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Put together my first guitarPCB Emexar pedal and added an after blaster board. Enclosure is temporary while my Tayda order finishes.
The Dist+/250 is pretty much my all time favorite pedal to kick on for a screaming solo, so this build was a no brainer. I decided to put the AB on a switch, but I’m not sure why, I have it turned on always (go big or go home right?). Just made wiring more complex.
ALSO I friggin spaced out and drilled the switch hole on the wrong side which made me have to rotate the AB board to get everything to fit. Basically the switch addition made everything 100x more complex than it needed to be, but I learned a few lessons.
Lastly it is build to Dist + values, however I used the extra diode slot for asymmetric clipping and I really like it. I used 3x USSR D9E that I measured and selected to be pretty close to the 1N270 diodes I also have. The D9E have just a scootch lower forward voltage, so they kick on sooner, and are ever so slightly more compressed sounding, but it’s good. The asymetric is cool too. Seems to add a little something extra to the distortion, its subtle but appreciable.
The build was really straight forward, after I fixed the diodes I put in backwards (soviet diodes mark the anode) I didn’t run into any issues. I just hope that my Tayda enclosure UV/drill order arrives soon so I can re-house this guy in the actual stomp box I had made for it!
Looking good, and sounding likewise, no doubt. I should revisit my own build from some time back; thanks for the inspiration.
These were the selection of diodes that I was pondering over. I was shooting for finding three of a kind that were ~0.28fv. I’ve always used that value for germanium hard clipping diodes….not exactly sure why…..habit and sounds good to me I suppose. I for sure recommend the asymmetric config. I really dig it.
What kind of surprised me was that the 1N270s that I have were the diodes that had the most deviation in fv. After testing 10 or so of the 270’s I got impatient and started checking the 1N60’s. They were a tighter lot, but when I got to checking the D9E just about every single one was 0.28 on the nose, so that’s what went in there.
My last thought on the build is that next time I do an AB board I think I will omit the on/off toggle for the boost and instead leave it always on, but replace the vol trimmer with an external pot. Either that or put the AB boost on a foot switch instead of a toggle, since that would be actually useful for me.
I will add this about the After Blaster board. I used a J201 that was known to be “in spec” (previously tested), biased it, and well….it spits fire. I had the trimmer set to noon for the volume and when I flicked it on for the first time it was VERY loud. I bet that different JFET’s will all be different so it might be worth socketing and experimenting one time. You will likely want to adjust it tailored to your set up.
I would for sure recommend starting low, maybe even all the way down to start then slowly bring it up. Mine ended up at 1/4 of the way up and its plenty spicy.
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