Reply to Bill Sloman's post at 11:41 PM in "coil impedance".

Tantalums are prone to detonation, if handled badly. And they are often handled badly.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

I've got the file on my computer under the file name "John May

John Larkin may be in the habit of not taking data sheets seriously, but more serious people are more careful. George Kent and Cambridge Instruments designed them into products, and they didn't "detonate" in the field. Junior engineers did occasionally solder them into prototypes the wrong way around, but they didn't do it twice.

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InstName C10 SYMATTR Value 10p SYMBOL res -112 272 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R8 SYMATTR Value 10k SYMBOL res -320 272 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R9 SYMATTR Value 560 SYMBOL cap -992 256 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C5 SYMATTR Value 1µ SYMBOL cap -608 272 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C8 SYMATTR Value 1µ SYMBOL res -272 1088 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R6 SYMATTR Value 220k SYMBOL cap -304 1056 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C4 SYMATTR Value 1µ SYMBOL diode -400 896 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D3 SYMATTR Value 1N914 SYMBOL diode -320 896 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D4 SYMATTR Value 1N914 SYMBOL diode -240 896 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D5 SYMATTR Value 1N914 SYMBOL Opamps\\LT1013 448 528 R90 SYMATTR InstName U1 SYMBOL polcap -1392 1376 R0 SYMATTR InstName C3 SYMATTR Value 100µ SYMATTR SpiceLine V=6.3 Irms=0 Rser=0.9 Lser=0 mfg="AVX" pn="TAJD107M006" type="Tantalum" SYMBOL polcap -1296 1376 R0 SYMATTR InstName C6 SYMATTR Value 100µ SYMATTR SpiceLine V=6.3 Irms=0 Rser=0.9 Lser=0 mfg="AVX" pn="TAJD107M006" type="Tantalum" TEXT -1992 -16 Left 2 !.tran 0 10 0 1u startup TEXT -2000 -128 Left 2 !.options plotwinsize=0 numdgt=15

"Bill Sloman" snipped-for-privacy@ieee.org wrote in message news:10f19b8$18b8d$ snipped-for-privacy@dont-email.me...

I've never seen that before and it does not simulate at a reasonable speed in 24.1.10

It is also not equivalent to what JM actually posted which was as follows.

This does simulate and has good performance, as would be expected from JM. The word "tantalum" is not mentioned.

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cap -1792 320 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C9 SYMATTR Value 10p SYMBOL cap -800 32 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C10 SYMATTR Value 10p SYMBOL res -112 272 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R8 SYMATTR Value 10k SYMBOL res -320 272 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R9 SYMATTR Value 560 SYMBOL cap -992 256 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C5 SYMATTR Value 1µ SYMBOL cap -608 272 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C8 SYMATTR Value 1µ SYMBOL res -272 1088 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R6 SYMATTR Value 47k SYMBOL cap -304 1056 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C4 SYMATTR Value 10µ SYMBOL diode -400 896 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D3 SYMATTR Value 1N914 SYMBOL diode -320 896 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D4 SYMATTR Value 1N914 SYMBOL diode -240 896 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D5 SYMATTR Value 1N914 TEXT -1992 -16 Left 2 !.tran 0 10 0 1u startup TEXT -2000 -128 Left 2 !.options plotwinsize=0 numdgt=15 TEXT -2000 -72 Left 2 !.lib opamp.sub TEXT -1992 32 Left 2 !.save v(vout)

After fixing microfarad extraneous character issues I found that the circuit you posted with the "tantalum" capacitors does simulate. But it is not equivalent to the circuit JM posted and it has much worse harmonic performance. And I have never seen it before.

The only circuit I clearly remember (very very clearly) is the one with the 470uF capacitor which JM certainly did post because I just took it from his post.

So I suspect that the "tantalum" version is a creation of your own which you never posted until now.

It simulates fine for me, but since I'm still running under Windows 7 I'm running LTSpice 17.0.37.0. It's not quick - about 11msec/sec but not too bad.

It has C6 as 470 Farad - not nF or uF but farads!

When I finally nerved myself to go back to the thread and downloaded JM's .asc file from February 15 2025 C6 was 470uF, which is huge, but not 470F!

