Keantoken's Aurum-X 300w Amp with LatFETs

[xrk971]

The prototype verification boards have been ordered. Once these are checked out and determined to be working, we will have a GB - it would be good to gauge some interest in this amp. I'll start a GB thread to gauge interest.

GB thread here to check for level of interest.

https://www.diyaudio.com/forums/group-buys/354359-aurum-300w-class-ab-amp-gb.html#post6201104

 

[xrk971]

Prototype bioards are in. There is some surgery to correct for an error in the FE board that was caught until after fabrication was started. The boards are impressive though. The MB is huge and heavy 2oz copper, 2mm thick, ENIG. A stereo boardset weighs 1lb.

Thank you JPS64 for a beautful layout.

Now the hard and expensive work of assembling the verification build begins.

 

[wesayso]

Stop taking pictures and just build it up .
Just kidding, I can't wait to see this one come to life. Eager to hear your impressions on it.

 

[Cambe]

 

[xrk971]

Update: I am starting to order the big ticket items. The Exicons (on private GB with friends who are also getting it for another project), also, the two Antek AN-6458’s order has been placed. Bulk PSU caps next. Then usual small parts BOM from Mouser. I ordered a revised FE board that corrects earlier error. That should be here in a few days.

This is not an inexpensive project. Exact opposite of my FH9HVX.

 

[xrk971]

Note that there is a two pair Exicon outputs option with 63v rails 200w version of this amp. That can save a little cash and keep trafo smaller (45v), caps at lower voltage rating of 80v vs 100v, and chassis smaller as well.

 

[zman01]

X,

Good to know that you are marching ahead. Will stay tuned...

 

[xrk971]

Here are the changes From Keantoken for 63v operation with two pairs of latFETs for 200w:

Here are the bias components changed for 63V:

80V -> 63V

R27 12k -> 10k
R36/39 5.6k -> 4.7k
R28 82k -> 68k
R13 18k -> 15k
R30 15k -> 12k
R6/7 82k -> 68k
R4 27k

 

[xrk971]

Good news: Vunce is going to be doing the verification build with me - he will follow the 200w 63v path though as he has a massive Toroidy quad secondaries trafo and a 200w Class AB chassis all ready to go.

Two sets of eyes and soldering irons is always better than one!

Welcome aboard, Vunce!

 

[Vunce]

Yeah, this should be a fun ride X!
I’ve got the FE board parts list completed.
Another night for the MB, my eyes are crossed

 

[zman01]

Good news: Vunce is going to be doing the verification build with me - he will follow the 200w 63v path though as he has a massive Toroidy quad secondaries trafo and a 200w Class AB chassis all ready to go.

Two sets of eyes and soldering irons is always better than one!

Welcome aboard, Vunce!

200w is also a lot of power, and looks like good use of that big toroid you got Vunce .

Look forward to action soon!

 

[xrk971]

Hi Vunce,
Thanks for building the shopping carts in Mouser! It’s hard work and requires careful eyes. This is another way that we get parts sorted out when someone else has to pick the parts.
It’s all part of our well-honed process for delivering high quality verified PCBs for folks to have a successful build the first time.

 

[AKSA]

Very nice pcb, JP/XRK, and wonderful Vunce will be adding to his stable of thoroughbred amps with the Aurum.......

Hugh

 

[keantoken]

Sorry, that list is incomplete (my fault) and you put the wrong schematic with it.

80V -> 63V

R4 33k -> 27k
R6/7 82k -> 68k
R13 18k -> 15k
R26 10k -> 8.2k
R27 12k -> 10k
R28 82k -> 68k
R30 15k -> 12k
R36/39 5.6k -> 4.7k

 

[xrk971]

Thanks for catching that...

For the FE power supply, would it be ok to use an Antek AN-0225 (25VA) to get 50v, and skip the clever add/subtract using the secondaries and auxiliary windings of the AN-6458?

 

[thimios]

Good news: Vunce is going to be doing the verification build with me - he will follow the 200w 63v path though as he has a massive Toroidy quad secondaries trafo and a 200w Class AB chassis all ready to go.

Two sets of eyes and soldering irons is always better than one!

Welcome aboard, Vunce!

If you are looking for beta testers,i'm still here.

 

[xrk971]

Hi Thimios,
Would love to have you but I only got 5 boards and they are all spoken for.

 

[thimios]

Yeah, this should be a fun ride X!
I’ve got the FE board parts list completed.
Another night for the MB, my eyes are crossed

Hi Thimios,
Would love to have you but I only got 5 boards and they are all spoken for.

Ok, good luck!

 

[Vunce]

Thank you thimios!

 

[Vunce]

Hi Keantoken,
Since my main transformer only has 45v secondaries, I need a solution to get the power for the FE section. I was thinking of using two smaller 50v transformers, one for each channel, to accomplish this. Your thoughts?

Thanks,
Vunce