Thread: All-in-one Atom330/ION project

The reason I think my amplifier power consumption estimates are, at least, in the right ballpark, is that you can buy 4x50W radios and nav systems and they work just fine off a regular radio harness. If their power consumption is, indeed, 200W at 12V (over 16 amp, and that's just for the amplifier itself), then that would certainly exceed harness' wire gauge allowance for current capacity. I'm putting 10A fuses pretty much everywhere, so if there is too much power draw, I should see them blow pretty quickly.

You beat me to it, my next question was going to be, what type of fuse you planned on using with that amplifier. I think you'll be ok if you use 10A fuses though. I just didn't understand why you were going with that relay module, when it looked like your own calculations called for more amps bases on the amplifier specs.

Oh and by the way, I ended up ordering that TDA7850 with Denoiser amplifier from ebay for a project currently working on, so I am keeping a close eye on your worklog. Interesting enough, I asked the seller what type of fuses he recommended and the answer was, he didn’t know. I’m still optimistic that I made the right choice based on your review.

The only reason I used a relay module is to be able to arbitrarily delay amplifier power on. However, I tried running the amp directly from the "ACC circuit" (on my test bench, it's just a 12V line with a power switch). TDA7850 Denoiser suppresses all noises VERY well. There's barely any noises when the USB sound card is not initialized. I might do away with the relay module altogether if the pop is bearable - it all depends on how it fares in the car. I'll try to put the whole thing together tonight and post some pics.

It's ALIVE!!!
I finally put everything together:

All components installed:


Powered up and running Win7:


The "battlefield":


Unfortunately, first generation BlackBox does not fit Lilliput 669GL very well - I had to cut out part of the top cover to accomodate for the PCB. The PCB does not stick out that much, it's just there's a lip between the monitor shroud and rest of the box - the PCB is as big as the shroud, so, naturally, the rest of the box needs to be trimmed:

yay!! now to just get it to the car..

Nice job

I still get a thump from the amp - I have no idea why. Here's my setup:

I have a relay that's connected to the computer via USB. It's controlled via a serial interface. I wrote a simple windows service that sends the ON command when windows boots up (or resumes) and OFF when windows shuts down, sleeps, hibernates etc
The amp's ground is always connected, and the positive is connected to the battery line through the relay. When windows starts up, the relay gets turned on and the amp gets power from the battery line.
Here's the strange part - during my testing, I hooked up the amp to the "battery" line on my test bench. When I turn on the power supply, the amp is turned on before the computer is turned on (because of the startup delay of DCDC-usb). Surprisingly, in this situation, there's very little thump or noise. There's somewhat of a pop when the USB sound card gets activated though. When the amp is hooked up through the relay, there's a pop and also some static noise for about half a second when my windows service starts, kind of like having your radio turned to static and then cranking the volume from low to high. The whole thing takes less than half a second and then there's no noise and the amp starts working OK.
I'm going to try to mute the sound card before turning on the amp and then unmute it after - maybe that will help. I'm also going to make the service dependent on Windows Audio Service, though uninitialized sound card doesn't make that much noise according to my previous tests, as described above. Anyone have any other ideas? I could upload a short video so you guys can hear the thump sound - it's not the same thump I used to hear in my other amps.

nivanov, nice project, very impressive. I'm sure that you will figure out on how to iron out all the gremlins.

I wish I had an idea on what's going on here. The only thing that come to mind for noise, is if all your ground points are not solid. I also used a usb creative SB card in the past (not any more), which also made a thump when it turned on/off. So to fix this I added a 3" 16g gnd wire from one of the motherboard's screw standoffs to the back of the enclosure, soldered to a gnd tap then was grounded to my vehicle's seat belt bolt with 8"10g. Then the thump was gone. Also my enclosure was made from aluminum.
Other than that.....I don't know....sorry.

I'll keep a eye on this cool project though, to see where it goes.........Good luck.

Originally Posted by RAWPWR

nivanov, nice project, very impressive. I'm sure that you will figure out on how to iron out all the gremlins.

I wish I had an idea on what's going on here. The only thing that come to mind for noise, is if all your ground points are not solid. I also used a usb creative SB card in the past (not any more), which also made a thump when it turned on/off. So to fix this I added a 3" 16g gnd wire from one of the motherboard's screw standoffs to the back of the enclosure, soldered to a gnd tap then was grounded to my vehicle's seat belt bolt with 8"10g. Then the thump was gone. Also my enclosure was made from aluminum.
Other than that.....I don't know....sorry.

I'll keep a eye on this cool project though, to see where it goes.........Good luck.

All my ground loop noises are taken care of by onboard ground loop isolators of the amplifier, so I don't think ground loop is the issue - besides, that noise really doesn't sound like a ground loop. Thanks for the idea though - I'll keep you posted!