12V DC gainclone?

[DigitalJunkie]

TDA7350 is another 12V option,sounds okay too. 11W x2,Plus it's bridgeable to ~22W per chip/channel.

[wahab]

Originally Posted by DigitalJunkie

TDA7350 is another 12V option,sounds okay too. 11W x2,Plus it's bridgeable to ~22W per chip/channel.

yes, bridge is a good option...
i just build a stereo gainclone using phillips TDA1558Q...
power max is 2 X 22W , all in one case, and it work very well..

TDA1558Q Datasheet pdf - 2 x 22 W or 4 x 11 W single-ended car radio power amplifier - Philips

[AndrewT]

the tda1558 is specified as 22W into 4r0.
Look at the datasheet.
For a supply voltage of 14.4Vdc it has a range of 15W to 17W, in bridged mode, into 4r0 load, with 0.5% distortion.
This is quite high and most specifications, that are not in car oriented, show maximum output power @ 0.1% distortion.
Phillips have not shown any data for 12Vdc supply nor any data for what losses to expect into various loadings.



This amp is more likely to be an 8.5W into 2r0 times four @ 0.5% distortion.
This is probably equivalent to 5W into 4r0 @ <0.5% distortion.
Bridging two of these giving about 10W into 8ohm speakers may give quite good performance.
The single chip could do stereo (two channel) 10+10W into 8ohms.

[star882]

Originally Posted by jaycee

If you have experience - if you don't and it's for a car, there is dangerous current involved that can melt and burn anything and start fires in a fraction of a second.

If you were going to go this far, you'd want to build a symmetric supply, which means winding a transformer, and also requires a 'scope for setting dead time.

You'll really want a fuse or two regardless of whether or not there's a boost converter. And a single rail will work just fine with a BTL design. The TI hybrids are all single rail.

[wahab]

Originally Posted by AndrewT

the tda1558 is specified as 22W into 4r0.
Look at the datasheet.
For a supply voltage of 14.4Vdc it has a range of 15W to 17W, in bridged mode, into 4r0 load, with 0.5% distortion.
This is quite high and most specifications, that are not in car oriented, show maximum output power @ 0.1% distortion.
Phillips have not shown any data for 12Vdc supply nor any data for what losses to expect into various loadings.



This amp is more likely to be an 8.5W into 2r0 times four @ 0.5% distortion.
This is probably equivalent to 5W into 4r0 @ <0.5% distortion.
Bridging two of these giving about 10W into 8ohm speakers may give quite good performance.
The single chip could do stereo (two channel) 10+10W into 8ohms.

yes, distorsion is somewhat high, that s why i first proposed to use a TDA2040....
i did build a TDA1558Q amp a few days ago, and i did choose
the bridge configuration as at low power, it allows a distorsionless
sound even at 2 X 10 W...
anyway, the four amps needed to build a stereo bridged amp
are all in the same casing, and the circuit is very simple to implement...

[irishpatrick33]

Alright guys I have some newbie questions regarding the schematics on those two amps.

TDA1558Q: on fig. 4 of the stereo BTL scematic, pins 4 and 15 have no designation... yet pin 9 specifically states it's not connected. So is there some I am supposed to do with them that's no explicit? There also is a suggestion on how to lower low frequency distortion by applying a 1.5v zener diode or two diodes at pin 15... considering I have no idea what I am even doing with pin 15, in what fashion do I apply one or two diodes?

TDA2040: it mentions that the C1 and C2 capacitors are DC coupling caps. Now the only kind of DC coupling caps I saw at digikey were surface mount. I assume that's not what I am looking for. So will ordinary caps work? Are they just simply explaining the caps function? Or is DC coupling the exact type needed?



I'm sure those questions are going to indicate just how green I am. This should be a wonderful disaster.

[wahab]

pin4 : as displayed in the quad channel version, you can connect
a 100 uF CAP from this pin to ground to improve power supply rejection..
in my try, i did add it...

pin 15 : forget about it , as phillips explanation miss something.
if a zener or two diodes are connected there, the circuit stop working..

dec coupling caps are normal caps, in that case, electrolytics...

if you can find a TDA1558q, i think this circuit is more practical than
the TDA2040....lot more of power, vastly simpler and so on...
i tested the two and i retained the former for the kind of purpose
i bilt it, i.e, as a pc amp....

[irishpatrick33]

Originally Posted by wahab

pin4 : as displayed in the quad channel version, you can connect
a 100 uF CAP from this pin to ground to improve power supply rejection..
in my try, i did add it...

if you can find a TDA1558q, i think this circuit is more practical than
the TDA2040....lot more of power, vastly simpler and so on...
i tested the two and i retained the former for the kind of purpose
i bilt it, i.e, as a pc amp....

pin4: I will be making the stereo schematic. So does that just got to ground? Or is it left unhooked?

I bought two of each chip. Just in case I blow something up. Which is pretty likely.

[Rodeodave]

Switchmode Power Supply For Car Audio

[wahab]

Originally Posted by irishpatrick33

pin4: I will be making the stereo schematic. So does that just got to ground? Or is it left unhooked?

I bought two of each chip. Just in case I blow something up. Which is pretty likely.

you can leave pin4 unconnected , that s what i made myself
in the first try, and it worked perfectly...
later, i did connect a 100 uF cap from this pin to ground, with the positive of the cap to pin4, of course...
you can see in the quad version schematic how it is connected..

you did manage to find this circuit easily?...
in another thread, a guy that was looking for the same
kind f amp did write that it was obsolete...
anyway, it should work flawlessly if you respect the
schematic, which is simple...

good luck in your try !!