Experimental powersupply for Aleph4

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Hi,
I'm currently building an Aleph 4 with many expectations.
Does it really sound so different compared to other amps?
(What a great forum!)
I have in stock 2 times 500VA 2x35Vsec transformers and want it to use it in this schematic (see picture)
Is this OK?
The heatsinks that i'm planning to use has got a size of 32cmx30cm per each channel wich comes around 960 square centimeters. Mcfinnis has got 1060. So I think I come pretty close!:cool:
Thanks in advance
Remco
 

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Thanks Mr Pass!
So should go for 1 peace of 1KVA!
(then I'm having trouble with space)
I'll figure something out...:mad:
Any other solutions?
I've got spare space of 6.6cm by 30cm just enough for 2X500VA.
The fahrads is hopefully enough!
Give me your opinions! I love it!
Thanks everyone!
Remco
 
Hi Remco,

you could always use PSUdesigner for these kind of questions:D
It´ll give you very good figures for all the currents/voltages in your supply.
With these caps and chokes you should get around 10-20mV ripple @ 3A.

(don´t have the link at the moment though:rolleyes: )

william
 
blank527 said:
Thanks Mr Pass!
So should go for 1 peace of 1KVA!
(then I'm having trouble with space)
I'll figure something out...:mad:
Any other solutions?
I've got spare space of 6.6cm by 30cm just enough for 2X500VA.
The fahrads is hopefully enough!
Give me your opinions! I love it!
Thanks everyone!
Remco

You should not load a transformers for more than 60% . So 1000VA with a contigious load of about 500W is close to there limit. My 1000VA running 250W is till getting hand warm and produces a little hum... I hate to think when you contigious load of twice 250w... When you load them beyond 60% the voltage will drop dramaticly!

Mine 1000VA 40-0-40 with 88000uf with a 250W load gives about +49.2V ... I hate to think what happens when you load 2x500VA 35-0-35 with 500W ...

Edwin
 
blank527 said:
So the original Aleph 4 uses also 2X 1000VA transformers?
I thought it uses only 1 transformer according to other threads.
Can anyone post some inner pictures from the original Aleph 4?
Thank you,
Remco

For capacitor input linear power supplies with constant average load like this, minimum transformer rating is Power draw / 0.62 so for the Aleph 4 with constant draw of 500W, minimum transformer rating is about 810VA so 1kVA is enough but in practice we always like to over do things, personally, I would use separate transformers for each channel with 1.6kVA per channel but that is just my personal taste in excessiveness.
 
The transformers are seperatly from each-other, so 1 transformer feeds the nagative rail. And the other feeds the positive rail.
So on theory they do each 50 percent of the work. If you got a 60 herz wave, then on the positive side of the wave, is for one transformer and the other is idle. And when the wave comes in the negative side, the other transformer comes into action.
I hope I discribed it understandably:confused:
Thank you,
Remco
 
so your saying that if the thing ( toriodial ) gets hot and shorts out and sends the full 110Vac ( or 220 ) throught your caps and then to your aleph amp that just costed your mountians of money to build and catches fire and burn hour house down your just going to say oh well..

ID spend the extra cash and but the right toroidial..

but that is just me any one else here agree..

?
 
blank527 said:
The transformers are seperatly from each-other, so 1 transformer feeds the nagative rail. And the other feeds the positive rail.
So on theory they do each 50 percent of the work. If you got a 60 herz wave, then on the positive side of the wave, is for one transformer and the other is idle. And when the wave comes in the negative side, the other transformer comes into action.
I hope I discribed it understandably:confused:
Thank you,
Remco

Hi,

I think your biggest problem is, you will not get 48V ! With my 1000VA 40-0-40 I get with a 250W load about 49.4V !!! Which give a factor of 40 * 1.225. So with 35V you will get about 42.8V and I do not even count your chokes, and your lower VA rating!

Edwin
 
Well, that's not exactly what I was saying, but you're right!
I just find it terrible that i've got the transformers in stock!
Now i'll have to spend about 300 euro's for 2X1KVA transformers.
:mad: And since i've got every so part cheap (200 euro), i'll think figure something out, space is not the problem because I made an second floor in the amp wich can carry the toriods. You'll see it when the amp is finished and posted on Passdiy.
Thanks,
Remco
 
Edwin,
I think there is something majorly wrong about your findings. You either have a crappy transformer or you are doing something weird. Never mind the 250W resistor power rating, what is the actual resistor value in ohms?

Blank, in your design
the transformer maybe operating at their nominal power level but the duty cycle is only 50% so they should be just fine. If the transformers are identical why don't you parallel everything up in a more traditional design and be done with it?

so your saying that if the thing ( toriodial ) gets hot and shorts out and sends the full 110Vac ( or 220 ) throught your caps and then to your aleph amp that just costed your mountians of money to build and catches fire and burn hour house down your just going to say oh well..

A device known as the 'fuse' has been created to prevent such accidents from happening.
 
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