I think they are referring to the "Pocket Class A". Love that thing. I built a lot of them last year at this time. They were very popular holiday gifts.
xrk971 Pocket Class A Headamp GB
xrk971 Pocket Class A Headamp GB
Thank you very much for the answers!
Twocents what is the PCA?
xrk971, can I use your schematic as a base for my owm design?
I would like to try to implement also a DAC directly on the PCB
Sure, please attribute the design to Hugh Dean and xrk971 on the silkscreen if you make your own PCB - and only for non commercial use.
Maybe this?
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US $21.85 5％ Off | High quality CM6631A USB to I2S digital interface/asynchronous sound card/audio module/XMOS DAC
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Hi Vunce,
I am evalutaing different chip, maybe a PCM2707 + I2S DAC (Like PCM1794 or somethings from analog device or other).
The problem is to find a USB-I2S converter not to complex.
I would like to power all amplifier throught USB
Hi Bambinz , its not a good idea to use USB to power your DAC+AMP combo as ground can be noisy.
In case of PCM1794 , you will need three other op amp for I/V conversion, i will recommend using OPA1642 or OPA1656 here but good old NE5532 does a great job. LME49721 can be used if you wanna go for USB power.
In case of CM6631 , feel free to ask me to customize the firmware if you need.
Cheers.
Hi Dibya, Hi xrk971,
Thank you very much.
Maybe instead of the PCM1795 I will use the ADAU1761 that integrate a DSP, so I can add filter or other things. I've used it before for in a work project ( I am electronic engineer, but my field is not the audio systems)
The firmware CM6631A should be programmed? Now I search some info about this IC
Another candidate is the SiliconLab CP2114-B02, can reach 48kHz, 24Bit.
Thank you very much.
Maybe instead of the PCM1795 I will use the ADAU1761 that integrate a DSP, so I can add filter or other things. I've used it before for in a work project ( I am electronic engineer, but my field is not the audio systems)
The firmware CM6631A should be programmed? Now I search some info about this IC
Another candidate is the SiliconLab CP2114-B02, can reach 48kHz, 24Bit.
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Hi ,
if source code is in readable C language I can help.
I once wanted to do xmos based usb to i2s but I left due to lack of knowledge in MIPS assembly. I am fine with x86 assembly thought. RISC type architecture like ARM and MIPS do behave differently than x86 processor.
I have source code and firmware flash tool for cm6631.
Hi Bambinz,
I use this USB to I2S board in one of my DAC’s. It works excellent and has lots of features and hookup options. Also, you can keep the “dirty” USB power separate from the “Clean” Dac side by powering the board with an external regulated psu.
I2SoverUSB - I2S over USB Audio
Thank you very much Vunce!
xrk971 I have used two LDO (One for the left channel one for the right channel) ADP7147 (High PSRR, low noise LDO regulator). In this LDO can be set the ramp up time by adding only 1 capacitor
I have used two LDO because to avoid unstability due to high capacitance!
In addition, where possible I have used 0603 component
xrk971 I have used two LDO (One for the left channel one for the right channel) ADP7147 (High PSRR, low noise LDO regulator). In this LDO can be set the ramp up time by adding only 1 capacitor
I have used two LDO because to avoid unstability due to high capacitance!
In addition, where possible I have used 0603 component
