What's everybody using and liking for PSU caps of 500v and above?
- electrolytics, if so which ones?
- DC Link caps from Kemet, Epcos, Vishey etc?
- polypropylene in general including motor run caps?
- PIOs, if so which?
- other?
I don't see a thread on this and it would be good to have up-to-date information and preferences.
- electrolytics, if so which ones?
- DC Link caps from Kemet, Epcos, Vishey etc?
- polypropylene in general including motor run caps?
- PIOs, if so which?
- other?
I don't see a thread on this and it would be good to have up-to-date information and preferences.
For electrolytics over 450v I use two in series with balancing resistors. It’s a lot cheaper and gives you a lot over overhead so you’re not right at the limit. For power supply polypropylene I use Solen caps because they are 630v and not too big to fit. The price is right too. Motor run caps are huge and it’s harder to find ones that are rated over 500 in the US. You can always bypass with a fancy cap if you are inclined.
I'm using electrolytics rated 500v, now available from the major manufacturers, at least in the U.S. I haven't made the jump to film caps for power supply, since I've gone to big cap banks (e.g. 400 uF for push-pull EL34 mono) and an apples-to-apples comparison in film caps would be $$$ and lots of space!
I'm using a 630V solen film for the first smaller cap, where the voltage is highest and then a larger 500V electrolytic after the choke, after things have calmed down some. If I was using voltage higher than this could handle, I'd go with stacked caps with resistors.
I've been playing around with 3 or 4 power supplies which deliver 350v DC off around 350v AC. Small cap on input, 5U4 rectifier, hybrid Graetz bridge. First of all, I eliminated the usual motor runs - tubby and slow. I currently have a small metallised polypropylene cap on the input, then a good size choke.
After that I'm flipping between a Kemet ALC10 electrolytic 550v and Kemet C4AQ or C4AE DC links which are 900v or round about that. I suspect the ALC10s have a little more micro detail, while the C4AQ are smoother.
Last cap, after a dropper resistor, is another C4AQ of 12uF. I have some Russian PIOs, KBG-MN, I could use instead as the last cap. Even the 6uF 600v is huge, and being square I haven't thought out how to mount it yet. Everyone speaks highly of these. But how do you mount a large square capacitor? Talking 11cm high and 6cm square.
After that I'm flipping between a Kemet ALC10 electrolytic 550v and Kemet C4AQ or C4AE DC links which are 900v or round about that. I suspect the ALC10s have a little more micro detail, while the C4AQ are smoother.
Last cap, after a dropper resistor, is another C4AQ of 12uF. I have some Russian PIOs, KBG-MN, I could use instead as the last cap. Even the 6uF 600v is huge, and being square I haven't thought out how to mount it yet. Everyone speaks highly of these. But how do you mount a large square capacitor? Talking 11cm high and 6cm square.
If you look at my photo above, the Mundorf M-Tubecaps are square (to the left of the electrolytics). I fabricated a bracket out of a steel tie strap and bolted them to the underside of the chassis. Kaptan film underneath and around the caps for a little extra insulation.
I'm breadboarding something at 700V now. I used series electros for the C1 reservoir. Followed by an LC stage which is also series electros. Followed by two RC stages split (left/right) that final split L/R stage uses 80uf 900V DC link Kemet's (Kemet is cheapest it seems). I figure most of the "music signal" that passes through the power supply will pass through the last capacitor right? Why would it crawl up the supply any further? So I figured it cant hurt to use a film cap last that can handle the full voltage. I often see this cap bypassed with a small film cap when its an electro, dont know if that does much. The series electros have balancing resistors of course.
https://www.mouser.com/ProductDetail/KEMET/C4AQOEW5800M3BJ?qs=81r%2BiQLm7BTCIar2VL/0vg==
https://www.mouser.com/ProductDetail/KEMET/C4AQOEW5800M3BJ?qs=81r%2BiQLm7BTCIar2VL/0vg==
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I use these - 10000H @ 105°C and AEC-Q200 rated...
Ymin | Ymin LKMJ3552H101MF | Aluminum Electrolytic Capacitors - Leaded - LCSC.COM
Ymin | Ymin LKMJ3552H101MF | Aluminum Electrolytic Capacitors - Leaded - LCSC.COM
Don't forget that motor run caps are rated in Vrms so a 480vac cap should be good for over 670v peak or DC + ripple.
John
May I ask you how you managed the insulation between chassis and top capacitors, when the housing of the cap is >1kV compared to the grounded chassis? Is the film wrapped around them enough?
Thanks
> Kemet ALC10 electrolytic 550v
hey Andy - those 550V ALC and ALS types are much better parts than other electrolytics, (I tested the similar ALS60). They degrade much slower than standard electrolytics (pH neutral electrolyte) and this shows up in the lifetime specs. The dissipation factors are better too, and I think you can hear the difference. No-name consumer parts degrade quickly, especially if they get a bit warm.
I suspect that ALS series to bring the ripple down, and a RC or LC with a DC-Link for decoupling the valve stage would make a good combination.
hey Andy - those 550V ALC and ALS types are much better parts than other electrolytics, (I tested the similar ALS60). They degrade much slower than standard electrolytics (pH neutral electrolyte) and this shows up in the lifetime specs. The dissipation factors are better too, and I think you can hear the difference. No-name consumer parts degrade quickly, especially if they get a bit warm.
I suspect that ALS series to bring the ripple down, and a RC or LC with a DC-Link for decoupling the valve stage would make a good combination.
Yes indeed - that's exactly what I've been trying. I made a note of your previous recommendation. It's a toss-up between the ALC/S and a Kemet DC Link for the main cap.
On your recommendation I also passed on all my motor run caps to the poor of the parish. Let's just say I overrated them.....
In case you were sacred of using Ymin, I also recommend TDK/EPCOS. These are 47uF/600V
And the Kemet parts Rod mentioned are great, too.
https://canada.newark.com/epcos/b43541b8476m000/cap-47-f-600v-alu-elec-snap-in/dp/16AC3106
And the Kemet parts Rod mentioned are great, too.
https://canada.newark.com/epcos/b43541b8476m000/cap-47-f-600v-alu-elec-snap-in/dp/16AC3106
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Those 550 volt Kemet ones are the highest V electrolytic I’ve tried - and they’ve been fine. If it’s much more than 500 and a high value required, I still put two 400’s or 450’s in series - Panasonic or Nichicon usually. For caps 40 uF and under, I’ll go to MKP motor run caps even if high voltage isn’t required - but almost always buy those surplus at pennies on the dollar. I keep a pretty good size stash mostly for speaker crossovers, but they can find their way into a tube amp build when it’s the right part to use.
Where do you get those Electronicon caps? They're made in Germany but I don't see them from most of the usual sources?
Tell us more - what's the construction, how do they compare with Kemet, Epcos and the others?
Tell us more - what's the construction, how do they compare with Kemet, Epcos and the others?