Terrarium Rev 1 with Daisy Seed v1.2 rev 7 Noise Issue Work Around - Applies to OLD Terrarium REV 1 board only!

[keyth72]

Hey all, I was curious if anyone has built a Terrarium recently with the latest Daisy Seed v1.2 rev 7, I am getting horrible noise with it. I used a previous version of the Daisy Seed with the same Terrarium and it worked fine.

Here is an electrosmith forum tracking the issue, along with sound examples:

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...

forum.electro-smith.com

 

[Paradox916]

Hey all, I was curious if anyone has built a Terrarium recently with the latest Daisy Seed v1.2 rev 7, I am getting horrible noise with it. I used a previous version of the Daisy Seed with the same Terrarium and it worked fine.

Here is an electrosmith forum tracking the issue, along with sound examples:

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...

forum.electro-smith.com

Is that software revision or hardware? That’s pretty noisy

 

[keyth72]

Is that software revision or hardware? That’s pretty noisy

Hardware, I believe they had to use a different audio codec because the old one became unavailable. I got a tip to try adding a low pass filter to the output of the daisy seed, prior to the output buffer, so I’ll see if that helps and report back.

 

[Paradox916]

Hardware, I believe they had to use a different audio codec because the old one became unavailable. I got a tip to try adding a low pass filter to the output of the daisy seed, prior to the output buffer, so I’ll see if that helps and report back.

…. That sucks. LPF in the code or a physical LPF circuit?

 

[keyth72]

…. That sucks. LPF in the code or a physical LPF circuit?

Physical, this is what I’ll try:

 

[keyth72]

Physical, this is what I’ll try:
View attachment 73450

This fixed it, low pass filter right after the audio output of the daisy seed. Used 3.3k resistor and 2.2nF cap for a 22kHz low pass, as shown in the diagram.

@Robert I recommend (after verifying with your own test) a revision to the Terrarium to include this LP filter for use with the Daisy Seed v1.2 rev7. Might want to reach out to Electrosmith to verify this is the configuration they plan on using going forward. I’ll be making this change to my own custom boards that use the Daisy seed.

If anyone else tries this please share results! More data points would be great!

Edit: if anyone can explain why this works that would be awesome, clearly the noise isn’t above 22khz or it would be inaudible, so I’m guessing something else is happening in the LP filter circuit/daisy seed output that makes it happy.

Here is the “before” noise I shared in the Electrosmith forum:

 

[Aentons]

I have a v1.2 rev7 board. I built the terrarium on a breadboard and I got that same noise. I already reused the breadboard since I ordered a Terrarium but haven't soldered it up yet.

 

[RobinMallard]

Thanks for the tip! My Terrarium is still in progress, so perhaps I’ll try adding this in the vicinity of C2 and R9

 

[kylewetton]

Not to throw a spanner in the works here but my Rev 7 is clear as a bell without the filter. It’s likely worth building it anyway for those that haven’t put theirs together yet

 

[Aentons]

Not to throw a spanner in the works here but my Rev 7 is clear as a bell without the filter. It’s likely worth building it anyway for those that haven’t put theirs together yet

That's interesting. Is yours the one soldered into the sockets? I wonder if the sockets have a tiny bit of resistance/capacitance that makes a difference.

 

[keyth72]

Not to throw a spanner in the works here but my Rev 7 is clear as a bell without the filter. It’s likely worth building it anyway for those that haven’t put theirs together yet

Interesting! Thats why I want more data, and you’re using a per build docs Terrarium? Using a TL072 output buffer

To clarify, if I connect directly to the Daisy Seed audio output pin (line level) it sounds fine, no noise. It's only when I use it with the Terrarium's output buffer circuit. The exact same Daisy Seed sounds fine with no noise in another pedal I have that uses a different op amp output buffer (this working circuit matches the now discontinued Daisy Petal from Electrosmith). So my guess is it's related to something specific to the Terrarium's output buffer. But if you're using the same configuration with no noise.. who knows

 

[kylewetton]

That's interesting. Is yours the one soldered into the sockets? I wonder if the sockets have a tiny bit of resistance/capacitance that makes a difference.

Yes it’s soldered, I have another one in the mail, I’ll test

Also to both you and @keyth72, I’ve only tried it into a USB interface and no amp model, I’ll run it into my Orange today and let you know what happens

 

[Spiff4565]

This is interesting. I was thinking about building one of these. Now I'm not so sure. May have to wait until the issue is identified and/or resolved.

 

[FuzzyLotus]

Heyoooo - I have finished building this with a rev7 - not getting noise at all and it's not even boxed up yet - super clean.
My seed is on sockets - everything good.

 

[Aentons]

Heyoooo - I have finished building this with a rev7 - not getting noise at all and it's not even boxed up yet - super clean.
My seed is on sockets - everything good.

Do you have an effect loaded or just the test program? Are you using machine pin or leaf spring sockets?

 

[cbg342]

Just wanted to say I've just experienced the same thing. Built the terrarium with rev7, thought wow that's noisy. Plugged in my rev5 and it's much more clear. I'll try the RC filter trick soon but I wonder why others in this thread are saying rev7 works for them.

 

[keyth72]

Just wanted to say I've just experienced the same thing. Built the terrarium with rev7, thought wow that's noisy. Plugged in my rev5 and it's much more clear. I'll try the RC filter trick soon but I wonder why others in this thread are saying rev7 works for them.

Thanks for sharing the info, yeah it’s very strange, some people get it and some don’t. For sure let us know if the filter works for you! I’ve posted on the Electrosmith forums and discord but haven’t heard an official response from them on what’s going on, just relying on user data.

 

[FuzzyLotus]

Do you have an effect loaded or just the test program? Are you using machine pin or leaf spring sockets?

I have an effect loaded - loaded it from plugdata.

Not too sure what machine pin or leaf sockets are,
This is what I have used:

20 Pin 2.54mm Single Row Female Pin Header

GTK - Get It Fast - Same Day Shipping

www.taydaelectronics.com

Edit: I'm actually building three of those pedals this week so I'm going to report back and let you guys know if there is any noise in them as well.

 

[FuzzyLotus]

Update: my three boards actually all make a noise, i was mistaken. Just that my amp was no loud enough for me to recognize the sound.
Now i gotta add that filter. How do i go about adding this to my already soldered builds? I'm kinda crap at analysing circuits lol

 

[keyth72]

Update: my three boards actually all make a noise, i was mistaken. Just that my amp was no loud enough for me to recognize the sound.
Now i gotta add that filter. How do i go about adding this to my already soldered builds? I'm kinda crap at analysing circuits lol

Oh no! So what I’ve been doing, and this is not a perfect solution, but I rip out the U2 capacitor and carefully clean out the solder holes if you can, and put some wires in there, connect that to a little board that has the replacement U2 cap, and the low pass filter containing the extra cap and resistor. I also have a wire from this connected to ground, usually the output jack ground lug. Clear as mud?

Here’s a pic of one of the stand off board with the filter and U2 cap:

And an update, after some talking on the Electrosmith discord, it seems like this low pass filter has less to do with an actual audio filter (as it’s higher than audible hearing at 22kHz) and more to do with putting a load on the new codec chip in a way that makes it happy.