Aksa Lender P-mos Hybrid Aleph (ALPHA) Class A Amp GB

[xrk971]

Hi Watchtmouse,
Glad the boards made it you in good condition. Happy soldering!

 

[xrk971]

ALPHA 52W BB GB interest list

Please edit and add your name and quantity desired and ceramic TO264 insulators if needed below. I will need at least 10 people to show interest before ordering.

Cost will be $60/pair (keep in mind they are beautifully designed big 240mm x 130mm, 2mm thick FRP with double-thick copper and ENIG finish). Shipping cost for a pair of boards in the US will be $8, Canada $17, and everywhere else is $24. Yes it high due to weight of the boards coming in at 10oz for the package. TO-264 ceramic insulator pads are $2/set of 4.

pelayostyle - 1 set
pcgab - 1 set bb, 2 sets TO-264 insulator pads
vvs07 - 2 sets bb, 4 sets TO-264 insulator pads
emynet - 1 sets bb, 2 sets TO-264 insulator pads

 

[drpro]

ALPHA 52W BB GB interest list

Please edit and add your name and quantity desired and ceramic TO264 insulators if needed below. I will need at least 10 people to show interest before ordering.

Cost will be $60/pair (keep in mind they are beautifully designed big 240mm x 130mm, 2mm thick FRP with double-thick copper and ENIG finish). Shipping cost for a pair of boards in the US will be $8, Canada $17, and everywhere else is $24. Yes it high due to weight of the boards coming in at 10oz for the package. TO-264 ceramic insulator pads are $2/set of 4.

I have to confess not seeing/knowing how to edit and post alongside the others wanting PCB

I would like to be added to the list.

drpro BB 1 set, 2 sets TO-264 insulator pads

Thanks
David

 

[xrk971]

Alpha B.B. GB list:

pelayostyle - 1 set
pcgab - 1 set bb, 2 sets TO-264 insulator pads
vvs07 - 2 sets bb, 4 sets TO-264 insulator pads
emynet - 1 sets bb, 2 sets TO-264 insulator pads
DrPro - 1 set bb, 2 sets TO-264 insulator pads

 

[wtl]

X Can you put me down for
wtl - 1set bb, 2sets TO-264 insulator pads.

Steve.

 

[yoaudio]

Alpha B.B. GB list:

pelayostyle - 1 set
pcgab - 1 set bb, 2 sets TO-264 insulator pads
vvs07 - 2 sets bb, 4 sets TO-264 insulator pads
emynet - 1 sets bb, 2 sets TO-264 insulator pads
DrPro - 1 set bb, 2 sets TO-264 insulator pads
wtl - 1 set bb, 2 sets TO-264 insulator pads
yoaudio - 1 set bb, 2 sets TO-264 insulator pads

 

[markus22ch]

Alpha B.B. GB list:

pelayostyle - 1 set
pcgab - 1 set bb, 2 sets TO-264 insulator pads
vvs07 - 2 sets bb, 4 sets TO-264 insulator pads
emynet - 1 sets bb, 2 sets TO-264 insulator pads
DrPro - 1 set bb, 2 sets TO-264 insulator pads
wtl - 1 set bb, 2 sets TO-264 insulator pads
yoaudio - 1 set bb, 2 sets TO-264 insulator pads
markus22ch - 1 set bb, 2 sets TO-264 insulator pads

 

[xrk971]

We are at 9 sets now on B.B. GB - very close to the 10 I need to start production. I think we will get there soon so if you have your name on the list please PM me your PayPal info, quantity needed, and country to ship to.
Thanks,
X

 

[xrk971]

Alpha B.B. GB list

pelayostyle - 1 set
pcgab - 1 set bb, 2 sets TO-264 insulator pads
*vvs07 - 3sets bb, 6 sets TO-264 insulator pads
emynet - 1 sets bb, 2 sets TO-264 insulator pads
DrPro - 1 set bb, 2 sets TO-264 insulator pads
wtl - 1 set bb, 2 sets TO-264 insulator pads
yoaudio - 1 set bb, 2 sets TO-264 insulator pads
markus22ch - 1 set bb, 2 sets TO-264 insulator pads

I was just testing the Alpha BB this morning to check for oscillations at 5Mhz as suggested by Keantoken as a possibility. No evidence of it, here is 39vpp into 8ohms and then zoomed into and around 20ns/DIV:

 

[Cambe]

Yo X,
Put me down for a pair of BBs and insulators to suit.
Is their a BOM and Schematic for them?

Regards,

Cambe

 

[xrk971]

ALPHA BB GB update:

pelayostyle - 1 set
pcgab - 1 set bb, 2 sets TO-264 insulator pads
*vvs07 - 3sets bb, 6 sets TO-264 insulator pads
emynet - 1 sets bb, 2 sets TO-264 insulator pads
DrPro - 1 set bb, 2 sets TO-264 insulator pads
wtl - 1 set bb, 2 sets TO-264 insulator pads
yoaudio - 1 set bb, 2 sets TO-264 insulator pads
markus22ch - 1 set bb, 2 sets TO-264 insulator pads
Cambe - 1 set, 1 set of TO-264 insulator pads

Schematic:

PCB Placement:

BOM is here.

 

[mrk7]

Hi X,
Just confirming that I received my boards and ceramic pads.
Definitely sweet looking boards!
Thanks for organising the GB!

PS - Thought I'd add some paraphernalia from the Commonwealth Games that my home city just hosted as the title seemed fitting

 

[xrk971]

Mrk7,
Glad they arrived safely. I was worried those ceramic pads might be fragile but seems like the boards did a good job of protecting it.

 

[ekidnah09]

pelayostyle - 1 set
pcgab - 1 set bb, 2 sets TO-264 insulator pads
*vvs07 - 3sets bb, 6 sets TO-264 insulator pads
emynet - 1 sets bb, 2 sets TO-264 insulator pads
DrPro - 1 set bb, 2 sets TO-264 insulator pads
wtl - 1 set bb, 2 sets TO-264 insulator pads
yoaudio - 1 set bb, 2 sets TO-264 insulator pads
markus22ch - 1 set bb, 2 sets TO-264 insulator pads
Cambe - 1 set, 1 set of TO-264 insulator pads
ekidnah09 - 1 set bb, 1 set of TO-264 insulator pads

 

[drpro]

Up to 12 boards, YES!!

 

[drpro]

I am seeing 36vdc for the supply, though I haven't been following the 20w version build closely, I believe a transformer plus CRC type supply is needed here. Will a 25vdc xformer make it or is perhaps a 28vdc a better choice.\
Thanks

 

[xrk971]

I think a 28vac will be better as at full load you will get about 3v sag and it will be 36v. I am using 25vac trafo and it’s nominally about 30vdc under load. Need at least a 400VA per channel though. 300VA may work but you would be running at 2/3rds the current rating.

 

[xrk971]

For the folks getting the ceramic insulators, 1 set is 4 pieces enough for a stereo amp. Seems like people are ordering double sets. There are 20sets in the above order and I do not have enough left. So I might have to reduce your insulator orders to 1 set per pair of board.

 

[drpro]

Someone on the Swap side has a 800va @ 25vac X at a nice price. Oh well, just a thought.

Please change my order to 1 set. I thought I needed 2 sets for a stereo build.

 

[xrk971]

Maybe an 800Va won’t sag so much and could just work fine rongetbyou 35v rails.