Tone control circuit critique

Hi,

It's becoming an endless story.

I added a volume pot after the buffer OPAMP and then I added a gain of 10

Click to expand...

--> gain is 11

Now that you put the pot after the buffer you have the already explained:
* volume control influences sound
* sound setup influences the volumes

Still missing one power supply capacitor.

The output resistor has nothing to do with pot noise, it's to compensate for stability issues caused by capacitive load (cable).
But I doubt the 10R is enough. Look into Opamp's datasheet.

Mind your junction dot issues.

Mind that the sound control circuit is inverting. This might cause problems in combination with other sound equippment.

Klaus

Enzy said:

I added a volume pot after the buffer OPAMP and then I added a gain of 10...

Click to expand...

Perhaps it is better to add the volume control just before the second op-amp; the resistor at the output of the 2nd opamp has no big role but will help in stability.

Enzy;
these tone control circuits require a low and/or fairly constant source impedance.

The way you wired the volume, the impedance will vary as you change the volume control from almost zero at both extremes, to 2.5K at midpoint.

Hi,

@schmitt trigger:
Thanks for correcting me. I´ve now corrected the value in post#19

Klaus

KlausST said:

Hi,

With the pot at the output you have 0Ohms source impedance at very quiet and very loud position, but 2.5kOhms (corrected) at center position.
This will influence sound quality, don't be surprised if it sounds dead at center position but good at quiet/loud volume.

Klaus

Click to expand...

Thats not an option so I added it before the first buffer.

Hi,

I didn't say "at the signal input" nor did I say "before the filter"
I said "just before the first buffer" ...
How can I say it more clearly?
Maybe "at pin 3 of the first Opamp"?

Klaus