Adding new sound HW

By Leonardo Padial

Expert (73)

Leonardo Padial의 아바타

09-02-2010, 19:34

We have diferent devices now, as PSG, SCC, OPLL... Some files from other formats can play in this devices across SW converters.
The question is: If posible add one new device/s for do more easy the reproduction of standar formats existing today ?.
Today is posible get cheap ADC, DAC and Codec with 12 to 32 Resolution bit, and Sampling Rate from 8Kbit/s to 192K/s see:

http://focus.ti.com/analog/docs/dataconvertershome.tsp?familyId=82&contentType=4&DCMP=TI_Error&HQS=Other+OT+error_p_dc

Too have programable devices can do operational support, and processor with great power. But, is posible improve with only DAC or Codec ?

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By Leo

Paragon (1236)

Leo의 아바타

09-02-2010, 20:57

Hola Leonardo,

If the question is improve DAC or improve codec , i answer codec.

Because the DAC quality will be spoiled accross MSX internal mixer and i dont like separate jack output.
Also now adays when we speak about good dac , we need good source that is to say high bitrate , msx may not be able to do this.

If would also say for DAC , that a s/p dif output , purely digital, is cheap and high quality no dac needed.

must have : to be compatible with at least some existing hardware.

One improvement i can think of :
One DSP that also drives through IOs pins an SD card , so music can be played in DMA between SD and DAC through codec and Z80 cpu not loaded.

See , coupling 2 hardware extension or more allows DMA's , we can think of coupling ethernet and audio codec to do an internet radio ( low sound quality here so no need of good dac)

i like this link , interesting for any hardware developper :
http://www.stm32circle.com/hom/index.php

By Leonardo Padial

Expert (73)

Leonardo Padial의 아바타

10-02-2010, 22:10

In the case of select Codec can be http://focus.ti.com/lit/ds/symlink/pcm5310.pdf for example

If ADC+DAC is selected can be http://focus.ti.com/lit/ds/symlink/ads8254.pdf + http://focus.ti.com/lit/ds/slas420a/slas420a.pdf for example

In both cases is needed one 16 bit procesor for non load the Z80. I all cases I am talking of 16 bits for sound samples.

Four chanel can simular one real 2D sound field. The samples and its rate can be into Flash or RAM for adding in each chanel by the 16 bits porcessor.

The system mush be easy to interface (CPLD) with Z80, and program similar to one PSG.

By Leo

Paragon (1236)

Leo의 아바타

11-02-2010, 06:27

this codec is fine.
these DAC+ADC : i dont like it , they are not audio specific , no volume control so you are not
having full range of SNR , the sampling rate of 1MHz is over specified for adc . these are not
audio dac+Adc in fact.

i also like :
http://www.st.com/stonline/products/literature/bd/13012/stv83x8.pdf
it is for TV and cheap 5$ , has one adc and 5 dac for 5.1 output , many
algorythms , equalizer , gain volume control , I2C interface, 2vrms DAC output ,
natural ring tone (midi files) , ..

and :
http://www.st.com/stonline/products/literature/ds/13365.pdf
with power amplifier class D included for 2w output , basic sound processing
like multiband equalizer, volume , 3D effects on stereo output .

also:
http://www.st.com/stonline/products/literature/ds/9622.pdf
just audio processor , not codec, but has parallel interface
ready to interface to cartridge port .

By Leo

Paragon (1236)

Leo의 아바타

11-02-2010, 13:57

One cool feature could be : FM transmitter for earing MSX sound output on your FM radio receiver , wireless !

By Leonardo Padial

Expert (73)

Leonardo Padial의 아바타

11-02-2010, 20:35

Other option is the Audio 4 chanel-16 bit ADC: http://focus.ti.com/lit/ds/symlink/pcm4204.pdf
with the Audio 4 chanel-16 bit DAC: http://focus.ti.com/lit/ds/symlink/pcm4104.pdf

The FM transmitter for earing MSX sound output on your FM radio receiver is one good option to include. But, what FM-modulator chip we can use ?

By Leo

Paragon (1236)

Leo의 아바타

11-02-2010, 22:11