High End Tone Control

[EUVL]

Further to this discussion on EQ & Tone Control:

John Curl's Blowtorch preamplifier part II

I open a new thread to continue the discussion.

Thorsten, the stage is your ....


Patrick

[EUVL]

I made some search in google JP but could not find anything meaningful.
Could you give us a few pointers, if only to kick start the discussion ?


Thx,
Patrick

[EUVL]

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[analog_sa]

Assuming digital sources, isn't an analogue device achieving this a complete waste of time and effort?

[EUVL]

Good question. But what to do with tapes and LPs ?

And how to do it digitally (e.g. real time or off line) ?
Do we lose resolution (or more abstract SQ) in the process ?


Patrick

[Groove-T]

Originally Posted by analog_sa

Assuming digital sources, isn't an analogue device achieving this a complete waste of time and effort?

Digital is not perfect and Microphones and Loudspeakers are almost analog, so why not.
Second there is always the discussion, which pre amplifier sounds best or not and why this is the case.

And there is the question, how are the masters mastered and equalised ( anolog or digital) and what is the resulting sound quality.

For analog Records with have different equalisations, giving different sound balance and with 25 year old CDs the soundmix is also often very bright, since they wished to demonstrate the clarity of the newdigital medium.

[kevinh]

Rip the Disc's and Taped into a loss less digital format, 192/24 bit and then eq the program material using software on a computer. A good phono into A/d is needed.

There are good solutions for the cpu software-> USB -> I2S -> FIFO buffer _> D/A -> Amp

D Burwen has put the functionality of the Cello Audio Pallette into software (plus other functions, he was the designer of the Pallette).

BB_Home

This software is implemented as a Windows Media Player plug in (the DSP functions are encoded in Excel Spreadsheets) Windows has a loss less media file format. I have also installed a FLAC plug in for Windows Media Player. The settings for each recording can be stored so you only have to do the adjustment once for each recording.

Then for conversion from USB to I2S there is the exaU21 board.

http://www.exadevices.com/

The FIFO buffer project being done by iancanada on this thread, great looking project.

Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter


The Buffalo Dac from twisted pear or the RAKK Dac from K & K.

This would provide a wonderful digital front end to allow people to master their own music library to work with their system. As opposed to the system used by the recording engineer.


The flexibility we are just beginning to get to allow us to control our music libraries is a wonderful thing for DIY music lovers. IMO.


I had occasion to hear what the original Audio Pallette could do for records, having this capability abailable for 10% of the cost of the Palette (25 years ago) is amazing to me.

[Bonsai]

A well implemented Baxandall tone control is a wonderous thing. Feed it with a low source impedance and be circumspect about the boost and cut (20dB is easy to achieve, but 10dB is a better design goal) and they can add a lot to a system.

See Self's 'Small Signal Audio Design' for some good examples.

(I designed quite a few pre-amps in my 20's and always included Baxandall T/controls but my recent designs have not included these. Might be time to take a trip down memory lane again)

[wahab]

Originally Posted by Bonsai

A well implemented Baxandall tone control is a wonderous thing. Feed it with a low source impedance and be circumspect about the boost and cut (20dB is easy to achieve, but 10dB is a better design goal) and they can add a lot to a system.

Undoubtly , the best solution...

It should be mandatory in any serious preamp design , along with a defeat switch.

[Pano]

Tone controls are for sissies! Like putting milk and sugar in your coffee. Wimps.