Request for help - Fuzz AC power noise

[keevon]

Hello!

I recently built a silicon Tonebender MkII circuit: http://tagboardeffects.blogspot.com/2013/07/npn-si-tonebender-mkii.html Transistors are three 2N2369's measuring 60-70 hFE.  The only changes I made to the circuit were to the diode (1N4002 instead of 1N5817) and a 10K linear bias pot instead of the 5.6k resistor on Q3.  For the offboard wiring I used this layout: http://tagboardeffects.blogspot.com/2012/02/offboard-wiring.html

The fuzz works beautifully, but I'm getting a lot of background noise when it's plugged into AC adapters.  My single cord adapter yields a consistent hum, while my cheap daisy chain adapter creates a siren sound.  The siren noise increases frequency when I connect other pedals to the daisy chain.  It gets louder with more volume and gain (naturally).  Changing the bias doesn't affect the noise. 

Here's a clip of the siren noise: https://www.aronnelson.com/DIYFiles/up/2021_06_21_10_34_52.mp3

Below are a few pics of the build for reference.  My wiring connections appear to be OK (albeit messy) and I don't have any solder bridges on the vero board.  When I disconnect the power cord and run it off a battery, the background noise goes away.

Since I'm new to this, I'm not sure how to start troubleshooting.  Are there specific issues that I should look for, or possibly mods to the circuit that will fix the noise issue?  Any help would be greatly appreciated.

Thanks!

[duck_arse]

without a circuit diagram ..... I'd say easiest thing to try is to lift the K end of D1 from the board and solder a resistor - 100R ~ 470R - from the K to the hole it vacated. this will form an RC supply filter, might knock out some hash.

[keevon]

Thanks!  To confirm, you're talking about this end of the diode, right?

[duck_arse]

ahh yes sir, 100% that is exactly what I am talking aboot. consider this confirmation.