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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?

Some if not all 6dj8/ecc88 datasheet has spec'ed max plate voltage at 130V, which the top tubes operate right around that range, I'd think e88cc/6922 is actually safer bet.

yes ecc88, e88cc and 6922 can all be used. I believe the e88cc is similar to a 6922 - which is what I have been using in the T2 for years.

Is it possible to use E88CC instead of ECC88 in this T2? They have similar ratings but also some differences.

I “finally” upgraded my espresso grinder. Niche Duo with SSP MP. I wouldn’t say my espresso tastes any different, but the Niche Zero will sell on eBay fine. Pour over is greatly improved over the Niche Zero. Makes it worth it. Especially since the Zero will sell fine.

I got to handle a GFX100RF. It convinced me to buy one. I don’t know if I’ll keep my Q once it arrives. It’s brilliant, though. I got to handle a Hassy 907/100C, and it was cool, but very fiddly and fragile feeling. I bought a Nikon 810 with a 58 f/1.4 as well, in mint condition. I should be good on replacing my film photography.

Decided to have a go at Chicken Korma. Bites while seasoning were pretty great. Naan is staying warm in the oven to go alongside.

I just got a colnago c50 with super record 11, but no pictures until Christmas because it’s under the proverbial tree.

Starting to look the part!

Got a ride with the ANG two weeks ago to check out our remote project site in what southerners call Northern Maine (Bangor area). They had an issue with the first aircraft, but thankfully had a spare, and the delayed departure made for a convenient return time.

Violin repair:

Glad that you got to see Colin.

Had dinner with @cetoole and @MexicanDragon, who graciously drove out to meet me in Lake Forest Park. I am also convinced Seattle is entirely too cold for me. Get me back to sunny California!

A bit of minimalist droney piano stuff. Quite lovely if you like that sort of thing. https://vantzou-harrison-bennett.bandcamp.com/album/christina-vantzou-michael-harrison-and-john-also-bennett

Finally the PCB's arrived for the Kiwi Ears headphone drivers: Just three different PCB's needed, on the left is the diaphragm ring which is a 0.6mm pcb but with no solder mask so it is actually 0.51mm. This has to be ENIG to make it completely flat but most fabs require that anyway. Film is 2um mylar-c as that is so simple to get and relatively easy to work with. In the middle is the dust cover holder/spacer. I made this 1.6mm thick as that way it clears the stock lip on the baffle that was around the dynamic driver. I used the first one as spacer and then stacked up the driver sandwich. For the dust covers I used the same mylar as the diaphragms but not stretched as much Finally the stators, 1mm ENIG pcb's and this is the outer side with the inner side having a smaller active area, aka like the SR-007. Holes are a bit less than 1mm but that can easily be altered for another run. Here they are assembled with the only alterations to the baffle where I counter sunk the mounting screws. There were just the three holes there in a row and with the earpad mounting plate being flush to this, it had to be done. One second with a counter sunk bit will do this as this is nasty, cheap ABS plastic. Here they are assembled. Only mods to the chassis is that I enlarged the two holes there are on each side (cable entry and a port on top) to 5mm so the strain relief would fit and the solid plastic plug I glued into where the port is. The cable is the 6 core silicone wire that can be found everywhere now with a 3D printed Y-split and Stax plug made from an XLR plug and pins. Now for the sound... lets just call it work in progress. This is very much the first draft and one channel is slightly weaker than the other (I swapped out the diaphragm for another which fixed it mostly) so I need to look into that. I'll probably just build a second pair of drivers so I can match them into pairs as I have another set of the headphones. Massive baffle leak too and the housing... has issues... so bass is not their strong suit for now. That needs to be fixed but I might have to get creative with that. Still for a cheap project that took only a few hours to make and cost less than 150$ all in... there are worse ways to spend an afternoon.