It simulates fine, at about 13msec/sec. The amplitude control loop is a bit underdamped

We were having trouble with getting LTSpice to display uF values at the time. Presumably I tweaked it get something more sensible. I do remember that it needed quite a lot of capacitance at C6, and I couldn't get it to get by with much less than 100uF at C3 and C6, equivalent to 47uF directly between the two emitters.

We don't often use tantalums these days. They do have about the right ESR to stabilize some older voltage regulators. They are reliable if peak current stays low, and if voltage derated at least 2:1.

We use polymer aluminums whenever we can. Low ESR, low ESL, don't detonate or dry out. Adding ESR isn't difficult.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

It's clearly going to have more rectifier ripple feed-through, which should equate to more harmonic content in the output, but it struck me as a more practical circuit, at the time.

I probably didn't post it anywhere. It was just the version on my hard disk.

But when you posted your version here just now it had 470F rather than

The 470uF capacitor would almost certainly have to be an electrolytic part (and most likely a tantalum part) in practice. You did object to the size of C6 and claimed that you put together your eight transistor version to get rid of it. The basic idea was interesting, but you didn't explain how it worked, and JM demonstrated that four transistors were enough. It took me a while to get my head around even that, and when I posted my five transistor version I did explain what I thought was going on, rather expecting to have some misconception or other jeered at.

It was probably a tidied up version of what JM posted. I do remember playing with it and finding it needed a lot of by-pass capacitance, at R17 and R21. which would have needed to be electrolytic if it wasn't going to be bulkier than the rest of the circuit put together.

I've seen them in catalogues, but haven't designed them into anything yet.

They are great. The ones we use zener softly at about 1.4x rated voltage and just get warm. They tolerate reasonable reverse voltage.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

"Bill Sloman" snipped-for-privacy@ieee.org wrote in message news:10f1s7j$1d4bm$ snipped-for-privacy@dont-email.me...

As per my other thread it also simulates here after fixing Microfarad character issues. What is the harmonic performance?

(I'd start thinking about moving off Windows 7 if I were you. I'd also get rid of the Norton crapware your headers suggest you have installed. Windows 10 IoT LTSC works fine for me and has just installed the November update.)

Er no Bill. Copying my post into a new text file shows 470µ If you delete the character between 470 and µ then you get

This reminds me of schematics I can remember from the past which would spell it out as 470 Microfarad. Probably because they didn't have a Greek letter mu. Sometimes it would be shortened to 470MF because 470 Mega Farads would be insane so it obviously meant 470 Microfarad.

So no apology for telling me I produced the "tantalum" version? Yes I know those weren't your exact words but close enough. No problem. And no surprise.

The circuit below, which has been fully nanofaradated, uses two 1000MF capacitors the way you connected them. It has excellent performance.

But the whole point of the circuit I arrived at (with JM's help) was to produce an implementation without any huge capacitor at all.

