I recently purchased a set of Tannoy V4 speakers to run with a Quad 405-2 amplifier. I'm an electronic engineer with lots of experience with digital electronics - however I'm fairly new to the world of audio.
The Quad 405-2 amplifier has no controls or variable attenuator on it, so requires an external volume control. The amp currently takes a 0.5v input - I plan to convert it to a standard 1.5v input.
So, I need to make a box that will:
- Provide volume control
- Provide adjustable balance (L/R)
- Provide adjustable bass/treble levels
- Allow for input selection of line level analogue inputs (PC/Mp3 player/etc)
As digital electronics is an area I'm familiar with, I plan to have:
- A graphic LCD display showing current settings
- A rotary encoder and user interface for the graphic LCD
- Presets, selectable with a remote control
I've been searching for chips that provide volume/balance/tone control through a digital interface (such as SPI or I2C). I have found several chips which look suitable, however the datasheets all mention 'car audio' rather than 'hifi audio'. I'm concerned that I could spend a few months designing and making this product, then find that it degrades the audio signal so much that it is unusable.
Does anyone have any experience with any of the below chips, or if not, do the specifications look suitable for home audio?
PT7313 - I2C control of volume, tone, gain and input
LC75342 - SPI control of volume, tone, gain and input
TDA7313 - SPI control of volume, tone, gain and input (mentions hifi, but no distortion figures)
The only digitally controlled part I could find that has excellent specifications and would definitely be suitable for hifi applications is the PGA2311 - however this doesn't provide any control of bass or treble. If the other options are going to distort the signal too much I could just use the EQ built in to the MP3 player/PC/etc, however I would prefer if the preamp had it's own settings.
Any thoughts or opinions are much appreciated!
Cheers,
Andy
The Quad 405-2 amplifier has no controls or variable attenuator on it, so requires an external volume control. The amp currently takes a 0.5v input - I plan to convert it to a standard 1.5v input.
So, I need to make a box that will:
- Provide volume control
- Provide adjustable balance (L/R)
- Provide adjustable bass/treble levels
- Allow for input selection of line level analogue inputs (PC/Mp3 player/etc)
As digital electronics is an area I'm familiar with, I plan to have:
- A graphic LCD display showing current settings
- A rotary encoder and user interface for the graphic LCD
- Presets, selectable with a remote control
I've been searching for chips that provide volume/balance/tone control through a digital interface (such as SPI or I2C). I have found several chips which look suitable, however the datasheets all mention 'car audio' rather than 'hifi audio'. I'm concerned that I could spend a few months designing and making this product, then find that it degrades the audio signal so much that it is unusable.
Does anyone have any experience with any of the below chips, or if not, do the specifications look suitable for home audio?
PT7313 - I2C control of volume, tone, gain and input
LC75342 - SPI control of volume, tone, gain and input
TDA7313 - SPI control of volume, tone, gain and input (mentions hifi, but no distortion figures)
The only digitally controlled part I could find that has excellent specifications and would definitely be suitable for hifi applications is the PGA2311 - however this doesn't provide any control of bass or treble. If the other options are going to distort the signal too much I could just use the EQ built in to the MP3 player/PC/etc, however I would prefer if the preamp had it's own settings.
Any thoughts or opinions are much appreciated!
Cheers,
Andy
