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

[tonza75]

ScanSpeak D2908/7140 Beryllium Dome Revelator Tweeter I thought you used it, ok well good build anyway. It's to hot over here we scandinavians aren't used over 30°C this early over here.
Anyway 10 for build it's those things you can appricate when a lot of work gone into a finished project.

OK, so be illuminator 6640 used.

 

[pinnocchio]

OK, so be illuminator 6640 used.

No, using D2908/714000 in my build. Sorry, I had misunderstood you and thought you were talking of replacing all drivers with Revelator series. My bad..

Do

 

[Vunce]

I received my BB boards today
They look amazing! Interesting subtle changes compared to the prototype pcb’s.

Thanks again X for organizing this GB.



Vunce

 

[xrk971]

I can’t wait to see anothe Alpha BB come to life. Listening to mine lately after forcing myself to listen to a 60w Class D for 3 days straight. It’s a huge difference in quality of sound coming back to the Alpha.

 

[Vunce]

I can’t wait to see anothe Alpha BB come to life:

Me Too!!

X,
The Deepcool Gammaxx 300 and Deepcool S40 are currently the same price. The 300 has 3 pipes, the S40 has 4 pipes and they use the same fan. But, they both have a 130w rating.
I’m leaning towards the 4 pipe cooler.
Which one would you choose?

 

[xrk971]

The S40 sounds like an upgrade with 4 heat pipes, but I think they are smaller diameter pipes. Either way, I'm sure it will work fine.

 

[drpro]

Boards here also. Super nice, I may just frame them, why cover such beauty with a bunch of components!!

 

[xrk971]

The coolest thing is when you hold them up against back light. It’s basically transparent see thru riddled with vias. JPS64 did some special magic with them that’s for sure. I just rechecked the output noise. Still <100uV rms and silent.

 

[wtl]

X,
How much capacitance is needed for the BB power supply.
I have 2 500va 30v transformers 1 for each channel.
Would 40v rated caps be ok to use or am i better off using 63v caps.

Steve.

 

[xrk971]

I think if you have 4x33mF 50v per channel you are good to go. More is always better of course. Also, stringing it out as Hugh suggests in a CRCrCRC with smaller C can work. And if you have extra high voltage trafos, you can use larger R to drop the voltage and reduce the ripple. I am using 4x22mF CRC plus a second CRC with 4x10mF. I have no noise or hum on my B.B. with 100uVrms noise at the output.

 

[pcgab]

Me Too!!

X,
The Deepcool Gammaxx 300 and Deepcool S40 are currently the same price. The 300 has 3 pipes, the S40 has 4 pipes and they use the same fan. But, they both have a 130w rating.
I’m leaning towards the 4 pipe cooler.
Which one would you choose?

Just need a pair of those for a stereo BB?

for ~$23.00 USD that seems like a deal.

 

[pcgab]

X,
My BB boards arrived yesterday. They are damn nice boards!

 

[Vunce]

Just need a pair of those for a stereo BB?

for ~$23.00 USD that seems like a deal.

Hey Gab,
You’ll need 4 total, one per mosfet.
They are sweet boards

 

[pcgab]

Oh, right, one per output device. Cool.

What are you plans for PSU?

I'm pricing 33000uF 63v and 80v caps, maybe 4 per channel?

Transformer 500, 600va?

 

[pcgab]

Maybe one of these:

AN-6428 - 600VA 35V Transformer - AnTek Products Corp

 

[Vunce]

I currently have a AN-6430 Antek, the voltage is little high but I think with the CRCRCRC psu I can get it right. If that works, I only have to buy one additional transformer, Yahoo!!

 

[pcgab]

I currently have a AN-6430 Antek, the voltage is little high but I think with the CRCRCRC psu I can get it right. If that works, I only have to buy one additional transformer, Yahoo!!

Nice, I will keep an eye on your build. I'll likely do similar.

I need to wrap up a few other projects before I can dive in. My general plan is to build them as monoblocks, separate PSU chassis, and use them to power the LF of my main horn system.

 

[xrk971]

Just need a pair of those for a stereo BB?

for ~$23.00 USD that seems like a deal.

You will need four - back when I got them they were only $12ea. Seems to have doubled in price lately.

 

[yoaudio]

B.B boards received.
Thanks again!

 

[pcgab]

You will need four - back when I got them they were only $12ea. Seems to have doubled in price lately.

Yeah, Vunce reminded me that I need four. I'm not in a rush so maybe I can wait for a sale, though even at ~$23, they seem like a good deal.

I wish the cpu coolers didn't have the ends of the heat pipes exposed. Maybe I could make a cap to clean up the look a bit...

I could make a Delrin or PTFE cap, remnant pieces of both are inexpensive on eBay.

So many ideas, hahah