Daisy Seed + Terrarium Rev5 -> Rev7 terrible SNR

Hey everyone. I built a terrarium pcb clone for a pedal last year with daisy seed rev5. I was able to flash software and run the effect successfully on the platform without issue. Since then, I have revisited the project and am attempting to get it to run on Daisy Seed Rev7.

When I went to test the pedal with my new seed, the same software was running with an incredible amount of noise. Here are two examples of daisy seed rev5 vs rev7 flashed with input routed to output.

This seems like really very very bad… perhaps there is something we are not accounting for with the new revision… Does anyone have a solution to this or is this just the codecs performance?

as a note: the input to this is from an audio interface ~10dbFS below full output (not a guitar level signal)

rev7:
rev5:

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Hi,

  1. how do you do the power supply to the terrarium and do you cut the USB connection to the PC when playing?
  2. What kind of noise are we speaking of? I can hear some overdrive noise in your post. Do you mean that kind of noise?
    What amplitude in mVpp is “~10dBFS” ? Did you use exactly the same level?
  3. Is this an exact clone of Terrarium, same parts and schematic?

One significant difference between Rev5 and Rev7 is in my opinion, that the codec of Rev7 is running at 4.5V and if it’s supply comes from USB then Daisy’s regulator has very low voltage difference to operate, so an additional 9V battery (6*AAA) can make a difference. But this in my case was about background noise. ( Rev 7 noise floor vs Rev 4 - Troubleshooting and Support - Daisy Forums (electro-smith.com) )

YES I am getting the same type of noise on the daisy seed 1.2 rev 7. I used an old terrarium build that I had confirmed to work with the rev 5 (very low/acceptable noise) and I plugged in the new daisy seed and got a terrible noise. I also tried isolating the TL072 buffer and with a clean signal it worked fine, but something about the output of the new Daisy makes it the Terrarium circuit go haywire with the noise.

I took the same Daisy seed and plugged it into bkshepherd’s open source pedal project, and it works fine! I’ll have to look at the differences in those circuits.

I’m very interested in getting this resolved somehow, I have quite a few completed terrarium builds that don’t have daisy seeds installed yet. If there’s no way to get the old version of daisy seeds I’m afraid those builds may have been a waste of time and money…

Here is a video of what I’m getting with the terrarium and the daisy seed 1.2 rev 7. (Again, confirmed to have worked without noise with the rev 5)

Adding a LP filter fixed the noise issue for me:

Added a 3.3k resistor and 2.2nF cap for 22khz low pass filter, as shown in diagram below, courtesy of @kshep

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