One of the more interesting Big Muff derivates out there. The first three stages is a basically a Dice Works Muff Diver which itself is based on a 1972 era Triangle Big Muff. The tonestack is whats make it standout from the crowd; an active transistor based two band eq.
And demo of MTK's build
It seems to me a nice Big Muff variation. It's not mid scooped, that could be useful, and the Bass and Treble controls make it versatile.
ReplyDeleteI traced it (not build) and I didn0t find anything wrong, but I have doubts about the 820R resistor from the emitter of Q3. Is it too much high? If this is a Triangle version based it should be 82R.
Yeah, 820ohm is a bit high. Take a look at Dice Works Muff Diver at the bottom of this link.
Deletehttp://www.bigmuffpage.com/Big_Muff_Pi_versions_schematics_part3.html
It is almost the same except for the switches. And the base resistor at Q2 is missing here as well.
I prepped the board for this one before I left for work. I should be able to get this done later today.
DeleteOk, Fuzzhead.
DeleteThanks MTK.
Board - https://i.imgur.com/maPqs4P.jpg
ReplyDeleteDemo - https://www.youtube.com/watch?v=jitrVPAt56A
I went with a 91R for the Q3 emitter. The 820R worked but I like the lower resistor in there better. I also subbed the 2.2nF caps with 2.7nF because I'm out of 2.2's.
The circuit sounds good but holy hell the bass is insane. It's kinda flubby at noon and shakes the speakers beyond, I mean that literally. This can kill a cab. It worked best for me around the 10 o'clock position at the volume I was playing. I'll give it a shot on bass and see how that goes.
Heck yeah! Thanks.
DeleteThat section sounds very powerfull for sure. Might try it in other projects and add a Mid band.
I'll listen the demo later. I emulated the frequency of this cricuit with the software, and I noticed the amount of the bass.
DeleteIf you change, for example, the 100nF cap in the upper left corner with a 22nF you will cut the bass.
The 22nF works perfectly. Thanks, man.
DeleteGood! Indeed, this schematic seems bass boosted in flat setting. I want to watch with more attention some demos.
DeleteElijah-Baley, can you show us a picture of what you emulated?
Deletehttps://www.youtube.com/watch?v=mrm3LkP-XIo
DeleteThat's a direct recording into Reaper, just straight circuit. Starts out with the bass and treble centered, then bass all the way down, then up and back to center. Then treble down, then up and back etc...
The room shakers are at :35 and 1:48
Sure, AlexS.
DeleteThis is the diagram with the original frequency and the one with the 100nF cap mentioned above changed with a 22nF.
https://i.imgur.com/u1igSbB.jpg
The difference seems enough drastic, just looking at it, at least. I didn't built this, so I can hear it.
A 47nF cap could be a good choice, cutting low end, but not so much.
Thanks. You say it should be very heavy even flat. MTK's video is also very bassy.
DeleteBofore the EQ section, this circuit is like the Dice Works (scroll to the bottom):
http://www.bigmuffpage.com/Big_Muff_Pi_versions_schematics_part3.html
It has that coupling cap you mention as switchable 100n/10n. The tone on that is the classic scoop, but maybe it also had a lot of low end that needed trimming. In fact one of the Dic eWorks versions had 3 of the coupling caps switchable to smaller values.
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ReplyDeleteThis is fab! Thanks! If you could do the Fat General at some point that would be great. Cheers, Ben.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteJust made one of these with BC108's after seeing the release of the new limited edition. Hfe around 300. Sounds awesome!!
ReplyDeleteJust built this, but for some reason My Treble and Bass knobs don't do anything. The sound is distorting and strong, but can't eq it. Any ideas?
ReplyDeleteI had issues with mine at first too. It sounded choked. I found that I'd missed a resistor leg (maybe 6 months later). The layout works and it's honestly a great fuzz pedal. Double and triple check that you didn't miss something. The layout works perfectly.
ReplyDeleteHi Tom! I forgot a 100nf capacitor 🤦🏻♂️ the only one that goes horizontal. Now it's everything working great need just to box it (:
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