68kMLA Classic Interface
This is a version of the 68kMLA forums for viewing on your favorite old mac. Visitors on modern platforms may prefer the main site.
| Click here to select a new forum. | | Choosing capacitors for LC 475 PSUs | Posted by: arroz on 2026-05-27 06:08:33
Hi!
I have 3 LC PSUs here (just my luck, all different, DynaComp, Astec and TDK). I'm going through the process of picking which caps to buy and my question is related to ESR. From what I understand, going for the lowest ESR available might not be the best option since PSUs may depend on the specific ESR of the original caps to work reliably and produce high quality output. The problem is ESR is not printed on the caps, and often no useful part number is printed also (even if it was, finding the data sheet of decades-old caps is next to impossible). I don't have an LCR measurer but even if I had, the values may be way off due to the capacitor aging.
Given all this, how do you pick which caps to buy for PSUs?
Thank you,
Miguel Arroz | Posted by: croissantking on 2026-05-27 06:24:56
Hi!
I have 3 LC PSUs here (just my luck, all different, DynaComp, Astec and TDK). I'm going through the process of picking which caps to buy and my question is related to ESR. From what I understand, going for the lowest ESR available might not be the best option since PSUs may depend on the specific ESR of the original caps to work reliably and produce high quality output. The problem is ESR is not printed on the caps, and often no useful part number is printed also (even if it was, finding the data sheet of decades-old caps is next to impossible). I don't have an LCR measurer but even if I had, the values may be way off due to the capacitor aging.
Given all this, how do you pick which caps to buy for PSUs?
Thank you,
Miguel Arroz
I understand the secondary side caps should be low ESR (also known as low impedance). The rest should be general purpose. Use good quality brand name parts rated to 105C.
Here’s a Mouser Cart for the Dyna Comp DCF353. | | 1 |
|