Version 4.1 SHEET 1 3020 1796 WIRE 80 -208 -288 -208 WIRE 800 -208 160 -208 WIRE -288 -96 -288 -208 WIRE 80 -96 -288 -96 WIRE 400 -96 160 -96 WIRE -288 32 -288 -96 WIRE -176 32 -288 32 WIRE -32 32 -96 32 WIRE 48 32 -32 32 WIRE 208 32 128 32 WIRE 256 32 208 32 WIRE 400 32 400 -96 WIRE 400 32 320 32 WIRE 464 32 400 32 WIRE 608 32 544 32 WIRE 656 32 608 32 WIRE 800 32 800 -208 WIRE 800 32 720 32 WIRE -1488 48 -1488 -32 WIRE -1328 48 -1328 -32 WIRE -1152 48 -1152 -32 WIRE -864 48 -928 48 WIRE -736 48 -800 48 WIRE -288 144 -288 32 WIRE -176 144 -288 144 WIRE 208 144 208 32 WIRE 256 144 208 144 WIRE 608 144 608 32 WIRE 656 144 608 144 WIRE -928 160 -928 48 WIRE -864 160 -928 160 WIRE -736 160 -736 48 WIRE -736 160 -784 160 WIRE -32 160 -32 32 WIRE -32 160 -112 160 WIRE 400 160 400 32 WIRE 400 160 320 160 WIRE 800 160 800 32 WIRE 800 160 720 160 WIRE 832 160 800 160 WIRE -1488 176 -1488 128 WIRE -1328 176 -1328 128 WIRE -1328 176 -1488 176 WIRE -176 176 -288 176 WIRE 256 176 224 176 WIRE 656 176 624 176 WIRE 224 208 224 176 WIRE 624 208 624 176 WIRE -1776 272 -1920 272 WIRE -1488 272 -1488 176 WIRE -1488 272 -1696 272 WIRE -1152 272 -1152 128 WIRE -1056 272 -1152 272 WIRE -928 272 -928 160 WIRE -928 272 -992 272 WIRE -848 272 -928 272 WIRE -736 288 -736 160 WIRE -736 288 -784 288 WIRE -672 288 -736 288 WIRE -416 288 -608 288 WIRE -288 288 -288 176 WIRE -288 288 -336 288 WIRE -208 288 -288 288 WIRE 208 288 -128 288 WIRE 400 288 400 160 WIRE 400 288 208 288 WIRE -848 304 -928 304 WIRE -1920 336 -1920 272 WIRE -1856 336 -1920 336 WIRE -1760 336 -1792 336 WIRE -928 336 -928 304 WIRE 400 336 400 288 WIRE -1488 384 -1488 272 WIRE -1488 384 -1648 384 WIRE -1648 416 -1648 384 WIRE -1920 448 -1920 336 WIRE -1872 448 -1920 448 WIRE 400 448 400 416 WIRE 512 448 400 448 WIRE -1760 464 -1760 336 WIRE -1760 464 -1808 464 WIRE -1712 464 -1760 464 WIRE 368 464 336 464 WIRE -1872 480 -1920 480 WIRE -1488 496 -1488 384 WIRE 368 496 368 464 WIRE 400 496 400 448 WIRE 512 496 512 448 WIRE -1648 544 -1648 512 WIRE -1552 544 -1648 544 WIRE -1920 560 -1920 480 WIRE -1648 576 -1648 544 WIRE 384 608 384 560 WIRE 512 608 512 576 WIRE 512 608 384 608 WIRE -32 656 -32 160 WIRE 208 656 208 288 WIRE 384 656 384 608 WIRE 800 656 800 160 WIRE -1648 688 -1648 656 WIRE -32 752 -32 720 WIRE 208 752 208 720 WIRE 384 752 384 720 WIRE 800 752 800 720 WIRE -1152 848 -1152 272 WIRE -400 880 -416 880 WIRE -320 880 -336 880 WIRE -240 880 -256 880 WIRE -160 880 -176 880 WIRE -32 880 -32 832 WIRE 208 880 208 832 WIRE 208 880 -32 880 WIRE 384 880 384 832 WIRE 384 880 208 880 WIRE 800 880 800 832 WIRE 800 880 384 880 WIRE -1488 896 -1488 592 WIRE -1216 896 -1488 896 WIRE -1904 944 -1904 912 WIRE -1904 944 -1952 944 WIRE -1952 960 -1952 944 WIRE -1904 976 -1904 944 WIRE -1152 976 -1152 944 WIRE -1152 976 -1280 976 WIRE -32 976 -32 880 WIRE -416 992 -416 880 WIRE -320 992 -416 992 WIRE -160 992 -160 880 WIRE -160 992 -256 992 WIRE -1488 1040 -1488 896 WIRE -1152 1040 -1152 976 WIRE -416 1072 -416 992 WIRE -368 1072 -416 1072 WIRE -256 1072 -304 1072 WIRE -160 1072 -160 992 WIRE -160 1072 -176 1072 WIRE -1280 1088 -1280 976 WIRE -1280 1088 -1424 1088 WIRE -1216 1088 -1280 1088 WIRE -160 1184 -160 1072 WIRE -160 1184 -240 1184 WIRE -32 1184 -32 1056 WIRE -32 1184 -160 1184 WIRE 48 1184 -32 1184 WIRE 176 1184 128 1184 WIRE -1152 1200 -1152 1136 WIRE -1040 1200 -1152 1200 WIRE -512 1200 -960 1200 WIRE -416 1200 -416 1072 WIRE -416 1200 -512 1200 WIRE -304 1200 -416 1200 WIRE -208 1216 -240 1216 WIRE -208 1264 -208 1216 WIRE -1360 1280 -1408 1280 WIRE -1152 1280 -1152 1200 WIRE -1152 1280 -1296 1280 WIRE -1696 1296 -1744 1296 WIRE -1488 1296 -1488 1136 WIRE -1488 1296 -1632 1296 WIRE -1488 1376 -1488 1296 WIRE -1152 1376 -1152 1280 WIRE -1408 1472 -1408 1280 WIRE -1152 1472 -1152 1456 WIRE -1152 1472 -1408 1472 WIRE -1744 1488 -1744 1296 WIRE -1488 1488 -1488 1456 WIRE -1488 1488 -1744 1488 WIRE -1488 1504 -1488 1488 WIRE -1152 1504 -1152 1472 FLAG 224 208 0 FLAG 624 208 0 FLAG 832 160 vout FLAG -272 1168 vcc FLAG -272 1232 vee FLAG -208 1264 0 FLAG 336 464 0 FLAG 240 1184 vee FLAG -1920 560 0 FLAG -1952 960 0 FLAG -1904 832 vcc FLAG -1840 432 vcc FLAG -1488 -32 vcc FLAG -1152 -32 vcc FLAG -1904 1056 vee FLAG -1648 688 vee FLAG -1488 1504 vee FLAG -1152 1504 vee FLAG -1840 496 vee FLAG -512 1200 vg FLAG -144 128 vcc FLAG -144 192 vee FLAG 288 128 vcc FLAG 288 192 vee FLAG 688 128 vcc FLAG 688 192 vee FLAG -816 256 vcc FLAG -816 320 vee FLAG -928 336 0 FLAG -1328 -32 vtap FLAG 400 -96 vtap SYMBOL res -80 16 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R1 SYMATTR Value 10K SYMBOL res 144 16 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R2 