Sunday, 13 April 2014

CultureJam Neptune Delay

Another PT2399 delay from CJ.  An LDR with greater than 1M dark resistance and preferably less than 100K light resistance is recommended.  I put the resistors in between LDR and LED to add a bit of separation so you can get them facing each other more easily.  As usual with these, it's recommended that you tape LED and LDR together or use some heat shrink tubing so you can test the circuit without it needing to be boxed.

Info from CJ about his project

Here is my two cents thrown in to the bucket of PT2399-based delay circuits. It features aggressive low-pass filtering on the delay line to virtually eliminate the nasty artifacts that often plague PT2399 delays; and it also sports a momentary footswitch that modulates the delay time, allowing for some cool pitch-bending sounds and really funky detune effects. It can also be made to sound sort of like a lap steel (in a way).

The base of the circuit is derived from madbean's "Sea Urchin" circuit. Then cranked up the filtering and added the modulation footswitch.


More info can be read in the project PDF posted here.






53 comments:

  1. You guys have done a great job of getting some more delay options available on the site! If you do an analog delay I might just lose it!

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    1. This is highly unlikely, analog delays tend to be very complicated, and often require hard to find BBD chips.

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    2. There is an AquaPuss vero schematic available and verified...but it is big

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    3. I'm thinking it'd be a job for John K if it did happen :)

      I've already got a DM-2 and a Maxon AD-9 Pro so I'm pretty well covered, just think it would be interesting to use an analog delay as a platform for mods/experimentation

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  2. I've actually purchased a PCB from culturejam to make this delay, it is a very very nice sounding basic delay, but what i really dig is the momentary switch that teaks the time function... very cool.

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  3. You can mark this one as verified! This is probably my favorite delay. The time warp is really fun to experiment with.

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    1. Top man! Thanks for verifying

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    2. Matt, do you find that the Delay pot has any effect?

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    3. Unfortunate typo. *Decay* pot.

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  6. Nice delay, the repeats works very clean out of hiss. The "Warp" function is unique.

    I have an issue with the feedback pot. When maxed, i don´t get infinite repeats... i double checked everything....

    Anyone knows that to tweak to get "infinite repeats" or oscillation? This effect is for that purpose :-)

    The best for all,

    Anyone have

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  7. What is the D1 next to 15k resistor and the ldr between ic and 18k

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  8. Built this one tonight. Some very cool tones. I built it with 2 time pots. I don't notice much of a different (if any ) with the Decay knob one way or the other, so I'll keep trying to troubleshoot that.

    I only wish I could get a shorter Time, like a slapback if that's possible from the PT2399. Anyone know which components effect that setting so I can fool with them? Seems like it's got to be that 18k resistor. I didn't have any on hand and I used a 20k. Maybe that's my problem.

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    1. I've been looking over the Neptune v1-3 schematic. I assumed the "Decay" pot would control the regular delay decay, but the decay pot appears to be on the backside of the SW1, so it would only be in the circuit when the SW1 is engaged. Am I missing something? Is Decay just there to control the warping?

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    2. It seems that usually in p2399s people have a 1k instead of 18k at pin 6, before/after the time pot. There's probably less momentary switch compatibility at that short range but I'm about to change it myself.

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    3. Actually, looking at the schematic on FSB and that resistor is supposed to be a 10k anyway.

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  9. Hello, just built this and sounds really great apart from I'm not getting a lot of feedback from the knob, on full sounds like 3-5 repeats maximum, no runaway oscillations :C The only thing I've done different from the schematic is use polymer box caps for the 1u's instead of the polarized electrolytic ones. Could anyone tell me what components to look at for increasing the feedback?

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  10. Hi,
    I maybe say a stupidity, but there is no inversion between FB1 and FB3 on the layout. It should not be the feedback 1 who should go directly to ground ?

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  11. I switched them around too, also can you get yours to go into infinite repeats?

