LuFo Amp - 39w SE Class A from 28v Rail

Hi X,
have my version running on one channel. I have two 2sk1530 for the 240 and have the numbers as below.
Please advise if it's not as function
Vd 6.5v
Vs 2.11v
B+ 22v
Temp. @1530. 32c
@1014d 31c
Heatsink 28c
I did check the square wave and all looks good.
Regards
Albert
 
Forgot to post the picture
 

Attachments

  • IMG_20211201_112441457.jpg
    IMG_20211201_112441457.jpg
    996.8 KB · Views: 310
Hi Albert,
Nice work! I am not familiar with the 2SK1530 MOSFET but it looks like it’s working for you. The Zener across the gate to source is optional and to protect the gate from over voltage. The Zener is only on the MOSFETs. The JFET has no Zener as it messes up the steady bias current. What is your bias current?

Congrats!
 
Last edited:
Looking forward to hearing about your listening impressions.

I just got a batch of the new LuFo PCBs with all corrections made and mirror image silkscreen for left and right channels.

1001903d1638402949-lufo-amp-gb-2116a3be-4a71-4cf3-ac66-fb173c23e09d-jpg


I also just got the new Aksa Lender M2X boards with the revised 55v DCDC converter that now uses a discrete MOSFET.

attachment.php
 
Last edited:
Hi X,
Been living with this amp for two full days. It sounds close to my 2A3 n 300BSe, very smooth and relax. Sopranos are glorious, silky smooth. I really appreciate the phenomenal bass it creates, it goes so low and detail. Highs are good too. I purposely took down the 2sk180 amp for this, no regrets. I even head to head compare with my F4. Guess what will I do next. Eh....I might go for the headphone amp��
Thanks
Albert