Pro Audio Design Forum

Thank you both Wayne and JR for the inputs. I have added a capacitor across the feedback resistor, and marked as DNP.

I haven't had the time to sit down and layout the board yet. Will be back shortly!

So one way of understanding the offset compensator is that the op-amp can output a voltage even if both input are tied to GND. To compensate for this drift, we use the compensator pin. Cool! I ended up attaching a generic 0805 capacitor to the pin 8 and 5. And I marked them as DNP. It is a good time...

Thank you very much for the feedback again! I added 100k ohm at the input (between the +ve side of the cap. and GND). I am figuring out what exactly are the PIN 5 and 8. TI's datasheet explains it's to compensate for the input offset voltage arising from mismatch from input stage. Unfortunately this...

Great, that makes more sense. I thought 160Hz high pass was eliminating too much low bass.
This is my schematic for now. I will add on the volume-knob and variable voltage resistor like you have drawn.

Will report back soon.

Almost done with my schematics. Thanks for making corrections and posting the image. Thanks! The RC filter has a cut-off frequency at 159.2Hz. This is using the values you have suggested (10kOhm and 0.1uF). Am I correct to understand this as any frequency below 159.2Hz will be filtered out? In other...

Ok here is my updated schematic. I have addressed these issues: 1. Added missing resistors at the output on the 2nd channel (R14, R15, R16) 2. Added an AC coupling capacitor (C11/C10) along with resistors for dc path(R6/R1). 3. Negative DC input no longer being fed back to non-inverting input 4. Cor...

There are also problems with the non-inverting input. It has no DC bias path to ground and should have a coupling capacitor in series with the input with a resistor to ground on both sides. Ok, I did a little bit of reading on coupling capacitor. At the input we need an AC coupling capacitor to rem...

The power supply bypass for the negative supply should have it's positive end grounded. It looked like you had pin 4 connected to +12V - it should go to -12V. The bypass for pin 4, V-, should connect to the - end of the cap. Doh, that makes a perfect sense now. Thank you for your patience. I am cor...

One thing I would like to clarify. The capacitors have negative end connected to GND. Is that what you were referring to in regards to reversed polarity?
Much appreciated.

Thanks for joining us. The board looks nice. If the board was routed from this schematic it may be hard to make all the corrections on the PCB. WRT the schematic the biggest problem I see are the supply connections around pin 4 of the 5534. The polarity is wrong should be -12V. The cap polarity is ...