I’m working on a prototype for a desktop multi-tap delay effects unit. I’m still a beginner with working with hardware and I have been following the schematic for the Daisy Field for the general circuit structure on a breadboard. However, I’m wondering about the inputs and their related buffers. To hook up a guitar I would need an amplifier in the circuit right? I have a selection of op-amps available (TL072, MCP 6002 & NE5532). I’ve seen several designs utilizing the TL072, but it not being rail-to-rail confuses me with integrating in a Daisy based system. I’m looking for recommendations on resources on the topic and all help is appreciated!
Hi,
Opamp for input buffer selection: TL072 is the workhorse and will work fine with as low as a single supply 5V (the simplest case to integrate with the Daisy from single power supply) but in a unity gain follower it may introduce some noise for the audiophiles in the crowd. rail to rail should not be an issue from guitar pickup level to instrument level (I believe) but if you plan to use it with a tubescreamer in front you may hit the rails (dont think this will damage the Daisy) NE5532 is top notch for low noise but requires higher voltage and has lower input impedance (may load guita pickups) . MCP is rail to rail, low voltage low power but has limited slew rate and higher noise.
stick with the TL072.
If you want to push it some more - I am currently aiming for the OPA1688IDR as an input buffer and also as a headphone driver to reduce IC type count.