The Alpha Big Boy with Buttah (ABBB) 52w Class A Amp GB

[xrk971]

Thanks for the info Hugh. That's a pretty slick DC protect system. Very hi-tech! Well done you guys!

Good to know there’s no unobtanium parts once again. 🙂

I have 8 of these guys to put to use. I've posted this info on the Alpha thread before, but if anyone needs a cheap cooler here you go. They were made to dissipate at least 130W on Xeon servers and have large copper pads on the bottom. Should be able to handle one mosfet per cooler I would think. Need 4 for an ABBB. I used these to test out my Alpha 20 build and they worked really well.

HP ProLiant CPU Heatsink DL580 DL980 G7 LGA1567 570259-001 591207-001 | eBay

Jwjarch, thanks for the tip. These are excellent heatsinks. Very compact and nice size copper pad. Only $7ea!

 

[loafimus]

gary s - 2 boards
jwjarch - 2 boards
Vunce - 4 boards
meanie - 2 boards
shattered_dream - 2 boards
yoaudio - 2 boards
md_Stryker - 2 boards
Roundtoit - 2 boards
sst4270 - 2 boards
chilly - 2 boards
Kokanee - 2 boards
evanc - 2 boards
a3cervo - 2 boards
markus22ch - 2 boards
barryblue - 2 boards
Andrewbee - 2 boards
Arthur - 2 boards
JRKO - 2 boards
pblossom- 2 boards
woodlands - 2 boards
loafimus - 2 boards

 

[Mistertaz]

Any idea of the approximate total cost per channel (excluding case)?

 

[jwjarch]

Jwjarch, thanks for the tip. These are excellent heatsinks. Very compact and nice size copper pad. Only $7ea!

No problem X. Happy to share such a great value for the money. Not sure if you can beat it. The Dells are nice too but not so inexpensive.

 

[xrk971]

Any idea of the approximate total cost per channel (excluding case)?

We have not done a detailed analysis yet but probably $150 to $250 depending on choice of component quality (Dale vs Yageo, and Silmic vs Nichicon, etc). Big ticket items in BOM are IXYS MOSFETs the LT4320’s and the 4x 15,000uF bulk caps. CPU coolers are another $25 to $50 and fans are $15 to $40 depending on quality. You can do it with a single Dell CPU cooler per channel for both MOSFETs and smaller passive radiator for cap Mx. 400VA to 500VA trafo is another $50 to $70.

 

[xrk971]

Verification of SSR Speaker Protection

Just wanted to let folks know that I am working on the SSR speaker protection circuit that jofland designed. The P2P verification build is under testing but I am trying to debug a potential miswire. I may have to make it using a home etched PCB which JPS64 did a quick layout for me. The SSR DC protection works, just trying to get the 2 second turn on delay to work now.

The P2P veroboard:

Using a DC-DC step up to make 37v which then gets reduced to 27.6v via a 15v+12v zener diode string:

Here is home etch artwork from JPS64:

 

[sst4270]

Yay! Progress. Keep up the great work X

 

[mordikai]

gary s - 2 boards
jwjarch - 2 boards
Vunce - 4 boards
meanie - 2 boards
shattered_dream - 2 boards
yoaudio - 2 boards
md_Stryker - 2 boards
Roundtoit - 2 boards
sst4270 - 2 boards
chilly - 2 boards
Kokanee - 2 boards
evanc - 2 boards
a3cervo - 2 boards
markus22ch - 2 boards
barryblue - 2 boards
Andrewbee - 2 boards
Arthur - 2 boards
JRKO - 2 boards
pblossom- 2 boards
woodlands - 2 boards
loafimus - 2 boards
mordikai - 2 boards

 

[xrk971]

SRR Speaker Protection Circuit Successfully Tested

I found an errant wire causing a short in my circuit. Removed it and the circuit works beautifully, as predicted. It has about a 2.5 second delay on startup, and a DC 9v battery applied to where the amp connects shut it off right away. A 1.5v battery also shuts if off. It takes the same 2.5sec delay to combe back up. The LED glows when the speaker is connected and working. During power off, the opamp works as low as 5v so if there shoul not be a turn off thump either, as it would catch it and prevent the turn off thump as well. I hooked it up to my XKi speaker pwered by current amp, the M2X. It works perfectly and adds no sound or noise of its own. Transparent as far as I can tell. So I think this circuit is good to go and JPS64 can finalize the circuit layout and produce the Gerbers for me to order the boards.

Thanks to jhofland for a great little SSR spaeaker protection circuit!

Testing here with XKi speaker and M2X amplifier:

Still using the DC-DC to simulate the 37v rail from the PSU.

 

[jwjarch]

Well done everyone! Thank you all for your collaborative efforts to bring another amazing project to DIYA!

 

[gtose]

gary s - 2 boards
jwjarch - 2 boards
Vunce - 4 boards
meanie - 2 boards
shattered_dream - 2 boards
yoaudio - 2 boards
md_Stryker - 2 boards
Roundtoit - 2 boards
sst4270 - 2 boards
chilly - 2 boards
Kokanee - 2 boards
evanc - 2 boards
a3cervo - 2 boards
markus22ch - 2 boards
barryblue - 2 boards
Andrewbee - 2 boards
Arthur - 2 boards
JRKO - 2 boards
pblossom- 2 boards
woodlands - 2 boards
loafimus - 2 boards
mordikai - 2 boards
gtose - 2 boards

 

[lung]

gary s - 2 boards
jwjarch - 2 boards
Vunce - 4 boards
meanie - 2 boards
shattered_dream - 2 boards
yoaudio - 2 boards
md_Stryker - 2 boards
Roundtoit - 2 boards
sst4270 - 2 boards
chilly - 2 boards
Kokanee - 2 boards
evanc - 2 boards
a3cervo - 2 boards
markus22ch - 2 boards
barryblue - 2 boards
Andrewbee - 2 boards
Arthur - 2 boards
JRKO - 2 boards
pblossom- 2 boards
woodlands - 2 boards
loafimus - 2 boards
mordikai - 2 boards
gtose - 2 boards
lung - 2 boards


Total 50 boards

 

[xrk971]

JPS64 tells me he is close. Doing some final checks and then the CAM post processing tomorrow morning. Here’s what it looks like:

 

[jwjarch]

X, I know the SLB is okay with flying leads from the SC5200 and SA1943, but what about the IXYS' from the amp itself. Is there any risk of oscillation if the leads to the molex get too long?

 

[xrk971]

Vunce and I have built several IXYS based amps with Molex connector flying leads now. Mine are 8in long and no problem at all.

 

[jwjarch]

Glad it's a proven method X! 😉 Really can't wait to get my hands on these boards. I'm debating building up my dual mono SLB's or saving the SLB components for this build. They aren't cheap! But, heck! May as well build both, right?!?! 😀

 

[gary s]

That PCB as shown is one hell of a professional looking PCB - a very big WELL DONE to JPS64 - absolutely beautiful and symmetric. Awesome!!!

 

[xrk971]

I just got the processed Gerbers from JP. The board has over 16k vias!!! I feel for the drilling machines.🙂

 

[Vunce]

That’s awesome news X!
What’s real comforting about the ABBB is the amplifier section itself has already proven to be a fantastic sounding design from those that built the BB.
Looking forward to this project 🙂

 

[xrk971]

The SLB portion has also proven itself on the 4 amps that we have tried it with (M2X, Alpha 20, MoFo, Glass Harmony). So it’s a nice package of proven technologies. The addition of SSR protection circuit is not completely new as a variant has proven itself on the Deltic.