The best one I can find is on the shop page. Zooming in it’s just possible to read the values.
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Thanks Sonosus!! It helped me to figure out the placement of all the components of the schematic. Even though all connections seem fine when measuring with a multimeter, and I reflowed all solder connections, it still does not work. This got me thinking whether one or more of my chips are faulty. After some internet searches, I am wondering whether one of my PT2399 chips is a fake! This site shows a fake on the left, and the official chip on the right: PT2399 : False and genuine - H&G Amplifiers One of my chips has the exact same housing and lettering as the fake chip on the left of the picture shown on the linked webpage.
I think I will go to my local electeonics store where I bought the chips, and ask for some replacements.
Stefan
2 Likes
my first stripboard layout ever, made from Kosmo schematic.
I thought it would be much more difficult… i did it in one day
a bit messy but is on 1 single board.
still untested and unverified…
Before starting to build it i have to build another module (a triple lfo) so anybody is welcome meanwhile to take a look for mistakes 
i can share my DIYLC file in case somebody wants to modify, improve or whatever 
i hope i marked correctly the leds
d5 is the led of the CV which affect the TIME 1 (big knob), right?
ps. i noticed the recent post about fake chips…
i have a pt2399 which is called HLF …should it be ok?
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Hi,
I am having trouble making the 2399 Delay working. I do not get any delay effect. For troubleshooting, would it be possible to test each of the stages separately, to figure out where the problem is located? For instance, can I hook up Out 1 of the first 2399 to pin 6 out the op-amp, as according to the schematic pin 6 is normally connected to Out 3?
Thanks in advance!
Stefan
the first thing would be to see if it sounds different at all between sound and bypass.
the fact that it is making sound suggest it works. if it sounds softer that might suggest its working too.
maybe check around the voltage of the time knob.
look at theboard very hard make sure all capacitors are soldered well, wiggle them if you have to. ones that are not properly soldered down the solder joint on the otherside will wiggle
Thanks for these suggestions! I already reflowed all solder joints, including all the capacitors. I checked all connections in accordance with the schematic with a multimeter, and all seemed fine.
(BTW: It seems as though the numbering of R37 and R39 is switched between the schematic and the PCB. Both are 100KOhm, so no problem, but it made finding the path more difficult. 
)
The module is passing through sound in bypass mode. When turned on, the sound level goes down quite a lot, and I am not hearing any echo/delay effect. And no matter how I twist the knobs, I am not getting garbage mode.
I left out capacitor C22, as I would like a delay that can be handled, as suggested on the project page. Just to be sure: nothing should be in the place of C22, no wire or something, right? Also, I was not able to find C22 on the schematic; am I missing something?
Thanks for letting me pick your brain!
Stefan
Good to mention: After I reflowed all solder joints, I reinstalled all chips, and hooked it up for a late night test. This was my first time seeing flames from the back of a module, with the 10R resistors I had in the FB1 and FB2 positions going up in flames!
Yesterday I found the reason why: I was so sleepy the night before, I placed the TL074 op-amp 180 degrees in the wrong direction…
So yesterday I replaced the 10R resistors and the op-amp.
I have a rule: Never work on a new module after 10 pm.
6 Likes
You are absolutely right, I should have waited for the next day to do some tests with a clear head.
Before starting with some new tests, I have one question on the module. When should the LED on the top left corner turn on? Mine is not doing anything, no matter the position of the pots. What does that LED indicate? Maybe this could be a clue as to why my module does not seem to work?
Stefan
that wull only turn on when really loud signal is coming out. its tough. the description you have done can mean a lot of things.
the fact you are hearing sound im not sure. maybe its about listenning to parts of the circuit. setup a listenning probe basically ground connected then a wire plopping about, listen to the points before the first delay circuit, see if thats working then after first delay circuit etc. looking at schematic, work out at which poiunt its not working
i suspect first delay coircuiot but who knows! check it oot. good luck
2 Likes
As suggested, I made a listening probe, and did some tests. I get a strong signal between C30 and R26. But on the other side of R26, as well as at the connected R7, R8 and C34, the signal is very, very low. I switched the PT2399 around to see if it could ve the cause, as R7 and R8 are connected to pins 15 and 16 of the first PT2399 chip U1, but that made no difference.
Any ideas as to what could cause this are appreciated! Maybe C34 is not working properly?
I guess to see if its just the first stage get a wire or crocodile from working side of C30 and wire to pin 15 of first pt2399 without the pt2399 in it. If its all working fine and dandy, issue is in the first circuit somewhere. If its not working, then its worth looking fu4ther afield. At the ref voltage and voltage control circuit
I choose ur work to be the first unverified layout i’m gonna (try to) verify
Gonna take a few weekends unfortunately ^^’
U still got those DIYLC-files flyin’ round??
Hi,
unfortunatly i didn’t try to build it yet… i moved to a new house and i’ll be back on tracks not soon with those things… give your email and ill send the file, i don’t know how to attach it here
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I’ve tried to build the simple stripboard version and didn’t get it to work yet (input is played back on the output with no noticeable effect), is there a simpler way than debugging the entire circuit to verify whether my chips are authentic? I’ll try looking at the output of pin 5 see what it does.
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Hey, i have built 3 of the PT2399 delay (including the triplesplash one). I tested 3 batches of chip as well. They all worked, with fairly different performance, but i got some delay signal on each of them. The mistakes i made twice was to use a wrong capacitor size (nf instead of pf) and it goes from doing nothing to working just fine.
Yeah, and it looks like measuring the resistance between pins is a good way to verify the chip is at least not a complete impostor… though mine don’t measure the announced numbers
I never have any luck with stripboard, i’ll see if i can salvage it, i want to at least confirm my chips work! I have a batch of SOIC chips in the mail too, but as usual, from an Ali vendor you should never ask where they come from.
I wanna experiment with the chip, but i’m gonna take a simpler route than stripboard for the future experiments haha:
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If you mostly want to test the chip for now, what about getting some PCB circuit already made ? There are plenty of options for this kind of cheap echo circuit, some come already assembled as well.
I’d have grabbed one of those Aliexpress red karaoke boards, but none have a chip holder so it seemed like a pain, haha.
I still haven’t managed to find the issue with my stripboard, but either way, this bad boy is about to be sent to the factory (i’ll probably give it a proper thread rather than hijack this one when they arrive) 
4 Likes
Back to tinkering today. Tried to swap all the transistors out for new ones, something told me that if it shorted out originally it might have taken some transistors out. No luck on the delay but the LED`s seem more frequent than they ever have been. CV Stoll makes it go nuts in the light show department but sadly no delay. Just makes the sound ever so slightly warmer…
Honestly im probably just gonna go find a cave to play in XD