My desktop powered monitors have developed mains leakage on their ground and it's time they (or at least their PSU and amp) went.
I figured I might do some DIY on it. I really like the look of the automotive style ICs like these:
https://www.infineon.com/cms/en/pro...grated-class-d-audio-amplifier-ics/ma2304dns/
However, it would be awfully cool if I can expand my options and then narrow them back down to something I can pick up in "dev module" or "eval board" format to... well evaluate it. Initially skipping PCB dev and starting breadboards.
I know all the main manufacturers make these chips so there is a wide range. I'm just trying to pick a few options to start on. If I search for this area on Amazon or AliExpress (where I would usually look for eval boards) I obviously get all manor of snake oil rubbish... where it seems that the colour of the capacitors has more value to the buyer than the actual facts.
I know that TI, infineon et. al. produce their own "Evaluation boards", but they are prohibitively expensive if you are only making a one/two off device for home use. Chinese dev boards are fine for this purpose.
Actual requirements:
Input: Ideally Optical SPDIF. Less ideally, I2S, not really helpful Analogue line in.
I only need 1 input but if two or three come with the IC, I might wire em up.
Output: 20W RMS a side would do. I'll have it drive the existing monitors initially and maybe upgrade to a 2:1 later. So an output channel capable of "sub out" would be ideal (line level or amplified at 20W)
I only need 2 (+1 sub) channel output. If the chip comes with 4, I might never hook them up or I might add them as surround (which opens a kettle of fish on the input formats, so lets leave that for now!).
Power supply. I have up to 10 Amps of battery power DC 12-14V range. When that isn't available I can use a quiet DC brick.
I figured I might do some DIY on it. I really like the look of the automotive style ICs like these:
https://www.infineon.com/cms/en/pro...grated-class-d-audio-amplifier-ics/ma2304dns/
However, it would be awfully cool if I can expand my options and then narrow them back down to something I can pick up in "dev module" or "eval board" format to... well evaluate it. Initially skipping PCB dev and starting breadboards.
I know all the main manufacturers make these chips so there is a wide range. I'm just trying to pick a few options to start on. If I search for this area on Amazon or AliExpress (where I would usually look for eval boards) I obviously get all manor of snake oil rubbish... where it seems that the colour of the capacitors has more value to the buyer than the actual facts.
I know that TI, infineon et. al. produce their own "Evaluation boards", but they are prohibitively expensive if you are only making a one/two off device for home use. Chinese dev boards are fine for this purpose.
Actual requirements:
Input: Ideally Optical SPDIF. Less ideally, I2S, not really helpful Analogue line in.
I only need 1 input but if two or three come with the IC, I might wire em up.
Output: 20W RMS a side would do. I'll have it drive the existing monitors initially and maybe upgrade to a 2:1 later. So an output channel capable of "sub out" would be ideal (line level or amplified at 20W)
I only need 2 (+1 sub) channel output. If the chip comes with 4, I might never hook them up or I might add them as surround (which opens a kettle of fish on the input formats, so lets leave that for now!).
Power supply. I have up to 10 Amps of battery power DC 12-14V range. When that isn't available I can use a quiet DC brick.
You might consider a FDA (full digital amp) like this one : https://www.aliexpress.com/item/1005001557158418.html?spm=a2g0o.productlist.main.11.759f170drlqgAT&algo_pvid=ba98dffd-a00c-48ff-80ed-e832b9eb38db&algo_exp_id=ba98dffd-a00c-48ff-80ed-e832b9eb38db-5&pdp_ext_f={"sku_id":"12000016581878008"}&pdp_npi=2@dis!USD!59.88!59.88!!!!!@211bf31616740494299272006d06c2!12000016581878008!sea&curPageLogUid=VRUWKhweUEVj
How about Zoudio? https://zoudio.com/
It's I2S capable for input. You'll need B+ power in the 20V order though, in order to get 20W out. Nothing will give you 20WPC from 12-14, unless it steps it up inside the box.
You also get programmable digital filters, for each of two, 20W outputs per stereo side for a total of 4 outputs. I think you can do 2.1, using the two bottom outputs to drive 1 speaker, but it may need to be DVC, which isnt that hard to find in a LF driver. Maybe the new version can do Parallel BTL; cant remember.
I've had two boards for a couple years now and they've been reliable. My bottoms are 18" drivers and the 20WPC X 4 goes plenty loud for me on each of two OB systems.
It's I2S capable for input. You'll need B+ power in the 20V order though, in order to get 20W out. Nothing will give you 20WPC from 12-14, unless it steps it up inside the box.
You also get programmable digital filters, for each of two, 20W outputs per stereo side for a total of 4 outputs. I think you can do 2.1, using the two bottom outputs to drive 1 speaker, but it may need to be DVC, which isnt that hard to find in a LF driver. Maybe the new version can do Parallel BTL; cant remember.
I've had two boards for a couple years now and they've been reliable. My bottoms are 18" drivers and the 20WPC X 4 goes plenty loud for me on each of two OB systems.
It was so close. But out of stock. Tried a second seller, same thing, they added, "Discontinued" 🙁 It's clearly the guts of some other box like a Fosi or SMSL. Most likely the 16x2 LCD display has gone completely out of fashion with blue OLED being the trend. So these "guts" probably weren't worth putting into a case and trying to sell as complete items.
Which is where I've decided to go. They are basic desktop monitors. A cheap DC powered optical input amp from Amazon will do fine. I have plenty on the DIY plate 🙂