Aleph 1000

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[FONT=Verdana, Arial, Helvetica, sans-serif]In-Rush Currents[/FONT]
[FONT=Verdana, Arial, Helvetica, sans-serif]A consequence of the superior magnetic properties of a toroidal transformer is that the transformer "remembers" what polarity the primary voltage had immediately before the power was last shut off. Whenever the voltage has the same polarity when the transformer next is turned on, the core will saturate for part of a half-cycle, and a high in-rush current will flow in the primary of the transformer. This in-rush current is larger than the in-rush current in a conventional transformer, but it is of very short duration, so it will not affect slow-blow fuses or magnetic overload protectors with thermal delay characteristic. (Some delayed magnetic overload protectors act instantly if the current exceeds a certain value. These cannot be used with large toroidal transformers unless a current limiting resistor is used as described below.) [/FONT][FONT=Verdana, Arial, Helvetica, sans-serif]For very large transformers (1,500VA and up),it is common to use a small current-limiting primary resistor to reduce the magnitude of the in-rush current, and a delayed by-pass relay to short out the resistor after 30-200 milli-seconds. This method eliminates external voltage dips caused by the in-rush current, but slow-blow fuses or delayed magnetic overload protectors must still be used, as is the case for all types of transformers.[/FONT]​



5,000 va 10.4"x4.7" 56 lbs

Sounds like the solution to inrush is to make it not remember, or turn it on and off at the right time everytime!
 
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i hope you'r not serious about this.
that will demand a X'ed cuircut. with +/-70V rails and 16A bias pr half.
and a dissipation of about 4500W pr ch. with 120V mains, you are looking at almost 40A Draw pr ch. good luck:)

That number is close to what I was told. Thanks. Getting rid of the heat should not be a big issue, but power might be, love to learn.
 
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Caps are the BIG issue. I rember that it was the single most expensive part of my aleph. 100v prices are not good at all. I know in one of mazda's new cars they have a supercapacitor, it can runn all the accesories for up to a minute, andyone wreck one lately? Must be the prelude to the still impossible to get flux capacitor.
 
If you are building a 1000 watt Aleph, you will need more than 100V caps.

Rails at +/-100 V will give you about 600 rms watts tops (about 1200 watts
peak). You are looking at 150, better yet, 200V

:cool:

It seems the price really skyrockets as that v number goes up. And I would assume you need even more of them to boot. My aleph3 has 4 68,000uf 25v caps. Running at around +/- 24v now. Maybe I should have put a safety margin in?
 
I'm sure you're fine.

But you are getting a quick picture of how much cost is involved with a
1000 watt Aleph.

It could be worse, the SIT-1 has about 6% efficiency or so. Imagine having
to source and dissipate 16 KW.

per channel.

:cool:

It wouldn't be a problem to get rid of the heat, it wouldnt be real expensive. The amps and power supplies don't need to be fancy, just work. I think the 5kw transormers will work though (each mono). Need to do more math, im learning and getting my head back into it. I can do good work, and this can be done. I just wish there would be a way to use less outputs, just bigger ones as it would make it easier. Thank you
 
It seems the price really skyrockets as that v number goes up. And I would assume you need even more of them to boot. My aleph3 has 4 68,000uf 25v caps. Running at around +/- 24v now. Maybe I should have put a safety margin in?

150 sounds like a good round number, yikes, I need the cap fairy but im not going to give up on this, these really are "simple" construction amplifers, I looked inside a sony, what a mess! :headbash:
 
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2500VA??? you need 10.000VA pr ch.
and around 1.500.000uF cap bank pr ch. and a softstart AND a slowcharge that can handle this. and you will need some serious mains to handle this. 9000W at idle.
just forget it.

Im only worried about caps now. 1.5 farads? Really? It's the only thing in the way, but there must be one... Seriously, is there some caluculation, Id ask my stepdad but he still won't talk to me, it's a shame. In time maybe, oh can he work a caluculator and make boards! He just thinks his .007% amp is superior, he needs to do some reading too. Maybe he has a box of caps? wifey...
 
I just wish there would be a way to use less outputs, just bigger ones as it would make it easier. Thank you

Use mosfet in isotop case.
 

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you are looking at around $2-3000 for transformers. $2-4000 for caps. $1000 for output devices. and then there is heatsinking, metalwork and all other Components.
i quess you end up around $10-12.000 pr pair. or maybe more.

Sometimes a project like this you start on early, make a list, check it twice. I think the 5kva transformers will suit this application, I don't think they are that much, i will double check it today as I have a more relaxed schedule. I slept good and got caught up on things yesterday. As far as the caps, I have no easy answer for that one, It is what made me sleep after scouring the net. It's probably going to save me money by taking my time, and getting the deals. Time is all I have right now.
Thank you
 
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Out of curiosity, how would you setup the front end of an Aleph or an AX to drive this many outputs?

n3szd, what speakers will this amp be driving?

I think you'd be better off with a 200W aleph, with a ridiculous bias...say 10amps. Pretty extreme and still a challenge no doubt, but much less of one that what you're proposing.

-john
 
The whole point of the post was to create what didnt exist for those who need it. There are decent speakers out there that require silly numbers, I thought they deserved some real quality for once.

Im no engineer, I admit that. Can I built, no doubt. My trouble is putting it on paper, and money at this point, maybe the 1000 will have to wait a few years, maybe now it has to be the 500. I think given what you guys are saying that this would still be tough but would seem more paractical.

The beauty of the single ended class a, is that it is amplification that is simple, comparitively. There arent a million devices to make it sound worse, it's tubes done with electronic replacements.

The metal work for me is no issue, i get my stuff for free. The heat sinks can be done cheap as well. It's down to paper, transformers, capacitors. I will want to limit this challenge to a 5kva transformer per side as it's just on the borderline of nuts. How many watts of aleph poer can I get with that? I like those isotop packages, don't know if there practical in this application, 200v 110a 500w diss. But theres more than those numbers that would be critical to determine if they would work, it would make life a little more easy. so 10-15kva aint happining, I just never thought you needed that much, I will now work with 5, what can I get out of it?

I really appriaciate all of your input a lot. :p
 
Out of curiosity, how would you setup the front end of an Aleph or an AX to drive this many outputs?

n3szd, what speakers will this amp be driving?

I think you'd be better off with a 200W aleph, with a ridiculous bias...say 10amps. Pretty extreme and still a challenge no doubt, but much less of one that what you're proposing.

-john

I like the idea, but if I can do 500? Somewhere somehow something new will come, and help and ideas like this forum are very therapudic.5000va torroids, what can they make?
Thank you!
 
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