I tried 12 different 2399's, one was bad. When it works, it is AMAZING.totally in love with it.īut it locks up on every power up, despite the "fix".i read rick's thread on DIYstompboxes, and tried merlin b's fixes, changed the 68k resistor to 220k (which helped a little) and even tried lifting the 47r resisor and replacing it with an led from e of the 3904.no dice at all on that one. I built your layout of number 4, it's working, but i swear to god it's on an overdose of LSD or special k or something. Ijust want to fix this little imperfection if possible. I would just use that mode but I like the slightly darker tone of the normal mode. The only other thing worth mentioning is that the slapback sound doesn't happen in the vibe mode. I haven't swapped out the pt2399 chip yet ( I have read all the comments here and elsewhere about the inconsistency of these so I ordered several extras ) but will depending on what I hear back from here. I don't want to unsolder and replace if these are not the cause. I used them anyway since they weren't grossly off, but I wonder if these components may account for the slapback because of where they are in the circuit. Is this normal for this unit? Anyone else experience this? I tested all the components before soldering and there were two components that were a little off - the 1n cap measured 1.26nf ( I measured all 20 that I had ordered and they were all off the very same amount ), and the 220k resistors were right around 200k each. It almost has that "pop" too of a compressor ( I think that is just the delay fooling me ). I really only notice it when I play a string of single notes - it's fast enough so that I don't really notice it too bad when I am playing an arpeggio. It happens regardless of speed or depth setting. Kind of like if you have the regen knob turned past the middle point on a delay pedal so that you hear the delayed note louder than and behind the note you just played ( except that you don't hear the first note - its all just a little behind what you've just played ). When I play through it with neither the s/w nor c/v switch engaged, it sounds almost like a slapback delay. The most complicated effect I've built so far so I have to say I was actually a little surprised when it worked as I fired it up for the first time! Just wanted your thoughts on one aspect though. This is the first time that something i've built started to act up later than on the building phase. I'll try another chip and we'll see how it goes. Does that space-sitar description sound like that locking issue the earlier revisions had? I'm pretty sure there is just something fairly simple i've missed. I'll get some sleep, go to work and figure this out after that tomorrow. My best guess is that whatever burnt the regulator might have done some damage to the PT2399 as well. Suddenly it started to sound really crazy. But that's like using bigger fuses to prevent them from tripping.Īre there any simple solutions to protect regulators? I could swap the regulator for 7805, which is rated 1A. I guess it seems like i have some ground leak in there somewhere. But i don't thing that in normal circumstances PT2399 could ever draw more than that 100mA. Best not use that adapter with these regulators i guess. Swapped it for a fresh one again and it worked. Everything worked like a charm again.Ĭouldn't believe that the adapter had burnt the regulator, so i tried with the wall adapter again - it burned the regulator right away. Swapped it for a new one and switched that wall wart for a battery. Which shouldn't be enough to burn the regulator. Measured the wall wart, and it says 9,3V. Checked basic stuff out, and noticed that the regulator gave out only 1,2V. Plus the vibe/chorus switch was mute on the other position. I sticked my cheapo wall wart to it, and it sounded strange. Started to play with mine today just for fun. It would be easy enough to change it back if necessary, or even add an additional gain stage and maybe an overall volume control, but that would mean a bigger layout or a small addon daughterboard of some description. These haven't been tested and I don't know how they might affect the output volume but they're definitely worth a try. Or if you wanted the dry signal always present (the Chorus/Vibe switch will still be able to remove it completely if you want) then you could go this way instead:īlend 2 would go to the output, Blend 1 to ground. So the pot will blend between the modulated PT2399 output and the dry signal coming from the NE5532. With an additional cut between the new cap's leads. To add a mix/blend pot, you'd need to remove the 100n cap at the output (the smaller one below the 10u cap) and add another below the other 100n output cap underneath IC2.
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