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Main => Everything Else => Topic started by: BadMouth on September 21, 2018, 11:07:46 am

Title: Cheap little digital amplifiers
Post by: BadMouth on September 21, 2018, 11:07:46 am
I've been tinkering with audio stuff lately.  At first I ignored the cheap little digital amplifiers, but after checking out the datasheet for the TI chip most of them use I decided to order one to play around with.
https://www.amazon.com/gp/product/B01N1UHTU1/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1 (https://www.amazon.com/gp/product/B01N1UHTU1/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1)

(http://forum.arcadecontrols.com/index.php?action=dlattach;topic=158346.0;attach=371348;image)

I'm impressed for the price and size.  It would be more than enough power for an arcade cabinet.
It seems to lack the bottom end of the standard car A/B amp I was comparing it to (which probably has a little bass boost designed into it).
I didn't want to buy a power supply until some testing was done.  I ran it at 24v on a bench supply to make sure I was getting the full 50w per channel (peak).
Honestly it didn't sound much different on 12v.  Supposedly it can pull as much as 7.5A, but I didn't even break 1A in my testing which was only driving one channel.

Here is the datasheet for the chip: http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=tpa3116d2&fileType=pdf (http://www.ti.com/general/docs/lit/getliterature.tsp?genericPartNumber=tpa3116d2&fileType=pdf)
Title: Re: Cheap little digital amplifiers
Post by: Ond on September 21, 2018, 05:58:52 pm
That amp has a very flexible power supply spec, nice!
Title: Re: Cheap little digital amplifiers
Post by: Howard_Casto on September 21, 2018, 07:22:07 pm
Have to run across any units with a hookup for a small sub?   The speaker system in the racing rig are decidedly crap and I could mount that right in the dash. 
Title: Re: Cheap little digital amplifiers
Post by: BadMouth on September 21, 2018, 08:32:36 pm
Have to run across any units with a hookup for a small sub?   The speaker system in the racing rig are decidedly crap and I could mount that right in the dash.

Yeah, I also ordered one of these which utilizes 2 of the TI chips, but one bridged for a sub. 
https://smile.amazon.com/gp/product/B07BKYL3GC/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1 (https://smile.amazon.com/gp/product/B07BKYL3GC/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1)

It defaults to bluetooth input though.  You have to hold in on the volume knob, then an asian female voice says "line in".
I'm sure they make them without bluetooth.  It adds a treble adjustment which is nice.

Sunday I hope to do some more side by side comparisons with a solid old school 2x30w amp.
I think these will do ok for desk (at work) speakers I'm making, but the distortion climbs pretty fast as the output gets near its maximum.
I'm also going to build a boombox with some old car speakers, so not too worried about the distortion level on that.
Title: Re: Cheap little digital amplifiers
Post by: Howard_Casto on September 21, 2018, 09:16:30 pm
Cool man thanks.  I'll do a thorough search once I get a chance, which admittedly might be a ways off the way things are going.  I need to get the racing rig in a good, playable state before winter hits so I can work on some of the software that's been in a holding pattern since I stopped working on it.