Recent content by n9ds

Update: The buzzing wasn't due to the 220Ohms. I replaced it with 0 Ohms and had the same problem. I tracked it down to the power supply. It was one of those switch mode wall warts. Even a more expensive "ultra quiet audiophile" one had the same issue (both work fine with the other guitar...

Finally some progress. Thank you for all your suggestions, I have made a number of changes. Rewired so that the muted output gets sent to a sink instead of into the ether Added a destination for the Aux/Tuner output All four LED anodes are now controlled directly by individual pins and not...

Yes, muting isn't optimal. I'll worry about that later. I'm using a relay to switch LEDs because it requires fewer pins. I built an outboard regulator with a different 7805 with capacitors (2 220uF and 2 .05pf because that's what I had on hand...) I connected the output of that across 1 and...

You first sentence is completely correct. The "Mute" works by sending the audio signal into the ether. I did add 22uF between the + and - rails that is not on the schematic. At one point I had added another small value (.01uF maybe?) in parallel with the 22uF, but that didn't solve the...

I fixed the extra wire on K3, thank you. It was in the schematic but not the board. My mistake, not J4, it's J2. As far as J5 is concerned, the red anodes of the LEDs (there are 2 bicolor LEDs) are connected to pin 4. The cathode of LED 1 is connected to pin 3 and the cathode of LED 2 is...

1) The pin toggles continuously every 500mS. I only see the spikes when the pin transitions from low to high or high to low. To make the spikes go away, I keep the pin high or low. (To be over-specific, when it switches from "mute" to "live", B.5 goes low and B.4 goes high. Both stay there...

Below is my schematic. The idea is to route low-level audio with the relays. When in mute mode, I've programmed B.5 to toggle every 500ms. The problem is that is introducing a small (4-5mV) spike in the audio path (the first image is the scope trace.) The audio is microphone level, so 4mV is...