I want to make a pcb for TDA7377 with tone control circuit.I made a schematic, please check & let me know the modifications.
Tone Ctrl.JPG - Google Drive
Thanks
Tone Ctrl.JPG - Google Drive
Thanks
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Between the opamp output and the balance pot, otherwise you don't have a voltage divider, and you'll short the opamp when the pot is at the endstops.
You've got DC flowing through the bass pot wiper, but the opamp is FET input so you should be OK. Watch out for that, with bipolar opamps the bias current shouldn't be going through a wiper or you get loud crackles.
You've got DC flowing through the bass pot wiper, but the opamp is FET input so you should be OK. Watch out for that, with bipolar opamps the bias current shouldn't be going through a wiper or you get loud crackles.
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The first Opamp U1.2 must be bias to Vcc/2 since it only has a single supply (search Google for single supply op amp designs). If you're going to put this on a box, I suggest you separate the pcb for preamp/tone control circuit from the power amp. IMHO, it is much better if you're going to mount the tone control potentiometers on the box's panel together with its own pcb rather than adding wires to each potentiometers from the pcb (unless you already knew the box dimensions). Hope this helps. Thanks.
I'd go with 14.7K with a 100K pot.
But I'd use a 10K pot with 1.47K resistor. Lower resistor values = lower noise.
Similarly, I'd go with 10 kΩ pots for tone and volume.
I'd also switch the balance pot to a stereo pot. The way you have it, you'll get a mix of left and right channel current through the wiper of the balance pot. That'll degrade the channel separation.
I also suggest updating the opamps to something more modern. OPA2134 or LME49720 for example.
Tom
I'd also switch the balance pot to a stereo pot. The way you have it, you'll get a mix of left and right channel current through the wiper of the balance pot. That'll degrade the channel separation.
I also suggest updating the opamps to something more modern. OPA2134 or LME49720 for example.
Tom
Datasheet shows 1000uF on power rail as decoupling.
You have 10uF.
The 1000uF can cause problems if you want to use low power SMPS.
You have 10uF.
The 1000uF can cause problems if you want to use low power SMPS.
If you want cross fade instead of balance put 1K resistor in series with op amp outputs to pot and take outputs from between 1k and pot.
Another option is to put 1K in series with pot to ground.
Another option is to put 1K in series with pot to ground.
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