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Monday, June 4, 2018

EarthQuaker Devices Crimson Drive (3-knob)

What? A Monday post? Yep. This week is EarthQuaker week. EQD is easily my favorite pedal company, and I own more of their pedals than any other builder. Not to mention I've learned a lot about pedal design from Jamie's work. So this week I'll be posting 3 EQD circuits and hopefully a video to go along with this week's Fuzz Friday.

To kick EarthQuaker week off, here's the now discontinued Crimson Drive. Did the 2-knob version ages ago, but the 3-knob version was recently posted on FSB so I gave it an update. Beyond the addition of the tone control, there's a few capacitors removed compared to the 2-knob version. The germanium transistor is also different–an NPN instead of the PNP–and the germanium transistors were swapped from 1N60Ps to 1N34As. Easy fit in a 1590B with board mounted pots.


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12 comments:

  1. FacundoJune 4, 2018 at 2:13 PM

    Me gusta la idea de semana EQD... también son mis preferidos! Gracias por compartir tu trabajo!

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  2. PeteJune 5, 2018 at 1:19 PM

    Can't wait to see what the next two EQD posts are!

    ReplyDelete
  3. KeelagrammJune 5, 2018 at 3:47 PM

    It works! I used a GT404E germanium transistor and a couple germanium diodes. Sounds great with 18 volts, but gate-y with a 9v battery (need to bias probably). Anyway, the layout is certainly verified!

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    Replies
    1. Effects LayoutsJune 5, 2018 at 5:24 PM

      Thanks for verifying!

      Delete
    2. KeelagrammJune 6, 2018 at 2:13 PM

      Thanks a lot for all your work! I have to admit it was a dead battery, lol. Everything works like a charm with no adjustment. I used d9v and d311 ge diodes.

      Delete
  4. ZZOYDJune 6, 2018 at 11:31 AM

    I used kp303a & mp38, d9 diodes (soviet germanium), nice sound, thanks!

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    Replies
    1. UnknownJune 7, 2018 at 2:42 AM

      Hi, I used the MP38 with d9 diodes and j201. there is not a lot of gain... what Hfe did you use?

      Delete
    2. ZZOYDJune 7, 2018 at 7:56 AM

      I just removed silicon diode, i had the same problem. Hfe near 100. I tried to use kp303g - any diferences, i left it!

      Delete
  5. JL P-0'sJune 11, 2018 at 10:36 PM

    It's amazing...but, Which values should be get in the germanium? Whatever is good?

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  6. G.G.June 15, 2018 at 2:11 PM

    Thanks for the layout and the circuit breakdown video! I built mine with a GT404D and a couple Russian D310 diodes and it sounds really great. Thanks again!

    ReplyDelete
  7. klutzNovember 13, 2018 at 7:06 AM

    Would AC128 work instead of OC139?

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    Replies
    1. Effects LayoutsNovember 13, 2018 at 8:08 AM

      The AC128 is PNP, so it won't work without some modification to the circuit. The AC127 is NPN and you coud use it.

      Delete