hey everyone !
i’m looking for adc and dac for audio
no big needs. mono, medium quality, better if it could be cheap.
what chip would be good to use ? i’m actually realy lost when searching for them and comparing one to others
Are you looking for a DAC/ADC for use with a PC (over USB) or with a microcontroller?
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the project is actually to try looping things with eeprom, probably gonna change for an arduino or something
The usual cheap DACs are MCP4822 and MCP4922. The latter are larger (14 pin DIP vs 8 pin) and use an external voltage reference vs. internal. Unless I got that backwards. They’re dual DACs. There might be single DAC versions but the dual ones are what I’ve mostly seen. 12 bit, not so great linearity (INL is 2 LSB typical, 12 LSB max), but anything better’s likely to cost at least twice as much.
For ADC I really only have used the built in ones on an Arduino.
I used a MCP 4921 and a MCP3201 in my KOSMO audiohacker project (beware, the schematic in that thread still has many mistakes, I never updated it!!). I would say the chips are okai and I am able to record and loop some seconds with arduino and an external SRAM chip. But I somehow lost motivation for my project and I am currently only using the module as a bit rate reducer (it should have been something like the 2ms freez…) But I would recommend looking at the original audio hacker board which is the one I based my board on, there are already some cool libraries and stuff, like a tiny sampler e.g. 
would it be better for me to use an arduino mega as big fast eeprom ?
I would recommend an external SRAM, because there you get 1Mb for ~3€ instead of just 4k(?) on the Mega, if I remember correctly. Also the total number of writes into eeprom is limited, so if you want to record more than a few times, it won’t be a good solution. You can get the SRAM to “remember” its content during times without power by adding a little battery and then only write the addresses of the stuff you recorded in EEPROM. There is an example for this in the audiohacker library. Without knowing more about what you want to do, it is hard to give more advice
the original idea was to make a simple looper, that could be syncronised with stuff. you can only launch the start of the recording. it automatically ends after 16 beats for example. it avoids the part where you have to be ultra precise with the in/out of the loops (otherwise it unsync easily)
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Okay, then forget about EEPROM
While it is easy to use EEPROM in the Arduino, it does have a limited life. EEPROM is specified to handle 100,000 read/erase cycles. This means you can write and then erase/re-write data 100,000 times before the EEPROM will become unstable.
makeuseof.com
As I said before, I would suggest to have a look at this audiohacker project of a 3 track looper and take it from there The only “unusual” part is the SRAM chip, but you can get it from arrow for ~3€ and they don’t even have shipping costs!
If you want it as a Kosmo module (and are located in mainland Europe), I would be happy to send you one of my spare boards to experiment
Or you could simply get a normal loop pedal for guitars etc. and program an Arduino to trigger it in sync with some clock. That would have even better sound quality and longer recording times!
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