The (lack of) diodes to VDD are the reason the design is capped at 13.5V.
Must be too outdated then.Then we need at least a 12v Power Supply Unit and preferably not above 13.5v (because above of that the Lepai zenner diode for protection will reduce it, and will be useless, and some users reported that sound quality decreases). The higher the Voltage supplied, the more power will be able to output the amp, so 13.5V are desirable.
Hi guys, first time posting here!
I bought the amp last week, and already started modding. There was just problems and problems for me... luckily I managed to find out what happen just today.
1) Change all the caps to low ESR Panasonic caps, these are really good and value for money!
- Powercap from 3300uF to 5600uF+0.22uF and soon to 2x(5600uF+0.22uF)
- 2.2uF input caps to polyester Wimas MKS, was deciding between EVOX or Wima! any1 knows the difference? The MKPs are just too huge, smaller the better for me
- 1uF caps to polyester, hard to find low ESR for these so polyester the way to go
- Removed diode D2, I really thought it was a stupid diode.
Already sound pretty good here!
- Both op amp to OPA2132... ugh the decision between AD823, took the burr brown one due to low current req in the end anyone recommend otherwise?
- Add solder and reflow every joint for through pin and SMD components, the joints are of really bad QC
t!
Couple of points; 'genuine' 2.2 uf Wimas are Huge things