Tweakers' Asylum Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ.

---

[ Follow Ups ] Thread: [ Display  All  Email ] [ Tweakers' Asylum ]

---

[ Alert Moderator ] [ Edit ] [ Delete ]

---

Experimenting with Power Supply Filter Caps.

166.82.238.65

Posted by Clayton Oxendine on July 8, 1999 at 20:48:53

I am through messing with my speakers, so in getting a little bored, I decided to either improve or blow some extra stuff I have around. First thing I decided on was a Onkyo DX C320 6 disc CD with a 1-bit DAC that was gathering dust due to my vinyl re-birth. I got out my collection of old C-Band receivers to salvage parts from. The Onkyo surprisingly has a filtering choke in the power supply which I attribute to the smoothness of it. Yes a mass-market can sound smooth. You must bear with me on my use of terms because I am not a EE. The power supply had two filtering caps. I did not have on my reading glasses so I can not tell you the manafacturer of them. One was blue colored and the other brown. The blue one was 4700 uF, and the brown one was 2200 uF. Before I go any further I will note that already I have noticed that in the critical places most caps seem to be black and in the non critical places, they seem to be blue. Is that coloring for tolerence purposes? Anyway, I salvaged a 4700 uF and a 2200 uF from my collection and paralleled them with the two existing caps. To not do too many things at once so I could desern the differences, the only other thing I did was to put some of my favorite damping material, which is foam underlayment for Wilson-Art Laminated floors, between the metal bracket that holds the circuit board, and the DAC and clock IC. I put everything back together and fired it up. Played it a while without listening so it could break-in some as the caps had not been used in years. When I sit down to listen, the first thing I noticed was bass. It had bass. Not bloaty bass, but tight bass. The output was obviously more also. To make a long story short, it sounded like a much more expensive CDP than what it is. I just can't get over the difference. Is this all mass-market's need is just some power to sound light years better? The caps I used with it are S.M.E caps and they are black. Anyone familiar with these? Got them out of a old Uniden 7700 receiver. But the story does not end here.
I have a Creek OBH-8 phono pre-amp which is not bad for $199. I thought, hmmm..., I'm on a roll. All I need to do is to double the filter caps on this. I did not have anymore of the S.M.E caps so I used a Marcon 35V 2200uF cap. Went through the same deal with letting it break-in and sit down for a listen. Bass was bloated and midrange seemed recessed. I am thinking, why did this not work? This is a cheapy too. It sould have improved it. I thought that maybe since the brand of cap was different, that maybe that was the problem. I did not have anymore of the S.M.E caps, but I did have 3- 80 uF Solen poly caps from a tweeter resonace circuit that I did not need anymore. Together they would only total an extra 240 uF's, but they are about the size of "Dixie" drinking cups. I paralleled them with the existing electrolytic and went through the same burn-in. When I sit down this time, the difference was even greater than with the CDP. The output was cleaner and it was like a veil had been lifted. Much more low-level detail. I just got some virgin LP's the other day. One of them was Patrica Barber's "Cafe Blue". With the new caps, it seemed like any decay of the cymbals or anything else just went on and on. The bass got stronger and tighter. Sounstage deepened. Here again, it sounded like a different pre.
Now what I want to know. Have I stumbled on to the difference between mid-fi and hi-end. Is it all in the power supply filters? I just can't believe they should make that much difference. But I am two for two in getting dramatic improvements. In my opinion, they are jaw dropping improvements. What I am going to do next is to get a 50W 24V DC power supply to replace the 6W cheapy that comes with the Creek. I am getting seriously into this tweaking that my wife is looking for a straight jacket to fit me. Now for my disclaimers. Do not try this because it seemed to work out so well for me unless you have something that if you boo-boo on it, it will not make you cry. I have no idea how many mid-fi components that would benifit from this. I do know now that certain caps work much better than others. Now I am going to replace the output cap in the CDP with a poly film to see what a difference it makes. I don't see how it can be on the magnitude of the filtering caps. Now I have to make a new case for the circuit board for the Creek. For you that are familiar with it's size, the 3 poly caps won't fit in it. What am I saying, they won't fit in any pre-amp case.

Clayton

This post is made possible by the generous support of people like you and our sponsors:

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2025, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---