TI degrading specs of existing parts without changing part numbers

My point, which I didn't make very clearly, is that even on 140-year-old recording technology it is possible to hear the degradation caused by the mp3 format.

Jan Panteltje snipped-for-privacy@comet.invalid schreef: |------------------------------------------------------------------------------------------| |"Have you ever used 'sox' in Linux? | |[. . .] | | If you need an interactive, graphical audio editor, use audacity(1)." | |------------------------------------------------------------------------------------------|

Alas a good TV program had cursing, so I considered using SoX to edit out cursing. Instead I actually used Audacity to produce this nice version:

grep sox backed_up_shell_histories/bash_history_timestamped_2024-08-21_14:20_backed_up_by_Process3350046_on_2024-08-21_14:32 man -k sox info sox mkdir sox mv video-swear-jar/La_Eile____.webm sox cd sox sox info sox info sox

I use MPEG-4 files but I do not get SoX to work with MPEG-4. Cf.

soxi 2025-10-23d_agallamh_le_Fiosru__2025_10_23_09_44_53.m4a soxi FAIL formats: no handler for file extension `m4a'

"2024_11_11_23_04_45.m4a is so big that Audacity needs many tens of minutes to open it.

Audacity can be used to process audio files. Alas a normal storage product is too small for Audacity to fully handle a 74-hour recording. "As a guideline, one hour of stereo recording at default settings (44.1kHz, 32-bit) occupies approximately 1.2 GB of disk space" warns

|------------------------------------------------------------------------------------------| |"[. . .] | |mediainfo (1) - command line utility to display information about audio/video files| |[. . .]" | |------------------------------------------------------------------------------------------|

Insomnia 24/7 does not have mediainfo so I requested Insomnia 24/7 to install it today. Dank u wel! (S.

The paranoia is created by the irrational market/clients.

RL

It's the program material that matters and, often, the context or venue; not the hardware.

Most distortion still from mikes, loudspeakers and other electromechanical transducers. The rest is probably in 'your' head.

RL

Clear enough to me. But that is not a 'normal' situation Long ago when Sony came out with the Umatic video recorders those had a design problem, the FM frequency discriminator for the video (luminance not audio) would in case of a tape dropout not keep the last level but treat it as a 'low frequency' causing a huge spike in the images at that point that did overdrive the electronics As time passed by with many playbacks, dropouts increased, making the tapes unwatchable. So to fix the tapes I usd an old tricK, replace the spike (easy to detect) with the video from the previous picture line

No - but it emphasises just how obvious the defects of mp3 can be.

Same problem: what to put in place of the waveform if corruption is detected. Return-to-zero works best at the higher audio frequencies but sample-and-hold works better at lower frequencies.

I solved the problem by dividing the audio spectrum into 10 bands of an octave each, then following the blanking switch with a filter tuned to the centre of that octave. The missing waveform was replaced with an approximation which was already synchronised with the waveform and at about the right frequency. The substitution is almost inaudible unless the damge is a substantial proportion of the waveform.

Exactly. The idea of an "Audio Op Amp", as though the actual requirements were special, is pretty silly.

(The idea that an 18-nV TL074 is a "low noise" amplifier is even sillier--it's a good 20 dB off the pace.)

Cheers

Phil Hobbs

Jan Panteltje snipped-for-privacy@comet.invalid schreef: |--------------------------------------------------------------------------------------------| |"mediainfo (1) - command line utility to display information about audio/video files"| |--------------------------------------------------------------------------------------------|

So, Insomnia 24/7 installed mediainfo for me which is an interesting alternative to ffprobe but the manpage for mediainfo does not explain a subset of its outputs which it showed me, so maybe I shall need to download its source instead of only using a packaged binary.

I ran mediainfo and ffprobe on different types of MPEG-4 files in

ffprobe 2025-10-23d_agallamh_le_Fiosru__2025_10_23_09_44_53.m4a ffprobe version 5.1.9-0+deb12u1 Copyright (c) 2007-2026 the FFmpeg developers built with gcc 12 (Debian 12.2.0-14+deb12u1) configuration: --prefix=/usr --extra-version=0+deb12u1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librist --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --disable-sndio --enable-libjxl --enable-pocketsphinx --enable-librsvg --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-libplacebo --enable-librav1e --enable-shared libavutil 57. 28.100 / 57. 28.100 libavcodec 59. 37.100 / 59. 37.100 libavformat 59. 27.100 / 59. 27.100 libavdevice 59. 7.100 / 59. 7.100 libavfilter 8. 44.100 / 8. 44.100 libswscale 6. 7.100 / 6. 7.100 libswresample 4. 7.100 / 4. 7.100 libpostproc 56. 6.100 / 56. 6.100 [mov,mp4,m4a,3gp,3g2,mj2 @ 0x556d78722ac0] moov atom not found

mediainfo 2025-10-23d_agallamh_le_Fiosru__2025_10_23_09_44_53.m4a General Complete name :

