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In the Forum: Melquiades Amplifier
In the Thread: About the pre-warming of playback

Post Subject: What about the loss angle: tan(delta) ?Posted by Axel on: 8/15/2009

I think what actually happens it that the dielectric, when it gets most fully discharged, simply takes some time again to get 'FULLY' recharged. The perode inbetween will make the loss angle (or power factor) become a lot worse. This means the caps' charge speed gets 'slower'. The bigger the cap, and the worse the initial loss angle, the more pronounced the problem. It would be similar to when an electrolytic cap starts to dry out. Maybe yours already are on this 'road' as they appear to live in a pretty hot environment most of the time.

More lately some (don't know the code right now) Siemens A.G. made electrolytic caps (hi-rel) have become available with a much smaller loss angle when compared with the more usual run of the mill polarized caps, it aught to help in our estimate --- yet there is more.
Since essentially the music signal has to go through these 'storage caps' all the time (therefore the noticeable degradations that may be noticed), it might be worth it to consider using not only just a few 'big' electrolytic to do the job, but make up a 'cap array' of various caps (smaller to bigger values) to reach the desired value. This way the loss angle should be improved, improving power supply’s performance.

Lastly, but I can not confirm this with the power supply caps yet, I have noticed that caps of approximately similar physical size and varying values work better when used in parallel I.E. the higher the Voltage to bigger the physical size matching to a lower voltage bigger value.
The more the physical size differs the more the chance winding up with incoherent sound. I'm sure there is some scientific explanation here, but I would like only to mention this effect I noted when working with foil caps in cross-overs.

Axel

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