Home Forums GuitarPCB Build Support D’lay: producing unexpected (and bad) noise effect Reply To: D’lay: producing unexpected (and bad) noise effect

#13407
Billy
Moderator

Once we get your images something might jump out to someone

It’s definitely a strange one which makes it interesting!

I don’t fully understand the internal workings of the PT2399 but I’d imagine with the voltages you have on pin 7 current control 1 and 8 current control 0 it’ll have some strange affect on the output

Hard to find any info but found this from Rob Strand, which is why I said check the op amp voltages thinking it could be a biasing issue

I’ve been told by the manufacturers (and there’s no other way to find this out) that pins 7 and 8 are used to smooth the a biasing supply inside the modulator (MOD) and demodulator (DEM) blocks.

the majority of the PT2399 pins ie op amp ins and outs should be vref supplied by pin 2 so half of whatever’s going into pin 1 from the regulator

I’m assuming you mean R19 with regards to IC1 easy enough to check, with no power to the circuit, remove IC1 from it’s socket and check the resitance between VR and pin 3, I’d use the junction of R17 and 18 as my VR point

Just on a whim I’d visually check your IC sockets too, I’ve had flimsy socket pins bend upwards more than once and cause weird issues