I noticed that my T1 would occationally cause my speakers to make a nasty loud crackle pop noise after shutdown or right after I turn the T1 on. After I adusted my SMPS to the lowest setting the pop stopped. Must have something to do with the softstart relay?
It is only to have some safety margin, other parts have lower max voltages than those caps. If you use 4 ohm speakers the sound quality will suffer because of current limiting when the current gets high and running at high voltages, 28V is enough to reach max output for 4 ohms speakers.
If you have 8 ohm speakers then it shouldn't be a problem running at 38-39V, but if you run it very hard you should keep an eye on how hot the heatsink gets.
Just bought a T1 and a 38V SMPS300R.
My understanding is that you recommend turning the voltage down to 35-36V even though the AMP is rated at 24-39V. The obvious question is why? I assume the AMP provides the most power when supplied with the maximum input voltage (39).
Does fidelity suffer if the input voltage is too high? Are there components on the board which are close to their limits at 39V? My T1's power supply input caps are 63V, so that shouldn't be a problem.