Tda1557q

[mravlcax]

I have a question and it sounds like this... how to get the best sound quality out of this chip amp. Can it be better with moddifying just the circuit or the best thing is just to select other chip amp.

Greatings

[mravlcax]

I'm using this design TDA1557q and I have already made two gnds. One for PS and other for signal.

[Arty]

Might not be the proper place for it, but i would not like to open a thread for this.
Would someone be so kind to inspect this design, and tell if it will work or not?
I plan to build it without PCB, just simple point-to-point.

Parts list:
IC TDA1557Q
P1 ->10 K dual gang lin.
P2 -> 50 K dual gang log.
R1=R2 -> 10 K
R3 -> 1K
C1=C2 -> 100nF
C3=C4 -> 150 pF
C5=C6 -> 680nF
C7 -> 3700 uF /25 V elco
C8 -> 100nF
C9 -> 22uF /25 V elco

Supposedly it will be used to power a set of small computer speakers.

[pacificblue]

Curious way to realise the balance pot. What is the purpose of C1 and C2?
The muting circuit will probably work different from your expectations, but the amp as such will work.

[Arty]

uu my bad, i did not provide the description to the schema.

R1+C1+P1 (half of the stereo pot) provides a shelving filter to compensate the rolloff of the small speakers i intend to use.
same applys to R2+C2+P1 (otherhalf of the stereo pot) but only for the other channel on the amp.
C3 and C4 provides some filtering too, setting the high freq. rolloff.
C5+C6 are DC blocking caps,
C7 is reservoir cap,
C8 is to prevent oscillation as datasheet states
R3 and C9 supposedly reduce turn on plop, i have no clue if it will work or not as intended, actualy its just something many kits based on this or similar IC uses, and i only applyd it.
And P2 stereo pot is the volume controll.

The shelving filter is a BSC network, based on
Baffle Step Compensation
this article.

Have not built it, for me it seems a correct schematic, but..... I know my self, so i wait for comments

[pacificblue]

Ah, I see. The response of the shelving filter will depend on the setting of the volume pot. But the difference will be small enough to be negligible.

Yes, looks like a correct schematic.

[Arty]

Well supposedly 6 dBL it can do , i sure do hope i will hear the difference.
Gone see in max 1-2 days, i going to build it now.
not sure about the grounding schema, might work i guess