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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.


12 comments:

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

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

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  3. 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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    1. 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.

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

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

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

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

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  6. 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!

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  7. Would AC128 work instead of OC139?

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

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