I occasionally read praise for DC link capacitors in power supplies so I bought them to try. What interests me is which is the optimal position first, second or all? What are your experiences? Have you tried different brands and which one did you like best?
My amplifier is 7n7 driver and PSE 2 x 6e5p (I also have the option to put 2 x 4p1l, but I haven't used it for a long time).
Power supply is LCRCRC.
Bert regards
Slobodan
My amplifier is 7n7 driver and PSE 2 x 6e5p (I also have the option to put 2 x 4p1l, but I haven't used it for a long time).
Power supply is LCRCRC.
Bert regards
Slobodan
The DC Link capacitor has good mechanical structure (stacked, not wound) and it has low inductance.
The 1. Cap (rectifier cap) must handle high impulsive current and large voltage swing. This is exactly the position for a DC link, so you might begin with this one.
But the good mechanical quality is useful in any capacitor in an unregulated supply. It's best to try it in all positions and take a long listening time for each one, IME.
The 1. Cap (rectifier cap) must handle high impulsive current and large voltage swing. This is exactly the position for a DC link, so you might begin with this one.
But the good mechanical quality is useful in any capacitor in an unregulated supply. It's best to try it in all positions and take a long listening time for each one, IME.
Hello there,
I strongly suggent:
Panasonic EZPV- EZPE
Vishay MKP 1848 - 1847
😉
I strongly suggent:
Panasonic EZPV- EZPE
Vishay MKP 1848 - 1847
😉
Aren't PSU filter caps generally in the 10s of thousands of uF whereas DC Link caps are in the 10s of (maybe a few hundred) uF? So how can DC Link caps be used in a PSU? (I clearly have a gap in my knowledge here.)
That's for solid state low voltage amps, not for valves. Valve amps, depending on several factors, can work well with 200uf or less.
I use DC Links for the first and last cap. Usually CLCLC. So electrolytics in between, as high a value as you need. First cap is usually around 15uF, last cap the same or bigger.
I use Kemet C4AQ because they're available from RS. A 75uF is excellent for a cathode bypass and these are in stock. A lot of values aren't.
https://uk.rs-online.com/web/p/film-capacitors/1744358?gb=s
I use Kemet C4AQ because they're available from RS. A 75uF is excellent for a cathode bypass and these are in stock. A lot of values aren't.
https://uk.rs-online.com/web/p/film-capacitors/1744358?gb=s
I am using 2x Kemet C444U 500 uF 900 V DC links in the first position of choke input 800 V power supply. 1 mF is required for damped supply operation. The size is the same as equivalent electrolyte capacitor would be (or even less), but they are PP metallized capacitors. Their characteristics are simply amazing: equivalent DCR in milliohms, equivalent inductance in nanohenries, voltage rise time 7 V/usec, peak current over 3,000 A, ripple current 50 Arms, according to data sheet. They are rated for high frequency, ripple current rating is at 10 kHz.
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First time I hear about damped supply. Will read about it.. do you have a source with more info? Thanks!
Choke input supply has ringing response (in LC tank of the first choke and first capacitor) to load transients. This ringing can be snubbed by adding resistance to the resonant tank. The resistance consists of transformer secondary DCR, choke DCR, rectifier forward resistance, and additional resistance in the rectifier circuit (added on purpose for damping purpose). Jim Hagerman has a calculator for minimum value of the first capacitor for given DC resistance.https://www.hagtech.com/choke.html
Sorry PS is CLCRC.
I have 12uF Epcos 1300V, 4pcs. 40uF Kemet C4AE 900V, 2pcs. 40uF Vishay MKP1848 900V and 2pcs. 40uF Epcos 900V.
My plan is to replace the first cap and put 40uF as the first, listen and then 2x40uF and listen. Same procedure with the last one. Should I combine them?
BTW, there are Iskra made in Slovenia DC link capacitors KNG2047 that are equivalent to Kemet C444U, although somewhat larger in size. I saw them dirt cheap, something like 8 euros a piece for 500 uF 900 V.
Not DC Link (apologies 😉) but I have also been impressed by Kemet's PEG124 series axial electrolytics (high temp, long life ....)
As an alternative, would adding a small cap (e.g. less than 1uf) be a good middle ground between choke input and traditional cap input? I.e. clclc with a small c in the first cap position?