Is this tone controller okay with 12v?

Audioguru again

Joined Oct 21, 2019
3,632
You show this extremely old (used 60 years ago) tone controls circuit already on another thread. It has a high signal loss because it does not use an opamp.
I never saw it use all the same capacitor values.
 

Audioguru again

Joined Oct 21, 2019
3,632
On your other thread about the CD8263 amplifier, we determined that it was wired as a mono bridged amplifier, not as a stereo amplifier. The old passive tone controls circuit will reduce the amplifier input signal too low.
 

Thread Starter

TieBravo

Joined Aug 21, 2021
50
An
You show this extremely old (used 60 years ago) tone controls circuit already on another thread. It has a high signal loss because it does not use an opamp.
I never saw it use all the same capacitor values.
Any possibilities this can be modified using a opamp ic?
 

Audioguru again

Joined Oct 21, 2019
3,632
Add a series coupling capacitor to the tone controls output to block its DC then connect a volume control to the coupling capacitor.
One of your amplifiers has DC on its input then a coupling capacitor must be added between the volume control and the amplifier input.
 

Thread Starter

TieBravo

Joined Aug 21, 2021
50
A
Add a series coupling capacitor to the tone controls output to block its DC then connect a volume control to the coupling capacitor.
One of your amplifiers has DC on its input then a coupling capacitor must be added between the volume control and the amplifier input.
AS I'm going to use this soldering, can i use a LM1036 opamp to make a stereo tone controller using modified Baxandall?
 

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KeithWalker

Joined Jul 10, 2017
1,933
Any possibilities this can be modified using a opamp ic?
Yes, it would work be be sure to not overdrive the attenuator chips. The signal voltage must be within VCC and GND at all times or they will be damaged. What attenuator chips are you planning on using and what are you going to control them with?
The safest way to do this would be to use one op-amp on the input of each channel to amplify, DC level shift and limit the input signal and another one on the output to compensate for the tone control circuit losses.
 

Ian0

Joined Aug 7, 2020
3,463
DId Mr. Baxendall get mentioned on the other thread, by any chance?
Did the obsolescence of the LM1086 also get a mention? By the same people?
 

Ian0

Joined Aug 7, 2020
3,463
You show this extremely old (used 60 years ago) tone controls circuit already on another thread. It has a high signal loss because it does not use an opamp.
I never saw it use all the same capacitor values.
Baxendall's circuit was published in October 1952, and this circuit predates it, so I'd say 70 years.
 
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