Treeler hat u.a.
2 x 3280
DG409
2k Tempco
Teezer special parts:
1) CA3280 OTA. This is the heart of the VCO. I tried an LM13700 but it was quite a bit inferior. Bridechamber is stocking the 3280, and I have a large stash of my own, which I will let Scott have if he needs more.
2) VN0104 MOSFET. Two of these are used for the integrator discharge switches. The switches have to swing a large voltage, due to the bipolar signal, and the low capacitance of this device makes a big difference in the reset signal. They are not rare or expensive, really, probably just a bit unfamiliar to most builders. 42 cents at Mouser.
3) A pair of matched 4.3V zener diodes. Buy 10 or so, measure their breakdown voltages and pick the best pair.
4) One pair ea of LM336-5 for the subregulated 5V supplies.
5) One pair ea of 3.3V zeners and 5.1V zeners for comparator decoupling.
6) MAT03 matched super transistor pair for the expo current source. SSM2220 is probably OK and has the same footprint. I've been using 2SA798, and the board will also take that.
7) One OPA2227 precision opamp for the expo converter circuit. OPA2134 would be just about as good.
#eight) 2 ea OPA134 and 2 ea OPA2134. Where low leakage/high speed are needed.
9) 2 ea LM311 high-speed comparators. For the two ramp resets.
10) Other opamps: 1 ea TL072 (or similar); 2 ea TL071 (or similar); 2 ea LM741 (for spike reduction).
11) 2k 3300 or 3500 ppm tempco resistor.
12) 6 ea ferrite beads. The power supply is split into three separately decoupled branches.
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Beides würd mich evtl. interessieren. Allerdings auch nur als Kits. Möchte meine 3280 nicht dafür opfern
