In Reply to: Low DCR versus higher inductance chokes posted by xaudiomanx@aol.com on October 5, 2008 at 17:18:44:
If you want a straight answer, leave this forum immediately and go to diyaudio.com.There is a group here that views any DCR to be evil, rather than as a parameter which should be optimized to produce a well-behaved power supply. Think of DCR as the struts in your car's suspension - it provides the damping between the interaction of springs and vehicle mass (inductance and capacitance) as it responds to varying forces (currents). Too low of DCR, and the power supply rings at too high of a quality factor, and can add excessive color to the sound under dynamic load conditions (i.e., in a single-ended amplifier). Just like a car bobbing up and down with leaky struts, responding poorly. A low-DCR power supply for low-current applications might sound "full of life", but it's not necessarily the music you will be listening to. This can, and should, all be optimized via simulation - PSUDII is a good starting point. Too much DCR is a bad thing, but an optimized DCR can be of benefit.
For more information about filter theory for classical mechanical and electrical systems, check out Olson's Dynamic Analogies - one of the best references on this topic, and one of the most brilliant engineering texts I've encountered.
I'm surprised this debate has survived for so long!
BTW - the low-inductance in the LSES supply is something that I cannot take seriously, and is far more controversial than the simple low-DCR fad - it is not reasonable to expect input chokes below critical inductance to properly supply stable B+. A low-DCR power supply with sufficient L will perform well. The LSES as I've seen it described looks more like a bad cap-input supply with added resonances than it does a proper LCLC filter. I would not be willing to invest in building one.
Edits: 10/05/08
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Follow Ups
- RE: Low DCR versus higher inductance chokes - jon_s 17:47:04 10/05/08 (7)
- YeaaaaaBaaabeee! (nt) - wheezer 11:40:04 10/06/08 (0)
- Well said (nt) - danlaudionut 18:16:15 10/05/08 (5)
- RE: Well said - Ray Moth 22:31:21 10/05/08 (4)
- 200 to 1 - drlowmu 07:25:25 10/06/08 (3)
- so what... - PakProtector 08:25:50 10/06/08 (2)