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Old 22nd September 2015, 09:11 PM   #1
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Default Questions about the aleph 5

Hello,

Sorry, I use a translator because my English is not at the top

Just a few years I realized the aleph p 1.7. I finally launches in achieving the aleph 5.

I currently have two ilp 500VA transformer but 2x35 Volt. My question is what is the impact on the final assembly? Knowing that Mr Nelson PASS (my god) recommends tension to 34V.
What should I monitor tensions in particular and what will be my Current? 1.8 or 2A or more

Thank you for your answers
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Old 22nd September 2015, 09:24 PM   #2
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Surely someone in the same situation as me and just update the values noted in this diagram

http://www.diyaudio.com/forums/attac...-algar_emi.pdf
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Old 22nd September 2015, 09:47 PM   #3
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Hi,

A 2 x 35V AC transformer is way too high for 34V DC rails.

rgds, sreten.
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Old 22nd September 2015, 10:02 PM   #4
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Hello sreten,

Christian in this publication used a 2x35v and seemed confident about the operation, but it did not indicate the measured voltages on its mounting
A few Aleph 5 questions...
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Old 22nd September 2015, 10:06 PM   #5
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Options.
1. Buy new transformers
2. Build a higher powered Aleph. Probably require monoblocks with big heatsinks.
3. You could consider burning off some voltage with a regulated supply.
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Old 23rd September 2015, 03:27 AM   #6
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Since you have two transformers, you could consider a more powerful
monoblock. Just give it more heat sinking and it will probably work fine.

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Old 23rd September 2015, 07:36 AM   #7
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Hello,

Thank you for your answers.
I currently own two large heatsinks 0.16 /W. Do you think that will be enough for a channel or does it necessarily make mono block?
I wanted to make one box combining both channels
By my calculations, for my 150w dissipated through heat sinks are just ready to 24 .
With 2x35v I think beyond this temperature.
- Do you think it's reasonable to mount the 6 irfp240 on one sink?
- The bias should always be between 1.8 and 2A or stronger or weaker?

Thank you
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Old 23rd September 2015, 07:46 AM   #8
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Just to confirm. Your transformer has 35 V AC secondary windings?
If so, you will have well over 40V dc (approaching 50V).
With rails that high I wouldn't use anything less than 5A.
May as well make it 6 A.
That's a lot of heatsinking.
Edit:You don't have to do this, this assumes you want close to full power into 8Ohms. You could do less if you know you're never goint to need more than 3A, just a bit unconvetional for such high V rails.

If that is sounding too much it might be cheaper just to buy another set of transformers with 24V secondaries.
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Old 23rd September 2015, 08:42 AM   #9
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Yes I confirm that the secondary is 35V.

I also has 2 transformers 300VA 2x24V

- I realize is the aleph 5 with 300VA 2x24V
- Either I realize the apeph 2 with 500VA 2x35v but I need two new heat sinks
- I realize is the aleph 5 with 500VA 2x35 with a regulated power supply. Do you know a good regulated power supply?
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Old 23rd September 2015, 09:37 AM   #10
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If going with a regulated supply I'd use one of Nelsons simple shunt supplies. I think you will find one of those in one of the Zen articles.
It might be best to start with the 24V transformers and just go with a basic CRC supply. Start with a simpler lowered power version.
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