Lucas,
nice amp you´ve build there! I like the way it is build using all three dimensions. Most amps are more 2 dimensional in there layout (not meaning that they sound flat or so......).
Do you think the plant will survice for a long time?
William
P.S. how much ripple do you have and how much voltage do you loose over the chokes?
nice amp you´ve build there! I like the way it is build using all three dimensions. Most amps are more 2 dimensional in there layout (not meaning that they sound flat or so......).
Do you think the plant will survice for a long time?
William
P.S. how much ripple do you have and how much voltage do you loose over the chokes?
" Since I too have 4 Ohm speakers I decided to use the resistorvalues of WuffWaff that he has posted in another thread. This leads to a higher bias. "
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Can some one lead me to this thread? Thanks..... Did a quick search but can't find it...
Mark
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Can some one lead me to this thread? Thanks..... Did a quick search but can't find it...
Mark
Mark A. Gulbrandsen said:
Hi Mark,
Wuffwaff made there the following comment:
"Since the last reports I changed the trimmers for R19 and R21 with resistors (49k and 390R) so now it runs at 2.4A bias and about 63% ac current gain (about 6.7A peak)."
These are values that I used too.
Regards,
Lucas.
wuffwaff said:
Hi William,
Thanks for your praise! This 3 dimensional way of building was neccesary to get all things into such a compact space.
Apparently it makes it difficult for some to understand how it is set up...
The plant would not survive, I guess, and nor would I when my wife would found out...
I don't know how to measure ripple. I don't have a scope.
I tried Duncan's PSU design tool and it showed a very low ripple.
The voltage drop over the chokes is less than 1 Volt.
I am also amazed to see a ratio between 30 VAC / 39 VDC of 1.3
Much higher than I had expected.
Kindest regards and good luck with you Aleph-X project!
Lucas.
Glad that the Seiferts are truthfull about their Cw value, because I have a pair the 300*200*83 mm KL271 for my Alpeh5s. Notice you also have some "spots" (beschadegingen) on them.
My youre amp is ugly btw Maybe I can make an even uglier one
PS The Seifert KL271 200 mm high costs 65 euro excl. taxes
My youre amp is ugly btw
Maybe I can make an even uglier one PS The Seifert KL271 200 mm high costs 65 euro excl. taxes
Duck-Twacy said:Glad that the Seiferts are truthfull about their Cw value, because I have a pair the 300*200*83 mm KL271 for my Alpeh5s. Notice you also have some "spots" (beschadegingen) on them.
My youre amp is ugly btw
PS The Seifert KL271 200 mm high costs 65 euro excl. taxes
Hi Duck,
Yes, there were already some spots on them when I received them.
I guess you can can fix these with the help of a permanent marker lik an Edding...
I will do that only after finishing the outside of the amp (concealing what you seem to be finding utterly ugly
).Regards,
Lucas
Here is a pic of my wannabe Aleph5 (still have to start building the mechanical part). It will be a dual mono case btw. Size will be 480 * 310 * 310 mm (on the outside ofcourse). It will have 2 layers. Below the elcos and conductors. Above it the trafo's (in the middle). PCBs at the sides against the Seiferts of course.
I will not be using a extra face plate or something, only L an T alu profiles.
Damn stains (fingerprints) on the aluminium.
An externally hosted image should be here but it was not working when we last tested it.
I will not be using a extra face plate or something, only L an T alu profiles.
Damn stains (fingerprints) on the aluminium.
Lucas_G said:
Hi Duck,
Yes, there were already some spots on them when I received them.
I guess you can can fix these with the help of a permanent marker lik an Edding...
I will do that only after finishing the outside of the amp (concealing what you seem to be finding utterly ugly
Regards,
Lucas
The spots are where the elektrodes for anodizing are connected. They are also on my SK157´s from Fischer.
william
Duck-Twacy said:Here is a pic of my wannabe Aleph5 (still have to start building the mechanical part). It will be a dual mono case btw. Size will be 480 * 310 * 310 mm (on the outside ofcourse). It will have 2 layers. Below the elcos and conductors. Above it the trafo's (in the middle). PCBs at the sides against the Seiferts of course.
An externally hosted image should be here but it was not working when we last tested it.
I will not be using a extra face plate or something, only L an T alu profiles.
Damn stains (fingerprints) on the aluminium.
Hi Duck,
That is going to be damn impressive!
So you use 2 pieces of 150 mm Seiferts on each side...
That should give you a C/W of about 0.06
This is a bit of overkill for an Aleph 5.
Even if you decide to rais the bias, as I did, your Aleph 5 won't dissipate more than 200 Watt. That means that your heatsink will reach a temp of appr. 200 x 0.06 = 12 degrees above roomtemperature. With 20 °C your amp will reach 32 °C.
This is bit low for getting up to its best sound, I think...
