gtfields13
Well-known member
Just dropping an observation from my latest build so anyone looking for this might find.
I made a pair of Seabed Delay (Mad Professor Deep Blue Delay) PCBs, and I used a Princeton Tech PT2399 in one, and LingxingIC PT2399 that I bought from LCSC to test. I was having issues with the LX chip latching, and found a good explanation of this chip on Electrosmash (PTC 2399 Analysis).
Reading the ElectroSmash site, the Analog Ground and Digital Ground are supposed to be connected, but in the Seabed Delay PCB's schematic they aren't - I think the Digital Ground might just be floating (i.e. no connection). So I jumpered pin 3 and pin 4 on the IC, and this has solved my latch-up problems for the lower cost chip.
I went back to checking the noise from both chips and with input grounded, the PTC version of the chip definitely has a clock tick audible when the gain is turned up (2.5x my usual setting), but the non-brand Lingxing chip has no audible noise - definitely no clock tick. So the bargain chip actually seems preferable to me in this pedal.
I made a pair of Seabed Delay (Mad Professor Deep Blue Delay) PCBs, and I used a Princeton Tech PT2399 in one, and LingxingIC PT2399 that I bought from LCSC to test. I was having issues with the LX chip latching, and found a good explanation of this chip on Electrosmash (PTC 2399 Analysis).
Reading the ElectroSmash site, the Analog Ground and Digital Ground are supposed to be connected, but in the Seabed Delay PCB's schematic they aren't - I think the Digital Ground might just be floating (i.e. no connection). So I jumpered pin 3 and pin 4 on the IC, and this has solved my latch-up problems for the lower cost chip.
I went back to checking the noise from both chips and with input grounded, the PTC version of the chip definitely has a clock tick audible when the gain is turned up (2.5x my usual setting), but the non-brand Lingxing chip has no audible noise - definitely no clock tick. So the bargain chip actually seems preferable to me in this pedal.