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Though running it close to max bias will probably damage your hearing.

max voltage swing is 4 x bias. so 580 x 4. the amp does loose about 20 volts of voltage swing, so 600 is a nice number. same voltage the koss uses. also the rating on the pnp transistor. could cut the voltage to 550v for a bit more margin.

Wow! But just for my understanding, this is the limit after which damage to earspeakers can occur, right? I mean, so much power is really needed to drive the most demanding e-stats? Or is it thought as an exercise of pushing it to the boundaries ?

Tasty Fish and Chips, Beet Salad @ Andy's Anchor Bar

The war and treaty at the bijou in knoxville

It looks like Western Digital is having serious problems with its older SMR (Shingled Magnetic Recording) hard drives. High failure rates of Western Digital Blue and Red drives of 2-6TB have been reported: https://www.tomshardware.com/pc-components/hdds/wd-launches-investigation-into-problems-with-its-smr-hard-drives-the-same-drives-that-got-wd-sued-in-2021-now-reporting-failure-rates-due-to-fundamental-flaws

Finished it last night. Pretty good.

"15 Worst Audiophile Snake Oil Products That Break the Laws of Physics but Still Sell in 2025" https://www.headphonesty.com/2025/10/worst-snake-oil-products-break-laws-physics/

Shostakovich: Symphony No. 5 in D Minor, Op. 47 by Howard Mitchell (1959) https://album.link/trxprptjq5zr7 Example: Noise floor is a little high (hiss), but it made up for by getting very loud and being a great performance.

I was lucky enough to meet Prunella Scales around 20 years ago. She gave an acting masterclass to our local pro theatre company, Creation Theatre, that for some reason we got invited to. She was very nice, and was really tiny.

Timothy West - also a great actor of stage and screen - predeceased his wife Prunella aged 90 in late 2024. https://en.wikipedia.org/wiki/Timothy_West

Todd is kind of Analyst...

Would swapping out the rolling casters with footers improve the sound too?

Removed the grill which removed a "veil" from midrange 😆 and had to rework the crossover and physical alignment of the supertweeter, but yeah, I'm beginning to think the speaker angle was already a solved issue in the 1950's and 60's..

power supply schematic updated. amp board updated. circlotronpsupdated.pdf kgsshvcarbonv6.1c3cs - CADCAM.ZIP

Seems simmconn reads shematics. Regarding Q12, schematics and gerbers don't match, I think.

Maybe I didn't give them a fair shake back in the day...

I was just pointing out, as how Q12 is connected today, it’s not doing what it is supposed to do. The output should be connected to gate instead. I remember last time you recommended TTC004B as a replacement for the PZTA42 (different package). We just need something with a flat hfe-Ic curve to, say >100ma at VCE=10V.

q12 is the current limit. so if the amp board shorts, at least the power supply will not explode. what do you want me to replace the pzta part with? remember 20+ma

Q12 in the PSU seems full-on and not doing much if anything. I noticed that the 2N3904-based current limiter is not there. Many people say it is too slow, not realizing that it is protecting the passing SiCFET at every power up, before the opto coupler soft start switch is released. On the other hand, if the SiCFET decides to give up, nothing can hold it back anyways. The 2N3904-based current limiter should not be the one to blame. The amp section still uses PZTA42 despite the linearity issue we found earlier and better options are available. The STN9360 although is specified with a 600V VCEO, its curve shows onset of breakdown at a lower voltage. I didn’t take a picture with the STN9360, but the one below is similar. Technically the breakdown voltage is specified at point A, but you wouldn’t want to operate the part at point B, even though that’s still “within spec”.

I might have posted before, but if you want over 20 hours of analysis of a single album, there is:

^^ Very sad. She was brilliant in FT. ... and I got to know about her condition over a decade ago and happy that she made it this long. I use to watch her canal boat program all the time. I would just ask my partner, 'Old People on a Boat?' RIP Prunella...

You are a good man, Todd! 👍