Aleph 30

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Aleph Front End Diagram

Here the Front End That I built. I hope there is no error in it.
 

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Aleph 30 Distorsion, Ok Now

After changing R4.75K to 3.3K as suggested from Mr. Pass (Thanks again Mr. Pass, you're the man)
my distorsion problem is present only near clipping, which is normal. According to the Aleph litterature, the active current source increase the Class-A efficiency. The clipping point is higher but distorsion increase near clipping. Exactly what I'm getting.

Max Power before clipping = 16.92Vrms in 8 ohms, 1Khz=35.8W
This is very good.

My dc offset problem seems also to be resolved. I'm will get the final results tonight after the amp is stabilized.

Everything is looking good.

In the mean time I will change the wiring around the FET to see if it improve the sound.
 
Aleph30 Offset

With the new 3.3K resistor for the current source of the input FET, I have near perfect offset on the right channel at <10mv.

The left channel is around 60mv. I will try to reduce it.

I re-arranged the wiring for the right channel. All FET have now their own wire and they all meet in a star fashion at the 6X0.47 ohms at the speaker output.

The sound improve with this mod. There is now more bass and it has more punch to it. I will do the same to the left channel. It probably also improve the DC offset at the output. The offset was higher before this mod.
 
Hey, guys

Another question on this hot Aleph 30 topic -
where should one connect the R0 (the 3ohm@3Watt resistor) - should that be on the main board to ground ( and that means two R0, one for each channel), should it be on the PSU board (a common one, or two serarate ones for each channel), or something else.

Tell me how did you implement it, your input will be highly appreciated.

Stan - wants to be safe when possible
 
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