Thursday, 2 June 2022

EarthQuaker Devices Disaster Transport

 Schematic is avaiable HERE.



34 comments:

  1. Altho I'm currently in love with your drawing of the Montavillian Echo, I think I may have to try this one too. Since I think I can all ready see where I will need to move the delay coupling capacitor in order to add a trails bypass switch...

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    1. I built the Montavillian echo, but found the repeats didn't have the same level of clarity as as the deep blue delay or the magnetic echo (YMMV, of course!)

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    2. Hi,
      I also built the Montavillian echo, and I loooove it (and I already have several tape & BBD delays, as well as other DIY PT2399 delays). I think the sound of the Montavillian is very, very nice :)

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    3. Hey Ian! The cool thing about the Montavillian is that it can do long delay times and also have usable trails bypass (I'm insane, I HATE it when the delay cuts off in bypass). Even with a 100k delay pot for 1000ms, it has NONE of the characteristic digital bubbling that you get from PT chips. Of course, then you have to add a master volume to the end of the circuit because the op amp boosts your signal quite a bit.

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    4. On reflection, I could have maybe popped a different chip in there for a fairer test! I still maintain the magnetic echo has the longest most hi-fi repeats without the usual tape hiss noise we expect from a pt2399

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  2. My first delay build was the Disaster Transport Jr. I love it. I may have to upgrade to this one though.

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    1. The Disaster Transport Jr is less colored than the Montavillian.

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  3. I was in the process of building a JR with an off-board LFO but it looks like I should just build this version instead, definitely gonna throw a feedback stomp switch on it too.

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  4. tag it, my dude. TAG. IT. Just finished it and it does indeed do all the right delay sounds. I have not yet done all of the mods that I want to do on this circuit yet, but I wanted to build it up stock first. ROCK.

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    1. Awesome Chris, you are the man.
      Looking forward tp see your mods on this one!

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  5. how do you wire the mod switch? how would I count the pins? renegadrian

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    1. When looking at the bottom of the switch it would be wired as below.

      1 4
      2 5
      3 6

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    2. This comment has been removed by the author.

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  6. Built and sounds awesome, super happy with it! Was wondering if anyone had an Idea how to get rid of the Ticking caused by the Mod LED? Or have I made a mistake somewhere? Pretty sure If I could figure out a way for the LED to just dim itself and not turn on and off the ticking would go away. Thanks for the layout and everyone apart of this little community!

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    1. Totally agree with you,sounds awesome indeed!But like you I notice the modulation lfo in the signal,a(soft, -60dbu) click when ever it jumps from one end to the other,also when the led is not connected btw, even in the dry signal when the mix is set all the way to the left.Did you find a sollution for this by any chance?And to others that build this layout,does this happen on your built too?Thanks in advance for anyone that has suggestions.

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    2. correction" -60dbfs " facepalm :)

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  7. I wonder if anyone else has had an issue with the 4558 oscillator not working correctly? I have built this circuit twice and the LED will not oscillate in either one; the rate knob only turns up the intensity of the solidly lit indicator bulb. A couple of times it has randomly worked for a few seconds, so I'm wondering if this type of oscillator is unstable or overly sensitive to component values in order to function. Any help sure would be appreciated, and yes, I've checked against the schematic and done several hours of troubleshooting and built two separate circuits completely just to be sure:)

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  8. I haven't tried the version with modulation. I have had a lot of trouble in the past with faulty 4558 chips. I kind of hate them as a result. If I were you, I'd try a different chip altogether.

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    1. I see a schematic call for a 4558 and say oh - so a 5532.

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    2. Interesting... Each 4558 behaves a little bit differently... TL chips don't work at all, neither do 5532's... in any case, none of them work reliably. Such a disappointment, as I was hoping this was the answer.

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    3. Turned out to be a leaky 470n capacitor. Never had that happen before... this is an excellent modulation delay now!

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  9. I built this and it works amazingly well. however a bit of an issue. when I plug it into a power supply it goes nuts and is unusable, when i use a 9v battery there is no problem. anyone got an idea whats going on here?

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    1. nm, figured it out. I had the 7805 backwards. derp derp.

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  10. Can someone confirm that the two 100nf capacitors in the middle are definitely NF not PF, just wondering why they are yellow and not red like the other 100nfs.

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    1. They are 100nf - that is correct. The reason they look that way is it's recommended to use ceramic disc capacitors for those particular ones because ceramic handles AC ripple current better. You can use film and would almost certainly hear no difference.

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    2. That's great, thanks for the info. I've been using box capacitors where possible, I'll see if I can dig out some ceramics. Would green caps be better than box ones do you think?

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    3. Green caps are mylar film, so it would be about the same as your other film caps. Honestly, it's running at 9v so I kind of doubt you'd hear any difference using just whatever you have. Worst case scenario you end up with a little unwanted noise.

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  11. May I ask how am I supposed to solder the 7805 ? On which pins precisely?

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  12. The DPDT switch is a on-off-on or on-on-on switch?

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    1. It's on-on. A common 3pdt footswitch works - just leave a row empty.

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  13. Does anyone have a schematic for the legacy reissue? I'd love to make that one.

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