Another Dunwich trace by evilarsen, AlexS and fuzzhead.
I believe this one was made on custom order and/or was a on/off product. However, compoent values varied over time but we added some notes at the bottom of the layout and schematic for the most significant changes that is worth experimenting with:
Input capacitors connecting to the input cap blend control (Depth) varied quite a bit. I ended up with a 15nF for C2 and an 1uF for C1 with a 100kC Depth control.
The other thing is one of the clipping diodes at Q4. Most units had a germanium diode but a few had a silicon transistor in TO-18 casing wired as a diode. Both layouts bellow have slots for both components but remember to use one of them, NOT both.
Two layouts, one normal and one with 1.5W carbon comp resistors. Both is verified.
Triple verified !
ReplyDeleteI put a 470nF on C1 it's enough for me (but i can change it's slotted)
Add a switch to ge diode or silicon diode.
For Q5, what did you choose? I tried several transistors but none pleased me
Little late, but I used an MP40 as a diode, a red led and a MP42b in series with a 1N4004 in an on/off/on dpdt with the red on lugs 2 and 5
DeleteI tried a few different trannies for Q5. BC108 and MP38 was quite "meh". 2N1308 sounded really good though, almost as good as a ge diode. I ended up skipping the transistor and soldered in a random SFD112 ge diode which sounds great.
ReplyDeleteI built the non mojo layout but had to add the 15k to Q4's collector by moving the diode to the side.
ReplyDeleteI used 15n & 2n2 in depth pot for a wide range. Then 2222a's and a
Schottky diode for clipping.
Thanks for reminding me.:-) Fixed.
DeleteUpdated with values from the new all-silicon version. 33n-1uf for input caps.
DeleteHi! what hFe's would you recommend for Q1/Q2/Q4?
ReplyDeleteAlso, could I request something similar to the Runoffgroove Splitter-Blender, with a phase switch? I am a lot more interested in the splitting part, to run 2 amps with different signal paths at the same time.
My 2N2219As ranges from 150 to 250 Hfe. Metal can 2N2222A's seem to be a good option. Spec is almost identical except for the voltage rating.
DeleteI'll take a look at the Splitter-Blender but I don't know when. Need to finish some layouts before I start on a new one.
Thanks! - I have no metal transistors, but I have some plastic 2n2222As in that range, will most definitely try this one out.
DeleteHello kind folks! Is there any way I could brighten this up a little bit?
ReplyDeleteI don't know. It depends on your values for C1 and C2?
DeleteYou can also try smaller values for 820pF and/or 100nF at column 8.
Do you have the 470p as a 470n? It's pretty bright with a 1n and 2.2u in C1 and C2
DeleteNon mojo has a typo I believe, 470nf should be 470pf
ReplyDeleteThanks for spotting that. Layout updated.
DeleteMine
ReplyDeletehttps://ibb.co/Bz3pWtw
https://ibb.co/HtL34cW
Doing this a few time ago but never finish it. By the power of the gray skull !
I add a switch for clipping with pair of silicon or germanium diodes works both with the Led. I really love this fuzz !
For those that built the non mojo version does the LED light up. I built this with a Germanium diode no transistor. I have plenty of gain on tap and it sounds great just want to make sure all is good. It’s hard to tell which way D3 goes in the layout because it shows the cut below. I put cathode (stripe) facing down. I think it’s right.
ReplyDeleteHey Matt. You did the the right thing, cathode is facing down. My LED barely flickers so that is normal, keep in mind that LEDs doesn't necessarily have to light up to clip the signal.
DeletePerfect. Thanks. This is a great sounding fuzz.
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