SYMATTR Value 16K SYMBOL res 560 16 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R3 SYMATTR Value 16K SYMBOL cap 320 16 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C1 SYMATTR Value 10n SYMBOL cap 720 16 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C2 SYMATTR Value 10n SYMBOL res 176 -224 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R4 SYMATTR Value 10K SYMBOL res 176 -80 M270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R5 SYMATTR Value 82k SYMBOL cap -256 976 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C3 SYMATTR Value 1000n SYMBOL res 32 1200 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R10 SYMATTR Value 330K SYMBOL diode 176 1200 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D1 SYMATTR Value 1N914 SYMBOL res -48 960 R0 SYMATTR InstName R11 SYMATTR Value 40.2K SYMBOL OpAmps\\LT1679 -272 1200 M0 SYMATTR InstName U7 SYMBOL res 528 592 R180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R18 SYMATTR Value 10K SYMBOL res 416 432 R180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R19 SYMATTR Value 10k SYMBOL diode -16 656 M0 SYMATTR InstName D2 SYMATTR Value 1N914 SYMBOL diode 224 656 M0 SYMATTR InstName D12 SYMATTR Value 1N914 SYMBOL diode 368 656 R0 SYMATTR InstName D13 SYMATTR Value 1N914 SYMBOL diode 816 656 M0 SYMATTR InstName D14 SYMATTR Value 1N914 SYMBOL res -48 736 R0 SYMATTR InstName R13 SYMATTR Value 68k SYMBOL res 192 736 R0 SYMATTR InstName R14 SYMATTR Value 68k SYMBOL res 400 736 M0 SYMATTR InstName R15 SYMATTR Value 68k SYMBOL res 784 736 R0 SYMATTR InstName R16 SYMATTR Value 68k SYMBOL OpAmps\\opamp 448 528 R90 SYMATTR InstName U1 SYMATTR SpiceLine Aol=5Meg SYMATTR SpiceLine2 GBW=60Meg SYMBOL res -1504 1360 R0 SYMATTR InstName R17 SYMATTR Value 250 SYMBOL pnp -1552 592 M180 WINDOW 3 84 0 Left 2 SYMATTR Value 2N3906 SYMATTR InstName Q1 SYMBOL res -1504 32 R0 SYMATTR InstName R20 SYMATTR Value 150k SYMBOL npn -1216 848 R0 SYMATTR InstName Q2 SYMATTR Value 2N3904 SYMBOL Opamps\\LT1013 -1840 400 R0 SYMATTR InstName U2 SYMBOL voltage -1904 816 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V3 SYMATTR Value 15 SYMBOL voltage -1904 960 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V4 SYMATTR Value 15 SYMBOL res -1168 1360 R0 SYMATTR InstName R21 SYMATTR Value 250 SYMBOL res -1168 32 R0 SYMATTR InstName R22 SYMATTR Value 150K SYMBOL res -768 144 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R23 SYMATTR Value 20k SYMBOL res -1344 32 R0 SYMATTR InstName R24 SYMATTR Value 2.7Meg SYMBOL npn -1216 1040 R0 SYMATTR InstName Q3 SYMATTR Value 2N3904 SYMBOL npn -1424 1040 M0 SYMATTR InstName Q4 SYMATTR Value 2N3904 SYMBOL npn -1712 416 R0 SYMATTR InstName Q5 SYMATTR Value 2N3904 SYMBOL res -1664 560 R0 SYMATTR InstName R25 SYMATTR Value 5Meg SYMBOL cap -1360 1296 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName C6 SYMATTR Value 1000000n SYMBOL res -944 1184 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R26 SYMATTR Value 150K SYMBOL OpAmps\\LT1679 -144 160 R0 SYMATTR InstName U5 SYMBOL OpAmps\\LT1679 288 160 R0 SYMATTR InstName U6 SYMBOL OpAmps\\LT1679 688 160 R0 SYMATTR InstName U8 SYMBOL OpAmps\\LT1679 -816 288 R0 SYMATTR InstName U3 SYMBOL res -1680 256 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R7 SYMATTR Value 1k SYMBOL cap -1792 320 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C9 SYMATTR Value 10p SYMBOL cap -800 32 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C10 SYMATTR Value 10p SYMBOL res -112 272 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R8 SYMATTR Value 10k SYMBOL res -320 272 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R9 SYMATTR Value 560 SYMBOL cap -992 256 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C5 SYMATTR Value 1000n SYMBOL cap -608 272 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C8 SYMATTR Value 1000n SYMBOL res -272 1088 R270 WINDOW 0 32 56 VTop 2 WINDOW 3 0 56 VBottom 2 SYMATTR InstName R6 SYMATTR Value 47k SYMBOL cap -304 1056 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C4 SYMATTR Value 10000n SYMBOL diode -400 896 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D3 SYMATTR Value 1N914 SYMBOL diode -320 896 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D4 SYMATTR Value 1N914 SYMBOL diode -240 896 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName D5 SYMATTR Value 1N914 SYMBOL cap -1696 1312 R270 WINDOW 0 32 32 VTop 2 WINDOW 3 0 32 VBottom 2 SYMATTR InstName C7 SYMATTR Value 1000000n TEXT -1992 -16 Left 2 !.tran 0 10 0 1u startup TEXT -2000 -128 Left 2 !.options plotwinsize=0 numdgt=15 TEXT -2000 -72 Left 2 !.lib opamp.sub TEXT -1992 32 Left 2 !.save v(vout)

