Aleph 2 capacitor ?

[jeclk]

try to build aleph 2,
but I would like to know what I should take as Capacitor of power example:22000uf/40v or 22000uf/63V
it's a question

And where to buy them cheap (little price)
can you give me a name some of the shop or somebody

help please

[wuffwaff]

Hi,


you´ll have to buy caps with a voltage rating a bit higher than the power supply voltage. How much higher has been discussed here before but anything about 10% above the supply voltage will do. So in the case of an Aleph2 (45V) you must look for 50V or higher.

Cheap capacitors are quite easy to obtain in surplus shops. The only problem is getting enough of the same sort.

william

[Bakmeel]

How much improvement would you get with improving the total capacity? Say, I'd double it and add a choke... Would it improve the sound much?

Bouke

[jeclk]

i don't undestand
Bouke
sorry

[Bakmeel]

Well, I guess it's just an obsession of mine, but I am a bit fond of big capacitor banks. I am in the assumption that it is good for the amp, and thus for the sound.

But I'm curious to know if it's really true! I recently heard that you can also have too much capacity.

And then again, Such elko's are expensive.. So I am wondering wether it is or isn't a waste of money to add capacity to the aleph 2 design...

Bouke

[halojoy]

You can not have too much capacitance.
That is: very much will not make things worse.

But at a certain value, the addition of more cap
will make so little difference,
that you can say there is no improvement.

So you can definitively have UNNESSESARY capacitance.
That is a waste of money.
And in that sense it can be described as "too much".

[Bakmeel]

Well, this is what I heard about having too much capacity.. It's a bit contradictionary (is that a word? ), but here goes:

If you have too much capacity, you will have less ripple.. that is a goal. But in the mean while, the diodes in the rectifier bridge will only conduct for a very short period of time. That is, only when the voltage on the AC side is higher than the DC side.
I that time, a (large) current flows to refill the capacitors.
It's those peak current that makes the power supply restless and, it adds HF noise on your power rails.

But the solution is a bit stupid in my ears. You should decrease the capacity to have more ripple, so the loading peaks will be "longer" and thus add less HF noise to your power rails??

Confusing huh?

Bouke

[wuffwaff]

Hi Bouke,

not confusing but difficult to know wich value to choose. That´s why I would go for a pi-filter setup with rel. small first capacitors (say 20-40mF for an Aleph 2) and then a large second bank (60-80mF). In between something like 2mH would do nicely.

This setup avoids large inrush currents AND keeps the ripple really low.

william

[jeclk]

hello women and men,
escuse my english
(hahahahahah)

I think sincerely that a big food of qualite,improve the music on all the busy band(strip). It is necessary filter the current of condensers with MKC 2,2 uf / 250v and to put a serie of 4700uf for the fast modulation for passing pointed and grave

[Duck-Twacy]

I'm not an electronics expert, but I heard (from somewhone who is) that you can have too much elco capacity in your powersupply.

It is suposed to make the amplifier "slow" (because the impedance increases with frequency, or someting). Is this true?

Bouke, hear is the link, (its in Dutch)