Aleph J Schematic

Thanks for the reply.
I understand the need for more bias, using more output fets would allow me to spread the dissapation if I was to increase the bias to 3.5 or 4 Amps. I was more concerned with bandwidth limitations and such changing the sound texture of the circuit. What are your thoughts on this.

Bill
 
What sinks are recommended for Aleph J?
Okay not which ones exactly, but how much heat are we dissipating and whats the thermal resistance we are shooting for? The Pass manual talks about how much power the amp uses and from that we can subtract the power to the speakers and assume the heat, but still the thermal resistance is in question. Little help please?
Uriah
 
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udailey said:
What sinks are recommended for Aleph J?
Okay not which ones exactly, but how much heat are we dissipating and whats the thermal resistance we are shooting for? The Pass manual talks about how much power the amp uses and from that we can subtract the power to the speakers and assume the heat, but still the thermal resistance is in question. Little help please?
Uriah


100W/ch diss.

say that you're good if you use 'sinks with 0,25K/W ; one per channel
 
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udailey said:
The F5 need ~.3C/W per channel since each mosfet needs .6C/W.
So, pretty much I could get away with using the same sinks with an F5 as with an AlephJ.
Is that about right?
ZM I assume you mean C/W when you say K/W.
Thanks
Uriah


nope ;

there is slight :clown: difference between ~60W/ch dissipation of F5 and 100W/ch dissipation of Aleph J

so - 'sinks adequate for F5 are eenyweeny for Aleph J

K and C are same drek , they just have 0 on different place :rofl:
 
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udailey said:
Okay okay, crazy Serb is trying to eat my wallet!
One more please ZM. Are we shooting for 20C over ambient temperature rise of the heatsink with J as in F5?
I am really not trying to make the J an F5 just trying to get a chassis/sink combo that I can use for both. Looks like 2 sinks per channel and use only one of them for F5.
Uriah

read more Papa's pdfs ; he's certainly better in 'xplaining things to our woodenheads than poor ZM :rofl:

25C over room temp is good enough , under condition that room have temp in which you're able to still breath in it ...... :clown:

test of "you can keep hand on 'sink for 5 secs" is one of most practical tests you can find on this site .....


salesmonster said:
Heatsinks is a topic I always get hung up on.

I'm getting ready to put an enclosure together for a J. What I'm considering vertical box with heatsinks from barrredboss on eBay. He has an 8.5 inch profile that can be cut to length.

Would a 12 inch section per channel mounted vertically be enough? Or should I go bigger?

Sorry for the ignorant question.

sorry - I can't see any handy link in your post ..... these days my eyes are already sore from too much googling ..... :rofl:
 
salesmonster said:
Heatsinks is a topic I always get hung up on.

I'm getting ready to put an enclosure together for a J. What I'm considering vertical box with heatsinks from barrredboss on eBay. He has an 8.5 inch profile that can be cut to length.

Would a 12 inch section per channel mounted vertically be enough? Or should I go bigger?

Sorry for the ignorant question.

That's not an ignorant question, many underestimate the HS requirements. I think Conrad heatsinks' website has some pretty good info on general guidelines.
I'm afraid a 12" length loses too much efficiency for one channel, but if you had them cut to 6" and made the chassis 17" deep you would be right at the minimum. Side by side they are quite a bit more efficient. Still, bigger would be better.

Best, Bill
 
Apex Jr. has some good deals on heat sinks. $20.00 each! I'm using them on my chassis.
 

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