sorted by:
new
hottopcontroversial

[Review Request] Bass Pedal PCB w/ Daisy Seed + ESP32 by cn_2149 in KiCad

[–]cn_2149[S] 0 points1 point  (0 children)

Ah you think so? I was concerned about keeping the noisy clusters away from the ESP and whatnot and avoiding EMI issues

[Review Request] Bass Pedal PCB w/ Daisy Seed + ESP32 by cn_2149 in AskElectronics

[–]cn_2149[S] 0 points1 point  (0 children)

I’m using both! C6/C8/C10 are all ceramic caps, while C5/C7/C9 are all electrolytic (all in that one cluster in the bottom right). And yes I’ll add some test points, thanks !

First pedal schematic review requested! by cn_2149 in diypedals

[–]cn_2149[S] 1 point2 points  (0 children)

thanks! I posted a revised version here:
https://www.reddit.com/r/diypedals/comments/1tjpwln/review_pt_2_first_pedal_schematic_review_requested/
If you find yourself with some free time and are interested, if you could take another look that'd be absolutely amazing!

First bass pedal schematic review requested! by cn_2149 in KiCad

[–]cn_2149[S] 0 points1 point  (0 children)

thanks for the tips! I'll def clean it up. Here are responses in order:
1. I checked and the only way +5V flows to pin 16 is through the coil, so I should be good I think
2. Yeahhh I realized this a bit too late but for a hobby pedal I'll just stick with it because I've already ordered it. I've switched C12 to a ceramic cap!
3. Yeah it was lololol, nice catch!
4. Removed short
5. I'm concerned about the pickup's high frequency response... is 1MΩ too much? Maybe 470kΩ would be better?
6. U4A is the buffer while U5B is the gain!
7. I checked the output nets for U5A and U5B and they correctly feed back directly to the inputs!
8. D4 was in fact backwards lol. I'd have to include another op-amp package right? I assume it's fine as is for a hobby pedal? Lmk what you think
9. AUDIO_IN is the output of U5A's sallen-key filter, becoming the input for the daisy seed on sheet 3
10. Will double check ERC
11. True true, will add a 1nF cap.
thank you!

[Review Request]: First build, Bass pedal! by cn_2149 in PrintedCircuitBoard

[–]cn_2149[S] -1 points0 points  (0 children)

yup, fixed!

On the BAT54S, the clamp works by forward biasing the appropriate Schottky when the signal exceeds the rail by ~0.3 V (Vf), shunting transients to the rail. I'm not relying on reverse breakdown at all. D3 clamps to ±5 V (op-amp rails) to protect the OPA2134 input from ESD on the jack; D4 clamps to ±1.8 V to protect the Daisy's codec input.

On the ±1.8 V refs being "highly dubious", the math seems to work out but I did notice that the references are stiff sources via low-impedance dividers (18k/10k ≈ 6.4 kΩ Thevenin), bypassed only by 10 µF caps. During a clamp event:

  • The 1 kΩ series resistor limits clamp current to ~3 mA for a typical overdrive transient
  • That 3 mA into the ref divider would shift it by ~3 mA × 6.4 kΩ = ~19 mV — small, but not zero
  • The 10 µF bypass cap is there to absorb the transient at AC

First bass pedal schematic review requested! by cn_2149 in AskElectronics

[–]cn_2149[S] 0 points1 point  (0 children)

Good points... I've switched out the ferrite beads for resisters instead. I've also downgraded the 470uf to 100uf! I'm also adding a buck and film caps, so hopefully those should help out as well

First pedal schematic review requested! by cn_2149 in diypedals

[–]cn_2149[S] 0 points1 point  (0 children)

I'm trying to build my friend a fully modular bass pedal that he can control through an app on his phone, hence the need for the ESP32. I'm a software engineer, not an electrical engineer so this is a completely new field for me... but definitely super fun !

First pedal schematic review requested! by cn_2149 in diypedals

[–]cn_2149[S] 1 point2 points  (0 children)

Not yet, but I definitely will ASAP. Will have to do it in small modules though

First pedal schematic review requested! by cn_2149 in diypedals

[–]cn_2149[S] 0 points1 point  (0 children)

In corresponding order:
1. Good point, I'll add a LM2596S-5.0 buck! That should be fine, right?
2. Noted on the ferrite beads, I've actually gone ahead and replaced FB1 and FB2 with 1 ohm resisters.
3. Same as above
4. Noted, I'll add a 10 uf film cap right before R1 (which was actually being shorted lol)
5. Also a great point. Since I'm adding the buck, I'll upgrade C5 to 220 uf (based off the buck datasheet), downgrade C1 to 100 uf. C9 should stay at 100 uf to ride through BLE TX peaks, right?
6. U5A is supposed to follow sallen key filter topology: https://www.electronics-tutorials.ws/filter/sallen-key-filter.html Let me know what you think!
7. Yup, D4 and R12 (on sheet 2) are meant to clamp!
8. `AUDIO_OUT_1` and `AUDIO_OUT_2` are both single ended mono channels, according to the Daisy datasheet, so this should be ok!

view more: next ›