"quiet" chip amp but more power than tda7294

[abraxalito]

The actual maximum for a standard car chip design (the many "12v" bridge amp styles) is 14.8vdc, which is what a car does with the engine on.

Slightly OT I know, but...

I suggest you take a look at some of NXP's offerings - TDA8566 comes to mind. The maximum is higher than 14.8V - 18V is where they'll mute but the smoke doesn't come out until quite a lot higher than that.

Automotive is a very harsh environment because the electrical stuff needs to survive 'load dumps' where there's a spike of 45V for a few mS.

However, some of them are designed at the RV/marine spec of 13.5vdc.

In either case, 20vdc = smoke (if actually driving a real speaker for some time).

I've not played with the chip but if its like the NXP TDA family it'll mute above 18V and hence won't play anything.

 

[danielwritesbac]

I have ordered the part, I will have to figure out where the PS needs to be connected (I will only need one for both this and TDA7297, right?)

thanks for helping out this novice.

The preamp didn't come with sufficient power filtering onboard, but I've got a plan, and its an easy one!

You can use your TDA7297's 13v power supply for both the amp and preamp. Just put a diode, like a 1n5405, at the preamp (diode's stripe faces towards the preamp, in series with v+). That'll take your 13v down to 12.3v for the preamp. It will also cause a really easy version of CRC filtering.

Like this:
13v Power supply > cable > TDA7297 board > cable > diode > NE5532 board at 12.3v


P.S.
Having used the same power supply as the amp, now your NE5532 preamp has two ground connections, power and audio. So, try to get all of the wires between the amp and the preamp, exactly the same type, gauge and exactly the same length. I suggest thermostat wire from the hardware store.
Just in case. . .
If that wasn't enough, you can try cutting through one of the ground cables that goes in-between amp and preamp, so that you have only one ground cable connecting the two boards.

My samsung N150 is super quiet, I have a USB DAC connected (ELE EL-D02) to amp.. . .

Unless there's something wrong with the Samsung's onboard sound, its RealtekHD should be able to beat the quality of the ELE's PCM2704.
However, if you need an inexpensive USB device that will be suitable to amplify, try a C-Media based "USB sound card" (that's the search term--don't search for DAC) and you can identify C-Media easily because of their weird advertisements that involve multi-channel sound claims, when actually there just an ordinary stereo output jack (and a microphone/linein jack too).

 

[gychang]

The preamp didn't come with sufficient power filtering onboard, but I've got a plan, and its an easy one!

You can use your TDA7297's 13v power supply for both the amp and preamp. Just put a diode, like a 1n5405, at the preamp (diode's stripe faces towards the preamp, in series with v+). That'll take your 13v down to 12.3v for the preamp. It will also cause a really easy version of CRC filtering.

Like this:
13v Power supply > cable > TDA7297 board > cable > diode > NE5532 board at 12.3v


P.S.
Having used the same power supply as the amp, now your NE5532 preamp has two ground connections, power and audio. So, try to get all of the wires between the amp and the preamp, exactly the same type, gauge and exactly the same length. I suggest thermostat wire from the hardware store.
Just in case. . .
If that wasn't enough, you can try cutting through one of the ground cables that goes in-between amp and preamp, so that you have only one ground cable connecting the two boards.

Unless there's something wrong with the Samsung's onboard sound, its RealtekHD should be able to beat the quality of the ELE's PCM2704.
However, if you need an inexpensive USB device that will be suitable to amplify, try a C-Media based "USB sound card" (that's the search term--don't search for DAC) and you can identify C-Media easily because of their weird advertisements that involve multi-channel sound claims, when actually there just an ordinary stereo output jack (and a microphone/linein jack too).

thanks so much, I will follow this when the preamp arrive.