bkshepherd
commented
10 months ago After much investigation, the issue is that the new audio Codec chip in the Rev 7 daisy seed (the PCM3060) does not include a very strong on board Low pass filter on the audio outs compared to the audio code used prior to Rev 7. According to the spec sheet on the PCM 3060 "An external low-pass filter is used if further out-of-band noise rejection is required." Sure enough, if I add a low pass filter to the audio outputs, the noise issue is resolved. This will be included in the next revision of the pedal design as shown in the attached schematic:
There is an issue causing noise in the signal when there is one of my pedals using a Rev7 Daisy Seed has another one of my pedals connected to the output of the first pedal. It doesn't matter which rev Daisy Seed is in the second pedal, the noise will occur.
This issue does not occur when using multiple of my pedals with Rev 5 Daisy Seeds in each of them back to back. This issue does not occur when there is only a single one of my pedals in the signal chain.
Working with Electro-Smith to identify and resolve the issue. No further information at this time.