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    1. I haven't built yet, I just received the components. I should build it this weekend or next week. I'll tell you if I have an infinite feedback, if not, I maybe have an idea to have it. I can send you the layout, but I don't try it yet.

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    2. excellent, keep me informed :)

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  12. I finished it today (a little be late, but it's holiday). I have an infinite repeat, but I changed a couple of things for the feedback part, I haven't tried with original layout. I can send you my layout if you want ?

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  13. If its not too much trouble yes please, what things did you change?

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  14. I'll tried to send you with your google+/gmail account.

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    1. Thelonious, what things did you change? could you send me these info too? :D
      giudis78@hotmail.it
      thanks so much

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    2. Arkangelhfb@hotmail.com

      Could you send the newer layout to me aswell?

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    3. If I wanted to adjust this pedal for use with a bass?

      Where should I start?

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    4. This is not the "original method", but just my way to have an infinite repeat,inspired by another delay I made, very close to this one. There are maybe a more simple way to have infinite repeat.
      I changed all the parts in red on the layout (some just because I don't have the original component).
      This is the 6,8k resistor that defined the depth of repeat.
      Works great for me.
      Here the layout, for all who want it : http://zupimages.net/up/14/34/xqt8.jpg

      Here a picture of my pedal: http://zupimages.net/up/14/34/2bw8.jpg

      Thanks to Iviark for all this original layouts ! Always excellent !

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    6. Thank you for your picture. I built this and it sounds good just not really deep delay. I used a GL5549 ldr which is 10M and went with the original layout. I noticed that you are using what looks like ceramic capacitors instead of polyester in a lot of places. I also noticed that you put shrink around the LDR. I am fairly new and was wondering if it matters and also how to determine when to use ceramic and when to use polyester and also poly box. I appreciate your assistance and look forward to your update.

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  15. Hey guys I need some help. I've made one of these, and I trying to test it, but all it is passing is a hiss twobbling sound.

    almost sounds like DCv somehow is in the signal... anyway can someone with a working circuit post the ic voltages so I can compare.

    Thanks in advanced
    ~Ark

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  16. Anyway, in the layout we have to change FB1 and FB3 imo...

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    1. also, decay works much better with a 50kB time pot...repeats will be slower but decay will be very affecting...

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  17. Nice delay! Altough it has a little bit of motorboating at high mix times(used every pt2399 I had to the same result),but i did put a 50K on the time so maybe because of that

    Here is my build

    http://hgecontraptions.blogspot.ro/2014/12/a-culture-jam-neptune-delay-clone-with.html

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  18. Does anyone knows the maximux delay time ? is it > 2 sec ?

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  19. Does anyone know which resistor is responsible for the volume? I think I have a slight decrease in volume.

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    1. I think is the 10k connected with IC6 pin maybe...

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    2. I had this problem too. I got around it by running the circuit into a LPB1 circuit with a trimmer to boost the level back up.

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    3. Substitute that 10k resistor with a 50k pot and you'll get a volume control... :D

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  20. thanks for this schematic and all the work that you have put into the blog.
    I'm thinking of powering this pedal with an old nokia charger . what mods should i do to the schematic ?

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  21. Can I use momentary DPDT to control the decay? How can i do it? Thanks.

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  22. I built this and sounds awesome. Thank for the layout.
    https://www.youtube.com/watch?v=vCMWtmD4RdY

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  23. Does anyone know how to omit switch? I don't need momentary switch on pedal so how to remove it from circuit?

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  24. You could simply omit the switch and the wires that connect to it.

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    1. OK. That means just don't connect it? Thank you for your answer.

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  25. Does anyone have the project pdf? The link is dead.

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    1. Schematic is here:
      http://www.freestompboxes.org/viewtopic.php?f=72&t=17216
      You might have to be a member (register) to see it.
      I usually just go to Freestompboxes.org to find schematics for almost all of the projects here that aren't otherwise listed.
      Good Luck,
      Will

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