Sunday 11 September 2016

King Dubby Delay

Here's a really nice delay designed by Nocentelli.
You can find the original thread on FSB here.

This is his description of the circuit:
Here's a variation on the deep blue delay; two PT2399 chips and a current mirror delay pot give around 2200ms delay, although beyond 700ms gets pretty lo-fi. There are two points where a momentary SPST can be used: Either to briefly connect the input to the delay input on select phrases (dub mode), or to bypass the repeats feedback resistor for self-oscillation on demand.


42 comments:

  1. Nocentelli's demo for this is totally badass. I'd build it right now if I had any big stripboard pieces left.

    Great layout as usual, and really cool design from nocentelli.

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  2. Great layout! I may have to try building this again. As it's drawn, there will be no repeats unless you hold down the "dub" momentary switch, so it's probably worth adding a toggle switch to short the lugs when you don't want dub mode. I used a single momentary footswitch and a DPDT toggle to switch between dub mode or oscillation mode: There's a wiring diagram for this here -

    http://i80.photobucket.com/albums/j190/Leeroyfunk/dubby%20footswitch_zpsscycspeh.gif

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    1. Thanks for the help and the project!
      I've updated the layout:
      Is that what you meant?
      You use 2 Momentary and one DPDT?

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    2. No, I just use one single momentary and one toggle that assigns it to either dub OR oscillation (see the picture I've linked to). I couldn't envisage wanting to use both at one, or being able to hold down two foot switches simultaneously without toppling over. I would advise that if someone wanted two momentary footswitches with one for each effect, they'd just need a SPST toggle to short the lugs of the dub footswitch for constant repeats.

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    3. Ok, thanks.
      It should be correct now.

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    4. That looks right: I'm just a bit puzzled by "Switch 3 - 2&4-> Dub Sw1"

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    5. That was a left over from previous layout.
      I've removed it.

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    6. Hey, I'm still having trouble understanding this wiring for one momentary with a DPDT to choose between Dub or Oscillation. I see the photobucket link, but maybe the naming scheme is what's confusing me. On the drawing, it has Dub1, Dub2, and Osc2 coming off of the DPDT, where do they connect to if in the picture of the layout the DPDT is the Dub switch?

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  4. I built this one on an etched PCB:
    http://effectslayouts.blogspot.com/2015/09/king-dubby-delay.html

    Works mostly... Now that I see this layout posted, I'll have to poke around some more and see if I can get it fully working. Thanks for this layout!

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    1. And thanks nocentelli for linking us to that photo.

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    2. I was able to accomplish all that I wanted, which was to have a regular bypass, with momentary Dub Switch and momentary OSC switch. I wired it exactly as nocentelli mentioned with the addition of a simple slam mod on the OSC switch. On the OSC momentary switch, I soldered two sockets (one on each pole). I put a 20k resistor on there for starters. Then I ran a wire from one pole of the momentary switch to lug 2 of the Repeats pot, and another wire from the other pole to lug 3 of the Repeats pot.

      It was a lot of trial and error, but I finally figured it out. Hopefully someone will find this info useful.

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  5. This concept of dub/ osc, if being applied to the Sagan Delay would result in the DDD! Definitive Dub Device. We need a brave one that makes the scheme for that. After that, add the Dub Siren to this monster, and you ll have big party!-)

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    1. Do you mean a schematic or a layout?
      There is a verified one here:
      http://tagboardeffects.blogspot.fr/2015/10/sagan-delay.html

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  6. yes! I noticed that, a great job by the way, I was joking about the fact that mixing these 3 blocks would be awesome for a reggae sound, I bought the pcb for the Sagan Delay, I am a coward, I know, facing big veros I find it a little dangerous for me. The fact is that I remember asking Chris (SaganDelay creator) about the chance to add the nocentelli momentary dub oscillation to the Sagan and he told me a way, but finally I didnt mod this, but seeing the king dubby again, really would be a great addition. I have to try and then I' tell you about. When Ill have it done, Ill comment in the forum or at at the Sagan Delay itself. In fact it was really simple, We add a DPDT for selecting SlAM pads with 2 of the outer lugs, and with the other 2 outer lugs, R24, the 10k that comes from 1uf must be cut and one outer lug from DPDT goes there and the other lug to the point where it would join 5k1, 10k , 10k and 4n7. Middle 2 lugs of the DPDT would be used for the momentary. That was the explanation, I hope this to be of some use. Thanks for the amazing layouts!

