Alright you primitive screwheads...
(With proper transitor selection)
Still working on the etching process and learning more Illustrator but figured this was good enough to use. The etch was shallow(eBay etchant is too weak, stronger stuff coming) and I ended up sanding trough the paint in a couple of places and sawed off the shotgun with acetone when cleaning. Oops.
In short:
I like this circuit. Build one. It does one thing but does it really well. I tried it with the 3904s and it sounded okay but it had room for improvement. Also, what's the point of having a crap ton of different transistors just to stick jelly beans everywhere. So, I auditioned some transistors and wound up with the following soldered into the circuit
Q1 2N3567 40hfe
Q2 PN3569 79hfe
Q3 2N3567 81hfe
Upped C1 and C7 to 120n for a little more bass throughput.
I spent a lot of time trying out candidates for Q3 and kept coming back to the Teledyne 2N3567. This gave me a good build of harmonics without any fizz at all. There may be a subharmonic in there even? And it was louder than every other transistor, regardless of hfe. Like, really loud! Unity is about 10 o'clock. I suspect it's a result of a higher vsat rating. Funny, a 2sc1815 has that distinct TS top end fizziness in Q3. Some transistors(looking at you 2N3392Brass master transistors)) turned it into a box of oscillating farts. But the 3567 just outputs nut sacks full of doom.
I wanted this to not be a wall of fizz, instead providing harmonic overtones while maintaining clarity and some note separation-not sludge, that's a different genre with a few bpm added. Needed to push a mild dirty tube amp over the edge. It does all the things. I'm very happy.
The artwork is part of my slow etching learning process. Good ole Ash and the Evil dead skull. The 3mm LEDs are epoxied in place an wired parallel to one another. I would usually use separate CLRs but already had the board populated so I improvised and just matched the Vf of the LEDs instead.
I was off a little bit on my measurements in Illustrator, hence the cockeyed PCBs. 2 LEDs soldered together and stuck in epoxy are not very forgiving to movement.
I did clean the flux off of the solder side and still have some cleanup to do but hey, no guts-no glory. So here ya go.
Already worked out another version of the artwork to practice etching more and to gift. Actually adjusted the kerning on this one but need to adjust LED placement.
Going to use these LEDs that are on order from Ali. The protruding portion is only a 2mm diameter and will provide a lot more surface for the epoxy to bond without any chance of shorting to the enclosure. Goal will be getting them flush to the face.
(With proper transitor selection)
Still working on the etching process and learning more Illustrator but figured this was good enough to use. The etch was shallow(eBay etchant is too weak, stronger stuff coming) and I ended up sanding trough the paint in a couple of places and sawed off the shotgun with acetone when cleaning. Oops.
In short:
I like this circuit. Build one. It does one thing but does it really well. I tried it with the 3904s and it sounded okay but it had room for improvement. Also, what's the point of having a crap ton of different transistors just to stick jelly beans everywhere. So, I auditioned some transistors and wound up with the following soldered into the circuit
Q1 2N3567 40hfe
Q2 PN3569 79hfe
Q3 2N3567 81hfe
Upped C1 and C7 to 120n for a little more bass throughput.
I spent a lot of time trying out candidates for Q3 and kept coming back to the Teledyne 2N3567. This gave me a good build of harmonics without any fizz at all. There may be a subharmonic in there even? And it was louder than every other transistor, regardless of hfe. Like, really loud! Unity is about 10 o'clock. I suspect it's a result of a higher vsat rating. Funny, a 2sc1815 has that distinct TS top end fizziness in Q3. Some transistors(looking at you 2N3392Brass master transistors)) turned it into a box of oscillating farts. But the 3567 just outputs nut sacks full of doom.
I wanted this to not be a wall of fizz, instead providing harmonic overtones while maintaining clarity and some note separation-not sludge, that's a different genre with a few bpm added. Needed to push a mild dirty tube amp over the edge. It does all the things. I'm very happy.
The artwork is part of my slow etching learning process. Good ole Ash and the Evil dead skull. The 3mm LEDs are epoxied in place an wired parallel to one another. I would usually use separate CLRs but already had the board populated so I improvised and just matched the Vf of the LEDs instead.
I was off a little bit on my measurements in Illustrator, hence the cockeyed PCBs. 2 LEDs soldered together and stuck in epoxy are not very forgiving to movement.
I did clean the flux off of the solder side and still have some cleanup to do but hey, no guts-no glory. So here ya go.
Already worked out another version of the artwork to practice etching more and to gift. Actually adjusted the kerning on this one but need to adjust LED placement.
Going to use these LEDs that are on order from Ali. The protruding portion is only a 2mm diameter and will provide a lot more surface for the epoxy to bond without any chance of shorting to the enclosure. Goal will be getting them flush to the face.
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