB I bought on eBay for the regulator circuit. This is a really well made PCB that only cost several dollars from China. The PCB is normally supposed to provide +/- volatge from a transformer and LM78/79 regulators. But with some simple modifications, I was able to put 2 +15V regulators on the board and have 2 seperate DC rails.
I also used an additional LM7805 5V regulator to provide 5V for switching the amps into standby mode instead of just cutting power.
The biggest change is swapping the positions of 2 legs on the negative side of the regulator (since an LM7915 has swapped legs).
Here's the parts I ordered from Digi-Key
I was able to fit some large TO-220 heatsinks on the board, but had to trim them just a little to clear the capacitors and other close components. I used a grinding wheel and Dremel cut-off wheel (the larger EZ-Lock 1.5" kind).
Once trimmed I painted with flat black spray paint to make it look better (though putting tape over the spot the regulator would mate up)
Here is the leads out to each amplifier. I used one of the extra grounding holes for another ground wire.
Bottom view of PCB.
ON/OFF & DC Trigger
To handle the on and off, I wanted to incorporate a DC trigger to shutdown the amp when not in use. This uses a 2 switches and a relay. A switch on the back chooses between front panel and DC Trigger.
The amp doesn't actually turn off. I am using the SLEEP function. It works by applying +5V to the "Sleep" pin on the board. That mutes the board and puts it into a low power mode (still on, but less then idle)
I actually didn't understand the function at first as it is not explicitly documented. I thought I had to apply +5V to the +5V pin on the board. But that is a +5V supply that you could jumper over to the sleep pin.
I had already built the additional +5V LM7805 circuit, so I kept what I had as it works just the same
I added pins to the boards to make easy to use connections. The AudioWind SP2 has extra connections on the +voltage side for an adjustable voltage regulator. This gave me a nice interface sending the 19V input over to the ON/OFF board
I do not know the actual name of this type of pin, but they fit the jumper cables that are common in computers. I bought them at Tanner Electronics
in Carrollton Texas
Here is the schematic. A 5V LM7805 creates +5V which is used to power the Sleep pin on the Sure boards. If "DC Trigger" mode is selected, then this 5V is supplied by default, muting the amps. The 12V relay gets triggered by the reciever and cuts off the 5V supply to the Sleep pin and the amps come alive.
I made the 5V circuit by hand, so it wasn't as nice looking. I then painted it black to make it less obvious
The chassis is a BUD Industries AC-424 Aluminum Chassis, 12" Length x 8" Width x 3" Height
What I did was put the Amps on top of a hobby PCB to simulate the thickness of aluminum bottom of the chassis. I then measured how high that was (in milimeters) and used Microsoft Word to make a rectangle the fit the dimensions of the RCA spacing between each other and from the ground. I printed the label and drilled out the holes.
I did similar for the binding posts since the ones I bought had built-in spacers.
I used JB Weld to attach the stand-offs. Tighten the stand-offs to the boards. Slater on the some JB Weld to the bottom of the stand-off and then place it where needed. Use a toothpick or similar to spread the JB weld up the sides of the stand-offs and around the chassis.
Covered the tops of the stand-offs with painters tape and then painted it white using spray paint from auto store (its better quality then Krylon, but not as thick per coat).
I again used the laser shipping labels to print out labels for the terminals. I applied a clear coat after applying the labels to protect them and prevent from peeling
I had a glass top cut for the lid. It was $16 at a glass place called Ajax Glass
. They also drilled holes in the glass to line up with the holes in the chassis and they rounded the edges of the glass
I used speed nuts or U-nuts to attach the glass to the chassis. I also painted a 1" border on the underside of the glass (using painters masking tape) to hide the speed nuts and top of the chassis. The thickness of the speed nut also raised the glass slightly off the chassis so that air can exchange with inside the chassis to vent off heat.