The ebay Chinese seller speeky zee Engrish poorly. Welding? Restaurant? Cattle?
I wonder why they say this low power amplifier needs a 30W power supply and I wonder why you bought a 50W transformer. 2W would be fine.
Because, as specified by the title, it was my first project in a while. Also, I went for what was available in the store. I had the option between 10 and 50 watts. Went for larger since 10w was in the low range.
You are probably right and a much smaller transformer (10W 36V) would have done it. Stupid me, I went with what was specified by the seller.
Maybe should I reverse engineer the board next time?
Put a fuse between the transformer primary and the live/hot power input. 100mA T type will do. Your power switch should switch the primary side, be in the hot line, and after the fuse. However if it's that toggle switch you need to make sure you sufficiently insulate those terminals. Personally I think that is too close to the board. Consider using a small rocker switch either on the rear or the side of the unit instead.
No need for the voltage clamp - it looks as if the board includes its own voltage regulators. You should also be OK without shielding, but use screened cable for your RCA jacks.
The TPA6420 says 1.5W. I do see a L7815CV and a L791515CV. So 10 watts should be enough (100mA works then).
From what I can find, T type are fast blow, am I correct? There is 4x4300µF
Elna RJD capacitors at the input of this board. Won't those blow it?
Not arguing with what you said, simply trying to learn. The board's power input appears to go through 2 100pf caps, then a diode bridge, then the 4300µF caps, then a combo of L7815CV and L7915CV. The caps are rated 25V, the
regulators says 36v max in absolute maximum ratings.
Now, I have no experience with transformers, but I have a 48V centertap 6.7A transformer here, and when I disconnect it, I had a peak going all the way up to 168V on my multimeter.
Wouldn't that damage anything?