April 13, 2016 Leave a comment
All right, no more moaning about lack of build time (at least not for now😉 )
Managed to do a little work on the mechanics of my “JLH evo” concept allowing you to get an idea of what the end result will look like (when it’s eventually finished…).
I’m still figuring out a final chassis design so I may well leave it in this state for quite a while, but at least the mechanics seem to fit together as planned and there’s enough room to run the wires. The baseplate size is app. 170 x 230 mm per mono block.
The extra PCB is a CRC-regulator stage that I will add to reduce the noise and ripple from the switching PSU (a Mean Well EPP-150-27). The advantage here is that the ripple frequency from a switching power supply is very high (typically 65-100 kHz) so the attenuation is much, much greater than at the normal 100/120 Hz ripple from a linear supply – meaning in other words that it’s possible to get away with much smaller filtering caps than a usual class A amp.
This should therefore reduce the highish app. 240mV ripple that’s specified in the data sheet for the supply that I am using down to something much, much less. Any HF-noise on the output should be well attenuated as well. Not sure what effect it really has but that’s part of the experiment😀