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Looking good, that reminds me of my old helmet (mec manta), what is it?

I don’t see how the bias servo could have worked. You have the + input of the opamp connected to the amp output terminal, which means the integrator has a dancing reference that it has no rejection of. Furthermore, a divided down version of that amp output signal is shared with other servos, an interesting way to create crosstalk?

i looked at the ltspice file for a bit. best guess is that there is something wrong with the jfet model that causes issues. replace the fets with bipolar and see if it works right. the reason all the darlington transistors are on the heatsink is so they can thermally track. effects thd. another thing that really effects the thd is the power supply rails. anything under +/-20v is too low and causes much higher distortion. +/-30v is the sweet spot. and once you do that, you end up with an amplifier that is a lot more than 5 watts. in your second schematic, you have taken out the low impedance load on the output of the current mirrors. lots more voltage gain resulting in required high amounts of feedback. definitely not the original design goals. if you want lots of open loop gain, probably best to pick a different design. as far as the bias servo, would have to see thd with and without it.

whatevs...

For what it's worth jury still out here too and much of that depends, of course, on what the eventual payoff is. I probably have a different relationship to sci-fi, and first episode isn't my favorite, but some of the theories out there* about what the show is truly about, takes me back all the way to weekly discussions during Twin Peaks' initial run (which may have never been resolved). Certainly feels like what Severance seemed to be for others and wasn't for me. A lot of this is trust, as you implied, with Vince. . . . . . * spoilers kinda . One of the theories, unlikely, but interestingly, is it's about individual (warts & all) love versus universal love. . . . . . spoilers likely . Another is that there are not only two teams in play.

Loot... It's such a funny show. Like Arrested Development level. So good.

Game went so well. One of the kids couldn't make it, so I played the big guy. Really leaned in to his 9 INT, named him Tonk, spoke in third person. At the end they found a Deck of Many Things and everyone drew 1-2 cards (I had removed the game ending ones)... Tonk got 'avoid a tragic event from your past' and suddenly his INT shot up to 15 and his manner completely changed (basically just made him me), the kids loved it. My son was definately MVP, being a 3rd lvl fighter dual wielding light Katana with Elemental mastery and 30ft of reach was devastating. He basically got all the HDYWTDT's as he one shotted all the bosses, was a complete riot. 🙂 Any suggestions on Tonks 'educated' full name? Maybe something like Tonculis Reginald Fairweather III? 😄

Thanks @JoaMat, this data is really helpful. From your measurement it does look like I really needed either bias servo or do it like the original for hopefully less drift. Nice soft start behavior too

Gordon Murray (designer of the McLaren F1) modifies cars - his Alfa Romeo Junior Z from Alfaholics:

Hehe, I don't think I'll ever be there but I have a lot of fun messing with this stuff. I might open this up as a DIY project if anybody is interested as this isn't all that hard to do and no bad chemicals are used. While on the subject, I finally got the last parts to get my reclaimed SR-009 drivers up and running with new diaphragms and dust covers. I skipped straight to the Mk2 version of the main diaphragm rings and they are now sitting on my head with nothing holding the earpads on them and cables just dangling off. I keep reiterating the new cable entry design so I won't post pics until the system is all complete.

Jesus, what a WIN! Where's the waiting list for the production run? 🤩

I’ve a smd version of CFA3. Only output transistors on heat sink. Bias is servo controlled. Works all right. Output stage with servo looks like this…

Great. My build is proceeding slowly but well under the safe supervision of MLA. Four Mullard E88CC lie waiting in the box.

Jury is still out on Pluribus for me. I trust Vince, so I’ll stick with it, but outside of that first episode it hasn’t really captured my interest… at least not yet. First part of the final Stranger Things season leaves me likewise cold. I feel like maybe I should have rewatched things to get caught up again? I feel lost and disengaged.

So I have spent the thanksgiving break playing around with ltspice, mainly wanted to do a 3-5W class A into 32 ohm balanced amp and started off with Kevin's CFA2/CFA3 design, and comes down to something like this, basically a slightly reduced CFA2: Just thought I want to put here for some input before trying to actually make it, which I'd much appreciate if any 🙂 I mainly have questions around: "floating tail" input (just like uberamp/preamp2025 input) instead of separate CCS (like dynalo/CFA3 input): Works in sim but in reality I don't know if I can just send feedback this way and make it fully differential with CF. When input is single ended where one side is ground, due to the feedback it seems to be amplifying the voltage disproportionally on two sides while overall differential gain is maintained. A problem or just an expected behavior that I can live with? (most of time I won't use single ended input) thermal: Is it essential to mount all the transistors in darlington triples to heatsink? Dissipation wise the inner ones don't really run all that hot. Im tempted to just mount the output pairs, planning to run them at around 200mA each phase margin: unsure if I'm measuring open loop gain correctly, am just doing vout / (vin - vfb) on one leg, where vfb is the feedback entry point. other suggestions?

Just a bit of nerd fun.

Such a nice touch on the piano. A well-chosen mix of works.

Yeah, I was just going to mention, I remember all the stories from Steve Hoffman about having to cook the tapes so they could at least be run through the player. Movies also have all their own issues.

I found another article covering the tape degradation: https://www.headphonesty.com/2025/11/worlds-important-master-tapes-lost-experts-warn/

I’ve been freezing my beans at three weeks post roast for years. Works great!

Sapphire Sandwich arrived. I neglected to make sure the stock bracelet had enough links, so it’s a good thing I had a Forstner Flat Link (which was a bear to size) ready to go. I’m very happy with it.

The ‘Race Against Time’ to Save Music Legends’ Decaying Tapes https://www.nytimes.com/2025/12/01/arts/music/iron-mountain-audio-tape-preservation.html?unlocked_article_code=1.5U8.T2jL.WEmPfaX9fX5G&smid=nytcore-ios-share (Gift article)

Newb question: I just bought 10 lbs. of coffee (enough to last me a year). What's the best way to store it? Hermetically sealed, frozen, or other?