Best chip for digital tone control in high-end preamp ?

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i would like do build a new high-end preamp, as the potentiometers of my actual design are going to die now after about 20 years.

as i would like to avoid potentiometers for the new design, i'm looking for the "best solution for high quality tone control" without using potentiometers.

which chip (or circuit) does the best tone control, to be used for high-end audio?

regards
bongo
 
If you are doing analog input to analog output, then why do "digital" tone control? Adding ADC and DAC in the signal path will not do you any good. Stick with an analog circuit, and use digital potentiometers in place of the traditional ones.

If you are already in the digital domain, then consider something like the (now kind of old) TAS3103. This is a DSP that doesn't require writing any DSP code, you just configure the various processing blocks (filters, mixers, etc.). You will still need to do a fair bit of microcontroller coding work.

You may be able to avoid the microcontroller if you choose the analog circuit with digital potentiometers, as you can find some digital pots with step-up and step-down inputs, which you can interface directly to buttons or a suitable rotary encoder.
 
Best chip for digitally controlled analog tone control in high-end preamp ?

maybe, the title was misleading!

what i'm looking for is a chip (or a circuit) to be inserted to the analog path (between source selector and volume control) to either do treble/bass correction or equalization.
this has to be done at the best possible quality. therefore i'm not sure if it's the better way to use a fully integrated solution, or a legacy solution with op-amps and filters, replacing the potentiometers with integrated digital potentiometers.

what do you recommend?

the whole thing has to be controlled digitally, as i have a small cpu on the unit anyway.
 
There are chips that do tone control with digital control, just search for "tone control" at digi-key to find examples. However, they do not have great audio specs. You will probably do better with a traditional circuit using high-grade digitally controlled potentiometers. I don't have specific suggestions for the pots, but several people here have built digitally controlled attenuators, so you can probably find what you need.
 
People sure do use them, and many would be surprised with who is using them. There is no harm in employing a tone control, as it can alleviate some of the brightness in recordings, or at least tailor the contour to what the listener desires at that time. The issue isn't so much the tone control, but, rather the implementation thereof and the negative effects that lesser circuitry can have on the cumulative fidelity, if we view it in that light. Good tone controls do not turn the highs into fizzy indistinct pink noise, nor do they relegate the low frequency domain into loose mud. Once room treatment has been addressed to the point that the listener can live with it, a tone control can set the final mood~ the tone itself. I think if people put more time into careful design of the tone control circuitry, they could save themselves some money on esoteric concentric ratio silver cabling spun by the fairies, silver & gold in oil capacitors with fancy labeling and valueless audiophile blue-tack tweaks.
 
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Some of the digitally controlled potentiometers could be used in a Baxendall circuit. We are only talking about a few dB of lift or cut here for fine tuning an already decent system

That's how I've got here, I was looking for Baxendall circuits using LM1973 (triple digital pots). I have two of these and I have no clue how to calculate the values for Baxendall parts.
 
Stick with an analog circuit, and use digital potentiometers in place of the traditional ones.
, which you can interface directly to buttons or a suitable rotary encoder.

I designed a PC controlled mixer and used digital pots for volume and tone controls.
It worked very well but it is important that the DC levels are kept within 0 to 5volts or you will get distortion and/or clicking in the audio stream.
I used a PIC18f4550 to control the mixer via USB. The PC had volume and tone control sliders on it.
 
If anyone is interested, post #18 has the updated version.
http://www.diyaudio.com/forums/chip-amps/199130-usable-tone-control-2.html

By the way, the schematic shows a row of SPST switches for tone adjustment only because that is all the TI Tina spice program has available. Of course practically any type of switch arrangement will work, I'm using two 2P23T rotary switches on mine.
Mike
 
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