Hi,
originating form the simple question (see below) of how to have a silent, high quality volume control & input selection I have decided to build an passive µController based, arduino compatible preamp input selection & volume control. Stay tuned! PCBs will come in the near future (I really need it).
To give you an image of the whole system I have drawn an image:
An Arduino compatible CPU is driving the whole system. It will have plenty of outputs for LEDs and plenty of inputs for buttons, rotary encoders or even analog potentiometers. The decision to base it on Arduino is to make programming as easy as possible. There is plenty of help out there to programm it to the specific needs.
The basic input selection can switch between a number of balanced or single ended inputs. For each input it is configurable if it is balanced or single ended.
The output can be balanced or single ended – according to your needs.
To convert between single ended and balanced there will be an an single ended to balanced converter. This module will be plugable in some way so that you can choose the technolgy you like (opamps, discrete or whatever).
The volume control will be an plugable module too - since currently there is a hot debate if LDR/chips or stepped attenuators are the way to go.
If needed a balanced to single ended converter can be attached after the volume control. But most probably this be not part of this design.
The beginning:
everybody seems to agree in this forum that using relays for analog input switching and volume control is the absolute best way to achieve the best signal quality.
Ok, sometimes potentiometers are better or have other advantages or disadvantages than relay based attenuators.
But in the end if you do not want to reduce the singal quality as minimal as possible it is the way to go.
But I am looking for digital (CMOS based) chips which do a comparable job. Does anybody now any analog switches and volume controls which achieve and extraordinary signal quality. Since there is no reason to introduce parts which have a higher distortion or THD level than your actual amp.
Any suggestions?
originating form the simple question (see below) of how to have a silent, high quality volume control & input selection I have decided to build an passive µController based, arduino compatible preamp input selection & volume control. Stay tuned! PCBs will come in the near future (I really need it).
To give you an image of the whole system I have drawn an image:
An Arduino compatible CPU is driving the whole system. It will have plenty of outputs for LEDs and plenty of inputs for buttons, rotary encoders or even analog potentiometers. The decision to base it on Arduino is to make programming as easy as possible. There is plenty of help out there to programm it to the specific needs.
The basic input selection can switch between a number of balanced or single ended inputs. For each input it is configurable if it is balanced or single ended.
The output can be balanced or single ended – according to your needs.
To convert between single ended and balanced there will be an an single ended to balanced converter. This module will be plugable in some way so that you can choose the technolgy you like (opamps, discrete or whatever).
The volume control will be an plugable module too - since currently there is a hot debate if LDR/chips or stepped attenuators are the way to go.
If needed a balanced to single ended converter can be attached after the volume control. But most probably this be not part of this design.
The beginning:
everybody seems to agree in this forum that using relays for analog input switching and volume control is the absolute best way to achieve the best signal quality.
Ok, sometimes potentiometers are better or have other advantages or disadvantages than relay based attenuators.
But in the end if you do not want to reduce the singal quality as minimal as possible it is the way to go.
But I am looking for digital (CMOS based) chips which do a comparable job. Does anybody now any analog switches and volume controls which achieve and extraordinary signal quality. Since there is no reason to introduce parts which have a higher distortion or THD level than your actual amp.
Any suggestions?
