On the subject of parts, if you don't have an 8 Ohm test load, I suggest you purchase two 4 Ohm 50W resistors and mount them on a heat sink or metal plate. It will be handy when it comes time to power up and test the amplifier. It can be done without it, but having a test load allows you to test the current source separately before connecting the SIT. It is better for peace of mind, and allows for less stress. 
It can then be used for testing the completed amplifier if you have a FFT rig.
Example of 4R 50W resistor
It can then be used for testing the completed amplifier if you have a FFT rig.
Example of 4R 50W resistor
Thanks for that parts list. The links to Mouser go above and beyond so much appreciated.
I think you said that you didn't actually build the power supply that you designed? So no parts list for that?
Ciatation19, I wouldn't say definitely no. However at start-up or during initial set-up, the voltage may be at power supply voltage until current flows. Once running, the voltage will be much lower, at around 33V. During setup, when the SIT is not connected and current is not flowing, the power supply voltage my be at the capacitor for the period that it is powered up. My power supply outputs up to about 65V or so under no load so I decided to err on the safe side. On the other side of the capacitor is my speaker.
If your power supply outputs less than 63V under no load, it may be doable. But capacitors can fail. For me, I value my speakers so I played it safe.
This is do-it-yourself so you are the master of your own domain.
I leave the decision to you.
If your power supply outputs less than 63V under no load, it may be doable. But capacitors can fail. For me, I value my speakers so I played it safe.
This is do-it-yourself so you are the master of your own domain.
I leave the decision to you.
Paul, My power supply was done nearly two years ago so no, it was not built on my just designed PS board. However what I built nearly two years ago fits on the board.
Here is the schematic. I have not included the AC circuit but that is no different from the typical power supply seen on this forum.
If you are going to use my PS board, you need to choose capacitors with 5 pins.
An example: 22mF 80V
Here is the schematic. I have not included the AC circuit but that is no different from the typical power supply seen on this forum.
If you are going to use my PS board, you need to choose capacitors with 5 pins.
An example: 22mF 80V
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It should work with no parts change. The alternates were originally suggested by Zen Mod in his Lazy Singing Bush thread (P-Channel Mosfets)
Thanks. D1 is just an LED to show that the power is on? I consistently seem to fry those either installing them backwards or having them underrated for the voltage they see.
Yes, the LED will show that the power is on. More importantly it also indicates that the capacitors are charged, so if you are about to work on your power supply, you can visually check before you dive in.
The LED has an appropriately sized voltage dropping resistor in series with it so overvoltage should not be a problem. The longer LED lead, the anode, is always connected to the more positive side of the circuit. In this case that would be the Ground side as the other side is V-. With my PS board, the long lead goes into the round pad (the pad closest to the resistor).
The LED has an appropriately sized voltage dropping resistor in series with it so overvoltage should not be a problem. The longer LED lead, the anode, is always connected to the more positive side of the circuit. In this case that would be the Ground side as the other side is V-. With my PS board, the long lead goes into the round pad (the pad closest to the resistor).
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