I hope this is not one of those “dumb questions” but it may be. Is 100 watts class A the same as 100 watts AB. When it comes down to chassis, the specs claim an AB chassis is good for 100-130wpc. Can the same chassis be used for a 100wpc class A Aleph2 or would the sinks need to be larger?
Never a dumb question. I would much rather have more to learn than to know it all. Class A/B amps are amps that have only a small amount of class A bias. So say for a 100 watt amp, maybe 5-20 watts may be class A where it goes into class B, hence Class A/B. when a Class A/B amp leaves it's class A envelope, the bias increases.
One thing to keep in mind is the efficiency of speakers. You generally don't need too many watts. Just really good ones. 🙂
Having less class A bias, they produce less heat.
This may be a good read for you:
https://www.passlabs.com/technical_article/leaving-class-a/
One thing to keep in mind is the efficiency of speakers. You generally don't need too many watts. Just really good ones. 🙂
Having less class A bias, they produce less heat.
This may be a good read for you:
https://www.passlabs.com/technical_article/leaving-class-a/
If like me you do much of your listening in the 1 watt window then the peak current into 8 Ohms is .5 amps which would call for about .25 amp bias. Not really a high figure at all.
25w of real classA burn on heasink 70w to 100w x side, look here https://diyaudiostore.com/collections/deluxe
https://www.firstwatt.com/prod.html
Hi
If the specs you obtain claim an AB chassis is good for 100-130wpc. The same chassis can’t be used for a real 100wpc class A.
A Class A power amp rated 100W will need huge heatsinks.
Eric
For Aleph 2 monos compare the price including shipping:
2x Modushop / DIYAudio 5U Deluxe Chassis (tried and testd) vs. 2 of the ebay specials.
Repeat: factor in shipping!
Then... Factor in pre-drilled / tapped heatsinks & pre-machined rear panel on the DIYAudio chassis.
2x Modushop / DIYAudio 5U Deluxe Chassis (tried and testd) vs. 2 of the ebay specials.
Repeat: factor in shipping!
Then... Factor in pre-drilled / tapped heatsinks & pre-machined rear panel on the DIYAudio chassis.
Oh for sure, the DIY Store is the best economical decision. I’d just like to know if there are other options that’ll work for this particular build.
No. It all depends on idle Iq. Question is then, how much Iq you need. That is a completely different question than your first. 100 watts class A is not the same as 100 watts class A/B wrt dissipation. Unless you run that A/B circuit full throttle all the time.
Class A/B circuits are routinely used on chassises with way too small heatisnks. They may handle peaks well, but not long term use into tough loads. Example: Hegel H160, Krell KAV300iL. They all sound sublime. Until they get warm, at which time heat makes them work way putta spec.
So, 100-130wpc a/b, look at size: you’ll soon see if they can handle A.
How much Iq you need to keep you happy, is the question. If that figure keeps you in the happy range, any chassis will do. But your amp may not sound like intended with lower Iq. Solution: Modushop.
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So you're thinking about an Aleph 2? I didn't see it mentioned but have you seen this:
https://www.diyaudio.com/community/...s-builders-thread.382316/page-34#post-7224638
There is a pretty insigntfull document on the Aleph 2 that would be worth a look.
One consideration with two of the DIY chassis is you may want to come up with a circuit to get the gauge to show the bias. The nice thing about going with UMS style boards is that you can repurpose the heatsinks for other UMS projects. There is an etsy store where the boards and kits are sold.
https://www.diyaudio.com/community/...s-builders-thread.382316/page-34#post-7224638
There is a pretty insigntfull document on the Aleph 2 that would be worth a look.
One consideration with two of the DIY chassis is you may want to come up with a circuit to get the gauge to show the bias. The nice thing about going with UMS style boards is that you can repurpose the heatsinks for other UMS projects. There is an etsy store where the boards and kits are sold.