That's what your .asc file showed when I ran it.

What I actually said was the you didn't like the big capacitor. Something with that much capacitance would be electrolytic in practice - probably tantalum in my experience. I don't think that there's anything in there that warrants an apology, but I do apologise for getting the detail marginally wrong.

That's what I thought I said. Of course JM's most helpful act was to throw out four unnecessary transistors from your circuit, and neither of you produced any explanation of how the circuit worked, which I threw in with my five transistor version of the circuit. Since JM had previously taken my current mirror version and thrown out the split between the positive and negative-going halves of the correction waveform, it was a collective effort, involving quite a bit of innovation and creative destruction by all three of us.

Getting excited about who did what isn't a constructive use of our time. We did something neat, and are entitled to gloat about it.

Electrolytic capacitors don't zener. They break down. "Zener" diodes that break down at reverse voltage higher than about 5V don't break down by the Zener mechanism either - they avalanche. Electrolytic capacitors break down by other mechanisms (and I never got deep enough into electrochemistry to learn much about them).

Which is not what I actually said. I did want to produce a circuit which didn't need such a big capacitor if possible. But I do like big capacitors when there's no other way.

Oh I agree but it is you who keeps bringing it up. JM threw out more than half of your components and went from 60dB to 140dB in a simulation.

Really?

But that was a first attempt at using a current mirror to generate the correction wave-form. That he could see a way to simplify what I was doing isn't all that surprising - first attempts are rarely ripped up and redone as often as they ought to be.