Hello Guy,
I’m currently working on a project for a Mobile Boom box where I’m going to use the ADAU1701 as DSP for Crossover and EQ. The output signal of it will be connected to a TPA3255 amplifier board.
I need a Volume control for the signal before the AMP. First I thought I could just use the DSP and a Potentiometer hooked up to its software parameters. But as I know now it isn’t a good idea since the output resolution is limited and by outputting a lower V -peak-peak there will be less Audio resolution at lower Volume. So I thought I could use a OPAMP for that. Is that a good idea or are there any other/better solutions for that?
As for the OPAMP volume control I thought about a Rail to Rail OPAMP with a Pot in the feedback line of it.
I would like to place the Potentiometer for Volume control a little away from the circuit so I can controll it easily. But i think long leads between OPAMP and feedback resistor could have a bad influence on the function. Like some capacitance or inductance caused by the long wires …
My 2. Solution was to use a PSVC (Power supply volume control). I’ve read a paper from Texas instruments about it’s advantages and it sounds very promising. But the only way to do this in a Mobile application is to use a DC-DC Converter… which many say they have a bad impact for Bass power (or is that just for Step Ups from 12v to eg. 36V?). Maybe a big capacitor on the output of the DC-DC Converter could solve that problem?
If you read this far firstly that’s for taking your time : ) I hope my sentences are clear enough to understand since am not native English speaker ^^
Thanks for your help beforehand
I’m currently working on a project for a Mobile Boom box where I’m going to use the ADAU1701 as DSP for Crossover and EQ. The output signal of it will be connected to a TPA3255 amplifier board.
I need a Volume control for the signal before the AMP. First I thought I could just use the DSP and a Potentiometer hooked up to its software parameters. But as I know now it isn’t a good idea since the output resolution is limited and by outputting a lower V -peak-peak there will be less Audio resolution at lower Volume. So I thought I could use a OPAMP for that. Is that a good idea or are there any other/better solutions for that?
As for the OPAMP volume control I thought about a Rail to Rail OPAMP with a Pot in the feedback line of it.
I would like to place the Potentiometer for Volume control a little away from the circuit so I can controll it easily. But i think long leads between OPAMP and feedback resistor could have a bad influence on the function. Like some capacitance or inductance caused by the long wires …
My 2. Solution was to use a PSVC (Power supply volume control). I’ve read a paper from Texas instruments about it’s advantages and it sounds very promising. But the only way to do this in a Mobile application is to use a DC-DC Converter… which many say they have a bad impact for Bass power (or is that just for Step Ups from 12v to eg. 36V?). Maybe a big capacitor on the output of the DC-DC Converter could solve that problem?
If you read this far firstly that’s for taking your time : ) I hope my sentences are clear enough to understand since am not native English speaker ^^
Thanks for your help beforehand
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.