Aleph 5 single PS or dual?

[Leeuwarden]

Some time ago I completed my Aleph 5 using Kristijans boards. It worked as advertised from the first time I powered it up. This made me very happy because I know nothing about electronics. Because this was the best amp I ever had I decided to make my speakers active and build me another Aleph 5! (Silly me...) This time I was able to buy Brian GT boards from a friend of mine. I'm still working on this Aleph 5.

So far no problem.

In the mean time I have also build an UcD-400. Also a very good amp. One Aleph 5 is going to be used for the tweeter and the other Aleph 5 for the mid-speaker, the UcD is for the bass.

So here's the problem. My original Aleph 5's are in (too) big cabinets. Building another set of these cabinets is too much for my livingroom. (my speakers wouldn't fit in anymore...). So I'm trying to make the smallest (??) possible cabinets for a stereo Aleph 5. It would help save space if I use only one transformer per two channels. I use a 625 VA (2x30V) transformer for a mono amp at this moment with about 200.000 uF electrolytics. I could beef up in uF because I have some more electrolytics lying around. So this would result in a two channel amp with 625 VA and a lot of uF for my left sperker and the same for my right speaker.

My question: Is 625 VA enough for two Aleph 5's? Would I hear the difference between a dual mono or a single power supply.

Remember I know + from - and can recognise a resistor but that is as far as my elecronics knowledge goes....

Thanks!

Jan

[jh6you]

According to Aleph5 service manual, each channel draws about 150W, i.e. two channels 300W. I think that 625VA is the OK size if its manufacturer has made it honestly.

As a diy audio freak, I prefer the single power supply to the dual mono.

Good luck.

Regards
jH

[Leeuwarden]

Originally posted by jh6you


As a diy audio freak, I prefer the single power supply to the dual mono.

Good luck.

Regards
jH

Thanks JH.
Why do you prefer single PS over the dual? I was always told a dual PS is always better... (and takes more space :-( )

[Duck-Twacy]

Maybe (for peace of mind) sell the 625 VA and buy a pair of 800 VA?

You will lose a bit of money though. on the onther hand, being only used for mid and high, how much reserve will you need? The main benefit (I think) of bigger toroids will probably be that they will stay cooler...

[Duck-Twacy]

Originally posted by Leeuwarden
...
Remember I know + from - and can recognise a resistor but that is as far as my elecronics knowledge goes....

Thanks!

Jan

But he has built himself 3 different amps, a CD player, 2 different speakers (at least), a diy electrostat and probably a crossover...

[jh6you]

First, physically convenient.

Second, if I use 310VA-310VA dual mono, I could supply each channel maximum 300VA. But, if I use 620VA single supply, I can have better flexibility in power supply. For example, in case one channel needs 400VA (peak) and another 220VA, or vise versa, during playing music, the single supply could cover the case. (This might be not applicable in pure class A operation, though.)

Third, some commercial people say that the dual mono supply provides better stereo sound separation between left and right channel than the single supply. But, I do not believe it.

Regards
jH

[jeapel]

to duck-twacy "a pair of 800 VA?"

my futur project will be aleph5
and i would like to get more explications
on your experience and problem with aleph toroid
to do a good choice because to my newbie side
2 X 800va seem very big but maybe
there are advantages to oversize toroid

-cooler sure

-more stable voltage ????

thanks

[Stabist]

Leeuwarden - you can easily use 625VA tranie for both channels!

Btw - around a year ago frend of mine done some measurments of his A5
I gues you know the equation for power goes S=P+Q (in "complex" system) (P = working power and the unit is [W], Q is reactive pover - unit is [Var], S is "total power" - vector summ - and in [VA])
- it draws around 300W of "P" and around 500VA of "S" for stereo - so with 625VA (that's S) the trannie is big enough. Still oversized as a matter of fact

[Duck-Twacy]

Originally posted by jeapel
to duck-twacy "a pair of 800 VA?"

my futur project will be aleph5
and i would like to get more explications
on your experience and problem with aleph toroid
to do a good choice because to my newbie side
2 X 800va seem very big but maybe
there are advantages to oversize toroid

-cooler sure

-more stable voltage ????

thanks

800VA for a two Aleph5 channels (you could see stereo Aleph, but he is planning to use 2 Alephs for each channel, so naming it a stereo Aleph is not quite right) is not that much oversize (although 625 VA is within required specs). At the moment Leeuwarden is using 625 VA for 1 Aleph channel.

So also channel separation is not an issue here. Each channel has its own PS.

[jeapel]

sorry duck it s my misunderstanding