I got my kit a little while ago, and still haven't warmed up the iron to dig in to the project. I didn't buy the chassis, because I'm going to mount the amps to a bulkhead in a sailboat I'm refitting. I found some big flat heatsinks I'm hoping will work; I guess I'll find out soon enough. If not, I'll find bigger ones. 
There's a reference somewhere to "the new 2U UMS 8 hole pattern." Does anyone have specs for, specifically, the 3 holes for the transistors and board? I couldn't find that anywhere. Sure, I could measure it, but I thought I'd ask.
I plan to power the amps from the 12v 1000Ah battery bank. I have a step-up converter on my B1 that just works like magic. I'm hoping a pair of those step-up converters on the ACA's will work as nicely. Would I be able to control the power consumption by dialing the voltage down to, say, 16v? Most of the power is from solar, and there's just only so much of it.
I'll post cool photos, and ask more silly questions as I go.
Thanks!
There's a reference somewhere to "the new 2U UMS 8 hole pattern." Does anyone have specs for, specifically, the 3 holes for the transistors and board? I couldn't find that anywhere. Sure, I could measure it, but I thought I'd ask.I plan to power the amps from the 12v 1000Ah battery bank. I have a step-up converter on my B1 that just works like magic. I'm hoping a pair of those step-up converters on the ACA's will work as nicely. Would I be able to control the power consumption by dialing the voltage down to, say, 16v? Most of the power is from solar, and there's just only so much of it.
I'll post cool photos, and ask more silly questions as I go.
Thanks!
Thank you again for your kind reply.
So o checked and rechecked and all seems correct.
I cant find any shorts, the mosfets dont beep against chassis, any leg from them, all seems correctly oriented and i am still afraid to power it up lol...
As i dont have alligator connectors with me i am going to buy them and then i'll make the 1st power on.
Just to make sure i have this right, on the back on the speakers connectors, the red ones are the out+ from pcb right? So what is ground from the back pannel wires is the speaker + on the back? That is correct?
This is also chassis ground.
In terms of my security,
Yes. And yes it is confusing. The 'Red' output terminals are connected to the Ground wires.
Make sure it is like Step 35 of the build guide.
It conforms to the circuit diagram Step 1 that is '+ OUT' connected to 'ground'.
Alan
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Thank you for your reply.
So i really think i have all correct.
So next step is to power it on, quickly measure both channel bias and if is under 12v each, let it warm up for like 20 minutes and the dial in the bias.
Is this correct?
The DC conditions appear to be correct now which is 95% of the way there really. If the bias pre-set works correctly and is able to swing the voltage on those four resistors by a good amount (say down to 7v volts and up to 18v then your problem has to be either no continuity of the audio signal to the input coupling cap C3, or no speaker continuity from the output coupling cap to the speaker sockets. Or something like a short at the input or speaker sockets.
Ok, so the amp powers on and nothing exploded, melted, burned or killed me
I notice that on power on the voltage starts about 10-11v and goes up to about 12,4v then starts to drop, same thing in both channels. As i dont have crocodile tips i will have to wait until monday to get them and bias accordingly.
Anyway, even if more spoon fed i could not be, i am HAPPY \o/
Thanks to all that took the time to respond to my noob questions!
You all rock!
Now Luxembourg has a class A addict noob diyselfer!!!!
I notice that on power on the voltage starts about 10-11v and goes up to about 12,4v then starts to drop, same thing in both channels. As i dont have crocodile tips i will have to wait until monday to get them and bias accordingly.
Anyway, even if more spoon fed i could not be, i am HAPPY \o/
Thanks to all that took the time to respond to my noob questions!
You all rock!
Now Luxembourg has a class A addict noob diyselfer!!!!
Check/compare input and output wiring between the working and the non-working side. Could be something as simple as a shorted input, or something more complicated. Post some pictures.
My kit had the nylon standoffs too. They worked fine going into the heatsink, but be careful not to overtighten the screw that holds down the PCB. You can strip it out quite easily.
Congrats Motospark! Looks great! And I agree that matching leds of the preferred color it the way to go.
Best regards,
Rafa.
Friends, I have a quick question, specially reading this note from fred0
When I was building mine, the Source leg of Q2 beeped against the heatsink. I panicked, but upon reading the skematic, that is connected to ground. So I started checking, and due to the nature of my case, the Heatsinks are actually ground. The standoffs from the PCBs are also ground. And, while the anodized surfaces are NOT conductive, the sides which don't have the anodizing layer ARE also ground.
Is this is a problem and something to be avoided in the future? Is it common for the entire chassis to be 'chassis ground'?
Thanks in advanced,
Rafa.
When I was building mine, the Source leg of Q2 beeped against the heatsink. I panicked, but upon reading the skematic, that is connected to ground. So I started checking, and due to the nature of my case, the Heatsinks are actually ground. The standoffs from the PCBs are also ground. And, while the anodized surfaces are NOT conductive, the sides which don't have the anodizing layer ARE also ground.
Is this is a problem and something to be avoided in the future? Is it common for the entire chassis to be 'chassis ground'?
Thanks in advanced,
Rafa.
Thanks
Hi Rafa, thanks, I ended up purchasing a Blue LED kit from PartsExpress, it was only couple of dollars and came with 10 LEDs and pull down resistors, 100 and 470, I used them as is. They are a little bright but I like them like that.
Congrats on your Custom build, It looks beautiful.
Mark
Congrats Motospark! Looks great! And I agree that matching leds of the preferred color it the way to go.
Best regards,
Rafa.
Hi Rafa, thanks, I ended up purchasing a Blue LED kit from PartsExpress, it was only couple of dollars and came with 10 LEDs and pull down resistors, 100 and 470, I used them as is. They are a little bright but I like them like that.
Congrats on your Custom build, It looks beautiful.
Mark