4 ms·
Show HN: SevenFortyFun, a transistor level op amp kit
- kazinator 12y agoHmm. That Q8/Q9 current source being duplicated into two mirrors in separate stages (Q17/Q18 and Q19/Q20) seems quite pointless in a discrete amplifier. In a realistic discrete amplifier, even if you still used the two mirrors, you'd program them separately with just a resistor. The two stages do not require identical currents. I suspect this usage has to do with what's easier to fabricate on silicon. In the VBE multiplier around Q16, I would add a potentiometer to adjust the quiescent through the output stage, even though the `41 of course has no such thing.
- turnip1979 12y agoI don't understand why they need kickstarter funds to test if the board works. I thought there are services out there that print one off circuit boards for reasonable amounts.
- fernly 12y agoSo I can't figure out why this product should exist (as a product, vs. a lab exercise). On the KS page it only mentions "You can finally get the chance to understand whats going on inside those ICs!" Which is worthwhile, I suppose, to a minority of hardware designers, just as learning assembly language is worthwhile to a minority of programmers. But does that translate into a business plan? What is the market for such kits?
- deleted 12y ago[deleted]