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  7. Can someone verify this pedal?

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    1. Hi Svein!
      Have you tried to build it?

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    2. No not yet. I was wondering if someone else has build it yet. I'm looking for a next project, but last time I didn't have much luck with an unverified layout

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  8. I'm still having trouble getting this one to work. I think I may be confused with some of the switch wiring.

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    1. There is a regular 3PDT Bypass footswitch.
      A "DUB On-DUB Off" DPDT toggle switch (On/On) with lugs numbered the usual way:
      1 4
      2 5
      3 6
      The last switch (Oscillation) is a momentary SPST footswitch with lugs numbered
      1
      2

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    2. I've got all of that so far, but is this describing nocentelli's design where it's not actually a DUB On-DUB Off toggle, but a DUB-OSC toggle?

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  9. I would like to accomplish a few things with my build of this awesome pedal:

    1) limit the maximum delay time to around 700ms (like a real tape echo)
    2) increase the linearity of the delay time control

    If anybody could walk me through how best to do that, I'd be much obliged!

    Also, where exactly on the layout is the high- and low-pass filtering done to the delay repeats so I can possibly tweak those values as well? Hard to tell just looking at the vero without a schematic.

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    1. Hey, how did you manage to achieve your goals? Would really love to know, I know it’s an old comment but hoping someone can help!

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  10. Just finished building, sounds amazing!!

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  11. This is a great sounding delay! Thanks! If I was to build this again, I'd exclude the bypass switch and use a 3pdt instead of the 2pdt and add a 2 color LED to the extra poles.

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  12. hello, i like the delay. is there away to build another and link them together for same long delay with much better sound quailty? thanks

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  13. Just built this. Sounds great. Worked first try. Wired the dub/osc switch like nocentelli said. Might need to play around with some values on the oscillation part. It only goes into oscillation if the feedback is set around the middle or higher.

    Tried a deprofundis modboard on it for some trippy dub goodness.

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  14. I'm having a slight detune on the repeats, anyone else had this issue?

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    1. I just finished mine, and I get that too, just slightly and not always. It almost feels like some high signal gets bled into the speed voltage somehow.

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    2. I did some playing around with my oscilloscope. I noticed that the 5v rail for the PT2399's drops noticeably, at least 4-5% the louder the signal is.

      When the delay time is shorter the voltage drops even more, almost 10% down from the original 5v, and it drops even further when the signal is loud (lots of feedback for example).

      I suspect that the power rail is getting dragged down, which is causing the chip to run at a different speed, thus detuning the repeats.

      either the 7805 is not strong enough to regulate the voltage properly, or we need to up those 47uF caps significantly.

      I haven't tried it with a power supply yet, i've only been using 9v batteries, so perhaps a stouter 9v input will solve the problem.

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    3. A power supply does not solve the problem. Maybe my caps are bad, I'm not sure why else the 5v rail would be dropping so much. As it is, the pedal is unusable because the delays are out of tune with the sound.

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  15. So I built this off the schematic not this vero but it's not delaying but does pass my signal through the tl072 any ideas?

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  16. What is the LED+ connection on the board please? Does it use different offboard wiring than usual?

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    1. The board contains a 4K7 current limiting resistor so you don't have to add another one offboard for the LED. So that connection goes to the LED anode, with the cathode then going to the switch

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    2. Ok thanks very much. I like that better than a LED resistor hanging off the LED. I appreciate the quick response and thanks for the great site. My kids and I have built a lot of projects from here.

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  17. Hi - has anyone built and tested this layout ? I've just built it, and all I can get is the clean sound. Comparing this vero layout with others, the 47pF and 100pF look like they might be swapped ? Swapping them back still doesn't seem to fix it though. I've also tried taking the DPDT out and just using two momentary switches. Still no luck.

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  18. A couple of people claim to have got this layout working, and those small cap values are not critical to the circuit's operation.

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