I'm building a new boombox & chose the TDA8920BTH for the amp because it was the right price & bridged it should provide plenty of power. The boombox is mono, with a single 10" mid/bass & a horn compression diver connected with a crossover. The amp is this more expensive of the 2x cheap TDA8920BTH boards on eBay, the blue one apposed to the red one that I've found a bit about here through searching.
I just got the amp in the mail today from Singapore & was expecting to just be able to wire it up bridged & start playing, but it looks like I need to do some soldering. But I don't understand what exactly it is that I'm supposed to do, so was wondering if anybody could shed some light on it?
These are the instructions on the bottom of the PCB. I assume I'm meant to solder a wire between the two pairs of contacts marked by the 'Connect' lines? But the two contacts in the 'Cut' circle confuses me.
This is the top of board that those contacts corresponds to. The 'Connect' lines would connect the yellow components (sorry I don't know what they are, they're labeled 470nJ 63) whilst the 'Cut' circle would cut one end of 2x of the 5.6k resistors.
Does this make sense? Also, this may seem like an obvious question, but in bridge mode do I have to feed the amp a mono signal (down either left or right) or can I feed it a stereo signal & it will combine them for me?
I just got the amp in the mail today from Singapore & was expecting to just be able to wire it up bridged & start playing, but it looks like I need to do some soldering. But I don't understand what exactly it is that I'm supposed to do, so was wondering if anybody could shed some light on it?
An externally hosted image should be here but it was not working when we last tested it.
These are the instructions on the bottom of the PCB. I assume I'm meant to solder a wire between the two pairs of contacts marked by the 'Connect' lines? But the two contacts in the 'Cut' circle confuses me.
An externally hosted image should be here but it was not working when we last tested it.
This is the top of board that those contacts corresponds to. The 'Connect' lines would connect the yellow components (sorry I don't know what they are, they're labeled 470nJ 63) whilst the 'Cut' circle would cut one end of 2x of the 5.6k resistors.
An externally hosted image should be here but it was not working when we last tested it.
Does this make sense? Also, this may seem like an obvious question, but in bridge mode do I have to feed the amp a mono signal (down either left or right) or can I feed it a stereo signal & it will combine them for me?
No instructions at all, only what's printed on the bottom of the board. I've messaged the seller, but it will probably be a day or two until I get a response (I think it's night time in Singapore right now).
I've also discovered that I might not even be able to power it with the 2x 12v SLA I was planning on using
Might have to shelf this one & buy a more appropriate one.
I've also discovered that I might not even be able to power it with the 2x 12v SLA I was planning on using
Might have to shelf this one & buy a more appropriate one.The chip/board needs a symmetric power supply; where it says ±24v that means you have to supply it with +24v as well as -24v (& ground obviously). Two 12v SLA batteries will give you +24v but you'll either need another two batteries to get the -24v (four batteries total) or alternatively use just two batteries but with something like a PT6650 to take some of the power from them & convert it into -24v (which would be inefficient & get hot).
I had no idea about this when I bought it, I thought ±24v meant it would work on *either* +24v or -24v, not that it actually needs both!
I've already started another thread asking for recommendations for a more suitable amplifier that will run from just +24v & drive a mono 8ohm load to 50W & above.
As I said, you could use two pairs of batteries (four batteries in total) with one pair supplying +24v & the second pair supplying -24v, or you could use just one pair of batteries but split the output so that one wire goes straight to the amp (+24v) & another goes to a PT6650 or similar to convert it to -24v & then to the amp. You can't connect +24v to both of the terminals if that's what you were thinking (I actually tried that before I understood what symmetric meant...).
AFAIK symmetric DC supplies aren't often used. The amp is more designed to powered by a centre tapped toroidal transformer, not batteries or an SMPS.
There's no point whatsoever putting symmetric DC through a bridge rectifier, because what you get out the other side will still be symmetric DC but with some voltage loss because of the diodes. It won't damage anything though, so the seller has marked & advertised the amp as being able to be powered by DC when in reality it only really makes sense to power it from an AC toroid.
I got this from Lost Eden.
http://i55.tinypic.com/2wq99u9.jpg
I really wish somebody is selling the upgraded version of this board using TDA8950.
http://i55.tinypic.com/2wq99u9.jpg
I really wish somebody is selling the upgraded version of this board using TDA8950.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.