Power output into 4 ohms

[habsrock93]

I'm confused , which sadly happens more then I'd like to admit. I'v searched though many threads and through google, but still the answer eludes me. If both the Aleph 3 and Aleph J operate in single ended class-a mode, why does one double it's power into 4 ohms and the other halve it's power.

Aleph 3 60w into 4 ohms

Aleph J 13w into 4 ohms

Thanks for any input

Dave

 

[tinitus]

Aleph 3 60w into 4 ohms

maybe only in AB, and not classA

 

[Melon Head]

Its all in the Aleph current source setup.

You can adjust it if you want.

 

[habsrock93]

Ok, great. Thanks for pointing me in the right direction. I found the article "Zen Variations - Part 2, The Penultimate Zen’s Current Source" It's a little late for a read now, but the title sounds promising

 

[Bill Fuss]

The different sections of the Aleph amps are quite interchangable if you understand the different functions being used. I've just finished up a pair of monoblocks optimized for 4 ohms using the front end of the J and the output section quite like the 30 except with 3.6A bias and 55% AC current gain. It's quite easily done but does change the original design parameters so I just call them Alephs. They have bags of current capacity for difficult loads.

 

[Nelson Pass]

You can make an Aleph deliver beyond the Class A region,
but it's not pretty.

Wensan built a follower version that does the job - maybe he
will comment here for you.

 

[wensan]

Here are the schematic and distortion curves of my SRPP power buffer what I built.
The bias current is about 0.75A.
The AC gain is about 85% in order to let it work in Class AB mode.
If the AC gain is 50%, it cannot work in Calss AB mode.

 

[Melon Head]

Thanks Wensan

The other option worth considering is connecting up Aleph J with BA 2 Output stage.