Aksa Lender P-MOS Hybrid Aleph (ALPHA) Amplifier

..and black edition. I don't know, maybe that tinted acrylic would be better than any of these.


Why do you want to hide the gorgeous details? Show it off.
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Founder of XSA-Labs
Joined 2012
Paid Member
This is interesting. Matched PNP in SMT package.

https://www.mouser.com/datasheet/2/308/NST65010MW6-D-775558.pdf

Although specs say current gain matching to within 10% whereas we hand match Hfe to typically 1%.

KSA992 also available in SOT23 package - it’s called FJV992MTF.

https://www.fairchildsemi.com/datasheets/FJ/FJV992.pdf

The KSC1845 is available as SOT23 and called FJV1845PMTF

https://www.fairchildsemi.com/datasheets/FJ/FJV1845.pdf

The front end of the Alpha and the Aleph CCS could theoretically be shrunken down to the size of large postage stamp if all SMT parts were used.
 
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Founder of XSA-Labs
Joined 2012
Paid Member
I am curious what rail voltages builders of the Alpha 20 and Alpha BB are actually running at? There is a large amount of voltage sag with linear trafos and it seems to me, no matter how I try, I end up always a volt or two below recommended rail voltage. Also, if you are above, is the heat output manageable?

I recently bought a pair of 22VAC 300VA Anteks, hoping to get a solid 27vdc under load of 1.6amps. After the CRCRCRC, I am getting 25.6v. This is for a high output variant of the Alpha 20 that I am testing - just seeing if pushing higher voltage and increased cooling via CPU coolers and fans can work to boost power output.
 
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With the 22V transformer, you get 26.4V plus U use CRCRCRC power supply. With the 3pc R you burn up some power also. I hope you not using any high-value resistors there to burn up more power. Your 25.6V is absolutely normal with your setup.
When you buy a transformer to regular Class A bias calculation(not talking about Alep X where the total bias is over 7A per channel) 22ACV x 1.2 under load =26.4V DC.