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

[Ryssen]

1 board left (Right and Left).

All are gone now.

 

[albertli]

Does anyone try it with Hammond 193V?
Thanks

 

[xrk971]

193V has 1ohm DCR which is a bit on the high side, but it should still work.

 

[albertli]

X,
Thanks

 

[yogilla62]

Today I got the 5 pcbs from JLC ,And I only need 1 of them (one spare).
I thought I give away 3 of them.( You pay only for shipping).
This is revisison 1 of the board.
If you want one send me a P.M

If it is still up-to-date, I will gladly take one set

 

[Ryssen]

Sorry they are all gone.

 

[xrk971]

Looking forward to seeing LuFo's up and running out in the wild!

Thanks for your generosity Ryssen!

 

[albertli]

Hi X,
I revisit the second time of this thread and found that there are zener v 101, 103 n 105 looked different from your official schematic. Are they optional or essential?
Thanks
Albert

 

[albertli]

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

 

[albertli]

Forgot to post the picture

 

[albertli]

One more

 

[xrk971]

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!

 

[albertli]

Thanks for your reply.
The bias I set it down to 2A @20v B+.
Burning in now n very stable. I might let it sing late to night after I got home.
Albert

 

[xrk971]

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.

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

 

[albertli]

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

 

[albertli]

Hi X,
This amp makes astonishing life like imaging with my open baffle speakers.
Thanks for your hard work.
Albert

 

[xrk971]

Thank you for trying out the LuFo amp, AlbertLi. Your system looks amazing. So glad you are enjoying the sound.

Cheers,
X

 

[Vunce]

WOW!!
Beautiful setup Albertli, enjoy your newborn LuFo 🙂

 

[Plott]

Great setup Albertli, wish you happy listening with the LuFo

 

[JPS64]

@albertli


No need for EMI filtered AC inlet?


But please, cover the hot plug with shrink tubing!



JP