Lm3886+ tone control

I have seen a LM3886 with a feedback circuit to reduce the gain bandwidth of the chip at high frequencies to avoid oscillation and to help overcome mains induced impulse noise .


But not a "tone control" ?


What is the resistance value on the potentiometer ?
 
kenwood ka3700

attachment.php

You may apply the same on LM3886
 

Attachments

  • bass treble.JPG
    bass treble.JPG
    49.5 KB · Views: 727
I recommend a separate OPamp with NFB frequency dependent control.
There is a bridge circuit for a passive regulator. But it requires additional reinforcement before or after.
Is it bad form to offer a set with Ali? 🙂
 
here is a Question

any one seen a LM 3886 schematic with a tone control nested in the feedback chain ?
Many chip amps like this are only stable above a certain noise-gain, so you have to figure out the minimum noise gain of your feedback network at HF to check if its workable. The LM3886 quotes gains of 10 or more as being stable - the treble-cut would be main issue I think.

The other issue is power consumption in the network components - you may have to compromise the network impedance higher to prevent burning out pots, which may increase noise. Also high signal voltages place more demand on component linearity - with a fixed gain you can just use 2 metal film resistors to set the gain and these are the only components where linearity is directly contributing to performace. Line-level signals are much less demanding on component properties.
 
images
It is simple to turn on: a conventional bridge tone block is supplemented from below with an electrolytic capacitor and connected to the amplifier output through a low-resistance divider of 1:10 resistors. An NFB resistor is connected from the output side of the regulator. Resistor and capacitor going to ground are excluded. Additional resistors can be used to limit the regulation of the pots.
I am not responsible for the outcome, property damage or personal injury 🙂
 
Last edited:
And it is the most stupid thing to come out of Japan yet (the kenwood). Were they out of op-amps ? I've seen servo's using op-amps in 1973.

geeez !
Clearly you never listened to one ...
yes there is pros and cons to talk about but if its stable and speaker cables are not 15 meters each,
then yes sounds superb and extra super clean the cleanest you will ever get in an integrated amplifier implementation......