Why don't you use all that capacity to built an Aleph 2 instead.
You could even use your Kristijan Aleph 5 boards for that. You would only need to add an extra 6 Mosfets per channel and change some of the resistervalues...
Have you ever thought on building two monoblocks instead of one supersize stereo?
The weight of one stereo should easily exceed 50 kg. Hope you have got your back well insured for this
Good luck on building!
Lucas
Duck-Twacy said:
Hi Duck,
If it is all too confusing, than do ask!
I didn' kill the dogs...
I just sold them in order to finance my Passlabs hobby!
The Kaptons are a problem though. I bought them at the german shop: www.buerklin.com
They are cheap, but they don't deliver to private persons.
You can also buy them with www.thel.de but he charges a lot more of course.
However, if you can find them; they are the absolute best because through there extreme thinness they have the lowest C/W possible. Furthermore you don't need messing around with grease.
Greetings,
Lucas
Its even worse, they are 200 mm high. We didnt think that the C/W value actually was that low (as on the graph).Lucas_G said:
So you use 2 pieces of 150 mm Seiferts on each side...
That should give you a C/W of about 0.06
This is a bit of overkill for an Aleph 5.
Even if you decide to rais the bias, as I did, your Aleph 5 won't dissipate more than 200 Watt. That means that your heatsink will reach a temp of appr. 200 x 0.06 = 12 degrees above roomtemperature. With 20 °C your amp will reach 32 °C.
This is bit low for getting up to its best sound, I think...
Why don't you use all that capacity to built an Aleph 2 instead.
You could even use your Kristijan Aleph 5 boards for that. You would only need to add an extra 6 Mosfets per channel and change some of the resistervalues...
Have you ever thought on building two monoblocks instead of one supersize stereo?
The weight of one stereo should easily exceed 50 kg. Hope you have got your back well insured for this
Good luck on building!
Lucas
Funny problem he
Btw I use the PCBs of the Aleph4.
For an Aleph2 of 4 I would need another trafo I think (37V in stead of 30V)..
It will have a pair of strong handles (25 mm massive tube and some M10 bolts)
Duck-Twacy said:
Its even worse, they are 200 mm high. We didnt think that the C/W value actually was that low (as on the graph).
Funny problem he
Btw I use the PCBs of the Aleph4.
For an Aleph2 of 4 I would need another trafo I think (37V in stead of 30V)..
It will have a pair of strong handles (25 mm massive tube and some M10 bolts)
Hi Duck,
The 30 Volt Tranny would be just fine. it would deliver some 40 VDC when joined by all your caps.
This is some 10% less voltage the the original Aleph 2 but that only means you will have a slightly lower peak powerrating.
Since you have such extroardinary cooling-capacity, you could also choose to built an Aleph 2 with an extra high biasing, easily driving all kinds of loudpeakers and with massive slam and super soundquality! Do consider this.
How much VA rating do your trannies have?
If they have 500 VA or more they would easily do.
Lucas
Duck-Twacy said:
That would certainly do for a high biassed Aleph 2.
Furthermore the Amplimo's are really high quality transformators.
You could choose to connect 2 mosfets instead of 1 per connection on the Aleph 5 board.
If you need the different values for the resistors and capacitors on the PCB, just ask.
Regards,
Lucas.
I use this PCB
Btw is it possible to make an Aleph with 8 mosfets (IRPF240) per channel??? I do happen to have 2 sets of 8 matched mosfets?
An externally hosted image should be here but it was not working when we last tested it.
Btw is it possible to make an Aleph with 8 mosfets (IRPF240) per channel??? I do happen to have 2 sets of 8 matched mosfets?
Hi Duck,
You probably could do with 8 instead of 12 mosfets per channel.
Especially if you keep the temp down, because of your oversized heatsinks, they would survive 1.5 times the dissipation.
But why don't you use 2 times 6 mosfets for one channel, and then buy another two times 6?
Your pcb is wonderful for an Aleph 2. Take a look on Kristijan's site and you will see quite the same for his Aleph 2 boards.
You will only need two driversboards (easy to use standard breadboards) or just make p2p connections like many here have done (attach mosfets on heatsink and then solder copperwire in three rails with little connections to the pins of the mosfets.
Lucas
You probably could do with 8 instead of 12 mosfets per channel.
Especially if you keep the temp down, because of your oversized heatsinks, they would survive 1.5 times the dissipation.
But why don't you use 2 times 6 mosfets for one channel, and then buy another two times 6?
Your pcb is wonderful for an Aleph 2. Take a look on Kristijan's site and you will see quite the same for his Aleph 2 boards.
You will only need two driversboards (easy to use standard breadboards) or just make p2p connections like many here have done (attach mosfets on heatsink and then solder copperwire in three rails with little connections to the pins of the mosfets.
Lucas
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