About the transistor tone control i posted earlier.. considering its low output swing (+-5V), I think it would be better to lower the boost/cut db to about +-8dB or thereabouts...with original values the boost/cut is about +-18dB. I dont think we generally need this much...
i will try to recalculate values for +-8dB boost/cut and a center frequency of 1KHz according to this :
i will try to recalculate values for +-8dB boost/cut and a center frequency of 1KHz according to this :
An externally hosted image should be here but it was not working when we last tested it.
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One thing, -/+8db isn't very much if you are talking 20kHz and 20kHz frequency points. At say 100 hz the boost/cut will be very low indeed.
There is an opamp tone control using 100k pots in this Philips application note. If space isn't an issue then Doug Self Precision Preamp tone stage is brilliant because it has adjustable turnover frequencies. Its by far and away the best tone stage I have ever seen and used.
There is an opamp tone control using 100k pots in this Philips application note. If space isn't an issue then Doug Self Precision Preamp tone stage is brilliant because it has adjustable turnover frequencies. Its by far and away the best tone stage I have ever seen and used.
Its very subjective really but those do look respectable enough curves.
The problem with all these type of circuits is that they alter the frequencies a long way to the side of where you really want the boost or cut. For example if you want to boost around 30 Hz then even frequencies as high as 300hz get some boost too. You can't really escape that with this type of circuit though.
The problem with all these type of circuits is that they alter the frequencies a long way to the side of where you really want the boost or cut. For example if you want to boost around 30 Hz then even frequencies as high as 300hz get some boost too. You can't really escape that with this type of circuit though.
for schematic from post number 2 http://www.diyaudio.com/forums/solid-state/176367-2-band-transistor-tone-control.html#post3672246 and for use with 30V PSU ,do i have to change any component values?
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Hi Maouna,
I just stumbled across this thead agian and thought I'd add my $0.02.
I'm not sure why you would want to build such an old design, nostalgia maybe? But this a pretty bog standard Baxendall circuit, and in my opinion that design leaves a lot to be desired. Worst thing about it is its' inherently shallow slope filters which usually can't even achieve a 3dB/octave slope. Because of that issue, attempting to make adjustments to bass or treble frequencies will also modify the mid-band, and that is not what we normally want. For more info, check this out: http://www.rane.com/pdf/acceler.pdf
Mike
I just stumbled across this thead agian and thought I'd add my $0.02.
I'm not sure why you would want to build such an old design, nostalgia maybe? But this a pretty bog standard Baxendall circuit, and in my opinion that design leaves a lot to be desired. Worst thing about it is its' inherently shallow slope filters which usually can't even achieve a 3dB/octave slope. Because of that issue, attempting to make adjustments to bass or treble frequencies will also modify the mid-band, and that is not what we normally want. For more info, check this out: http://www.rane.com/pdf/acceler.pdf
Mike
OK, but don't expect too much. Here's mine: http://www.diyaudio.com/forums/chip-amps/199130-usable-tone-control.html and the improved version with accelerated slope filters starts at post #18.
Mike
Mike
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