IVX
Major Contributor
They used ADAU1701 with its ****** ADC, that's why SNR just 90db, actually, $1/2 ADC today offers SNR 105db(A), and I see no reason to save money on it.
If the capacitor fix drops noise another 6 dB over what's shown, that would get us to about 98 dB(A). Seems reasonably close to what you would expect from ADAU1701 converter specs (A/D 100 dB(A) + D/A 104 dB(A), both combined = 98.5 dB(A)). Swapping the ADC for one with 105 dB(A) would improve matters by 3 dB only, no doubt very welcome (300 µV counts as mediocre) but still not exactly earth-shattering.They used ADAU1701 with its ****** ADC, that's why SNR just 90db, actually, $1/2 ADC today offers SNR 105db(A), and I see no reason to save money on it.
They used ADAU1701 with its ****** ADC, that's why SNR just 90db, actually, $1/2 ADC today offers SNR 105db(A), and I see no reason to save money on it.
This is not a rotary encoder. It's a potentiometer with hard stops. The STM32 doesn't control volume, it is for LED indication. Look closely at the block diagram. The potentiometer connected to the ADAU via Auxiliary ADC Input.This is not a knob, it's a rotary encoder. Volume is controlled by the STM32 micro controller.
View attachment 110783
You can use a CY7C68013A board just $3. Another solutions is ESP8266 for control via wi-fi.you have to have USBi interface too i.e. buy it first ($84 for the original one)
a) this. b) For equipment not needing much power, an external "brick" PSU may be a nice solution, as long as it's not cr@ppy, because it keeps noise away from the internals. The problem is, many are cr@ppy... In the end, one gets what one has paid for (and that's the best case).Why would anyone even consider using mains powered products without safety and regulatory approvals ? Evaluation just stops there , product can not be used safely...
Yes of course it's manageable, but not necessarily "on the cheap". It seems to me, nowadays the most important thing is to issue a new model before the competition, with maximum features to minimum cost. Proper construction and quality, as long as it survives the guarantee period, comes second. The end product is then often a waste of good chips. Mass market has become like junk food, "the customer is not a p!g, he'll eat anything"... On the other end of the market, there are some who think they need to "ameliorate" reference designs without enough knowledge, with similar results....all that is manageable...
a) this. b) For equipment not needing much power, an external "brick" PSU may be a nice solution, as long as it's not cr@ppy, because it keeps noise away from the internals. The problem is, many are cr@ppy... In the end, one gets what one has paid for (and that's the best case).