1) No, that would actually make the filtering worse.
2) Leave empty. You won't need them. (well, maybe perhaps possibly if you have a horrible and nasty transformer, the input snubber, but the output snubber? Nope)
3) Where are you going to order parts from? I'll happily look and give a specific recommendation.
That said, the most important criteria are that they fit...
Electrolytic capacitor
snap-in
10mm lead spacing 2-pin (normal on 10mm, but make sure)
Max. 35mm diameter
No real limit to height
At least 15,000uF
At least 25V rated
More voltage rating will give longer life.
Also, generally speaking, a bigger can for a given capacitance will have more ripple rating, and, more life due to running it at a lower than maximum load.
105C rated caps will also give longer life since you'll be running them under that rating.
If I was to order tonight from Mouser, I'd get these -
SLP223M035H9P3 Cornell Dubilier - CDE | Mouser
2) Leave empty. You won't need them. (well, maybe perhaps possibly if you have a horrible and nasty transformer, the input snubber, but the output snubber? Nope)
3) Where are you going to order parts from? I'll happily look and give a specific recommendation.
That said, the most important criteria are that they fit...
Electrolytic capacitor
snap-in
10mm lead spacing 2-pin (normal on 10mm, but make sure)
Max. 35mm diameter
No real limit to height
At least 15,000uF
At least 25V rated
More voltage rating will give longer life.
Also, generally speaking, a bigger can for a given capacitance will have more ripple rating, and, more life due to running it at a lower than maximum load.
105C rated caps will also give longer life since you'll be running them under that rating.
If I was to order tonight from Mouser, I'd get these -
SLP223M035H9P3 Cornell Dubilier - CDE | Mouser
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IIRC the ripple current rating is very important. Unfortunately I cant find the post, maybe someone knows off the top of their head what the minimum requirement is.
Thanks 6L6. Much appreciated. I can order through either Mouser or Digikey with the latter being slightly easier (only because the BOM has DK product codes) but I'm happy to go with either.
Google PSUD2, download it, and play around with it. It's got a terrible user-interface, but is still wonderfully useful.
It will tell you, among other things, the voltage across your capacitors, the ripple current they're getting hit with, and the residual ripple your amplifier will see.
You can then experiment with different R values and different C values.
If you get stuck trying to figure it out, just post here. A lot of us use it.
Cheers,
Jeff.
It will tell you, among other things, the voltage across your capacitors, the ripple current they're getting hit with, and the residual ripple your amplifier will see.
You can then experiment with different R values and different C values.
If you get stuck trying to figure it out, just post here. A lot of us use it.
Cheers,
Jeff.
It is worth reading all the old articles that N.Pass has published.
They give lots of very useful background, much of which will help you to decide where normal parts can be fitted and where selected/special parts are needed. And how to select them.
They give lots of very useful background, much of which will help you to decide where normal parts can be fitted and where selected/special parts are needed. And how to select them.
Hi all, just wondering if Cornell Dubilier capacitors are o.k.to use in the power supply build. Digikey part number 338-1579-ND or 338-1614-ND. Was hoping to use some Nichicon, but the snap in of suitable size don't appear to be available for some time, same with the Panasonic that seem to be used in a lot of builds. Some are no longer available. Digikey cross reference some Rubycons or the Cornell Dubilier. The main reason for asking after 6L6 mouser link on 30th Jan is the ones I linked are available locally. I must have missed them off my parts order from Mouser when ordering parts for amp and supply. Thanks and apologies for newbie question.
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Hello again. All my parts have been delivered. I bought R1 to R8 per the BOM. Do I install them all? I think I saw a photo somewhere here recently with less installed.. It's going to be a supply for an Aleph J.
vlv81 - Use whatever caps you can get that are the proper size, value and voltage rating. There's honestly not much difference between capacitors.
Roo2 - Use (4) 0.47ohm 3W resistors per rail. Leave the snubbers empty. Make the bleeder anything between 2.2K and 10K 3W, and the LED resistors 10K or so.
Roo2 - Use (4) 0.47ohm 3W resistors per rail. Leave the snubbers empty. Make the bleeder anything between 2.2K and 10K 3W, and the LED resistors 10K or so.
Can i ask why the snubber is left out? Is this simply because this supply is known to be stable in this configuration/usage?
I see, so this is mostly required for switching noise in class D amps (this is how far my reading has gotten me), or is there a use for them in other topologies?
Newbie questions from a newbie, i appreciate the patience 🙂
Newbie questions from a newbie, i appreciate the patience 🙂
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Output snubbers are a combination of R and C in series/parallel with the filter capacitor. It act to keep the impedance of the smoothing network more constant under varying load from the output stage.
It's easier and better to just make the PSU bigger. The "big and dumb" approach is a very, very good way to make a quiet, smooth and stable PSU - there are lots of engineering band-aids to avoid using big and expensive capacitors.
In DIY, having a capacitor bank that costs $50 is not a big concern to a builder making one or two amps. But at retail you have to add a multiplier of at least 4X (some would say it's closer to 8X now...) to the retail price, making that capacitor bank add at least $200 to the retail price.
It's easier and better to just make the PSU bigger. The "big and dumb" approach is a very, very good way to make a quiet, smooth and stable PSU - there are lots of engineering band-aids to avoid using big and expensive capacitors.
In DIY, having a capacitor bank that costs $50 is not a big concern to a builder making one or two amps. But at retail you have to add a multiplier of at least 4X (some would say it's closer to 8X now...) to the retail price, making that capacitor bank add at least $200 to the retail price.
Thanks for elaborating, that makes perfect sense. I guess another plus for big cap banks is they look cool 🙂
It will bleed the caps slower. I used 22k as well for my F6 and it works fine, still takes less than 30s iirc.
Twenty years ago we placed plastic film caps in parallel with the electrolytic PS filter caps to improve high frequency performance I think, do we no longer do this?
When they are new.. however PS self inductance compensation networks are about maintaining predictable high frequency impedance/stability for the long term, especially so as aging effects come into play.
Considering high performance DIY amps like Pass and Hiraga etc can have very wide power bandwidths, I prefer to hedge my bets so to speak with well behaved PSupplys.