I am trying to prepare my guitar signal for as best as possible ADC response in order to detect harmonics to the 5th of the highest note of the guitar (1175 Hz for 22 frets), which is about 5875 Hz. This means that I need to be sampling at about 58.75 kHz, which is possible with the microcontroller and it's DSP functions. I am using an STM32F407 Discovery board(https://www.chipsmall.com/Products/STM32F407G-DISC1_10343216.html). So far, I have not come across any solutions that I am happy with. Considerations that are important: *Guitar output impedance: about 1M ohm.[br] *Anti-aliasing for the ADC[br] *Guitar signal of 500mV Vp-p max[br] *ADC input range 0-3.3V[br] *5V single supply[br] *Frequency range from 82Hz and 5875 Hz Does anyone have any suggestions of a circuit that I can use? I have TL082, LM358 and LM741 opamps available, but I am open to other suggestions. The goal of this element of the projects is to be able to use the first 5 harmonics and a sampled period of the guitar signal for further DSP. This is what I have come up with so far - although I believe it's far from ideal. Any tips would be greatly appreciated.

Hello I want to design a mini radio, as it is one of my homework.. But as I don't quite clearly know about the resonators, I want to ask for your help. I have checked online and found some ceramic resonators, and chose this one: CSBLA400KECE-B0 .(Click the datasheet for your reference: CSBLA400KECE-B0.pdf ) Now can anyone ansewer me the following questions: 1.What are the advantages and disadvantages of this type if I use it in my radio? 2.Some one will use quartz crystal resonators when designing communication equipment, is it OK for me to use ceramic resonator rather than the crystal one? 3.Do you have any other choice of the resonator? Any suggestion will be appreciated!Thank you very much !