Example playable versions are

ffprobe 2025-10-23d_agallamh_le_Fiosru__2025_10_23_09_44_53_unload_mdat.M4A ffprobe version 5.1.9-0+deb12u1 Copyright (c) 2007-2026 the FFmpeg developers built with gcc 12 (Debian 12.2.0-14+deb12u1) configuration: --prefix=/usr --extra-version=0+deb12u1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librist --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --disable-sndio --enable-libjxl --enable-pocketsphinx --enable-librsvg --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-libplacebo --enable-librav1e --enable-shared libavutil 57. 28.100 / 57. 28.100 libavcodec 59. 37.100 / 59. 37.100 libavformat 59. 27.100 / 59. 27.100 libavdevice 59. 7.100 / 59. 7.100 libavfilter 8. 44.100 / 8. 44.100 libswscale 6. 7.100 / 6. 7.100 libswresample 4. 7.100 / 4. 7.100 libpostproc 56. 6.100 / 56. 6.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '2025-10-23d_agallamh_le_Fiosru__2025_10_23_09_44_53_unload_mdat.M4A': Metadata: major_brand : M4A minor_version : 512 compatible_brands: M4A isomiso2 encoder : Lavf61.7.100 Duration: 04:23:09.83, start: 0.000000, bitrate: 128 kb/s Stream #0:0[0x1](und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 126 kb/s (default) Metadata: handler_name : SoundHandler vendor_id : [0][0][0][0]

mediainfo 2025-10-23d_agallamh_le_Fiosru__2025_10_23_09_44_53_unload_mdat.M4A General Complete name :

Audio ID : 1 Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Codec ID : mp4a-40-2 Duration : 4 h 23 min Source duration : 4 h 23 min Bit rate mode : Variable Bit rate : 127 kb/s Maximum bit rate : 128 kb/s Channel(s) : 2 channels Channel layout : L R Sampling rate : 44.1 kHz Frame rate : 43.066 FPS (1024 SPF) Compression mode : Lossy Stream size : 238 MiB (99%) Source stream size : 238 MiB (99%) Default : Yes Alternate group : 1

We can expect Microsoft to also mess up. MS Voice Recorder finishes a playable file after hours of recording without being ordered to stop, then it produces a new file which fails to be played. E.g.

ffprobe 2026-04-11f_talk_with_Psychologist_Barbara_Alves_Nobre.m4a ffprobe version 5.1.9-0+deb12u1 Copyright (c) 2007-2026 the FFmpeg developers built with gcc 12 (Debian 12.2.0-14+deb12u1) configuration: --prefix=/usr --extra-version=0+deb12u1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librist --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --disable-sndio --enable-libjxl --enable-pocketsphinx --enable-librsvg --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-libplacebo --enable-librav1e --enable-shared libavutil 57. 28.100 / 57. 28.100 libavcodec 59. 37.100 / 59. 37.100 libavformat 59. 27.100 / 59. 27.100 libavdevice 59. 7.100 / 59. 7.100 libavfilter 8. 44.100 / 8. 44.100 libswscale 6. 7.100 / 6. 7.100 libswresample 4. 7.100 / 4. 7.100 libpostproc 56. 6.100 / 56. 6.100 [aac @ 0x561dd39daac0] Estimating duration from bitrate, this may be inaccurate Input #0, aac, from '2026-04-11f_talk_with_Psychologist_Barbara_Alves_Nobre.m4a': Duration: 03:11:03.51, bitrate: 162 kb/s Stream #0:0: Audio: aac (LC), 48000 Hz, stereo, fltp, 162 kb/s

mediainfo 2026-04-11f_talk_with_Psychologist_Barbara_Alves_Nobre.m4a General Complete name :

Audio Format : AAC LC Format/Info : Advanced Audio Codec Low Complexity Format version : Version 4 Codec ID : 2 Bit rate mode : Variable Channel(s) : 2 channels Channel layout : L R Sampling rate : 48.0 kHz Frame rate : 46.875 FPS (1024 SPF) Compression mode : Lossy Stream size : 222 MiB (100%)

ffprobe 2026-04-11g_MS_Voice_Recorder_made_this_file_which_players_fail_to_play__talk_with_Psychologist_Barbara_Alves_Nobre.m4a ffprobe version 5.1.9-0+deb12u1 Copyright (c) 2007-2026 the FFmpeg developers built with gcc 12 (Debian 12.2.0-14+deb12u1) configuration: --prefix=/usr --extra-version=0+deb12u1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libglslang --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librist --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --disable-sndio --enable-libjxl --enable-pocketsphinx --enable-librsvg --enable-libmfx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-libplacebo --enable-librav1e --enable-shared libavutil 57. 28.100 / 57. 28.100 libavcodec 59. 37.100 / 59. 37.100 libavformat 59. 27.100 / 59. 27.100 libavdevice 59. 7.100 / 59. 7.100 libavfilter 8. 44.100 / 8. 44.100 libswscale 6. 7.100 / 6. 7.100 libswresample 4. 7.100 / 4. 7.100 libpostproc 56. 6.100 / 56. 6.100 [mov,mp4,m4a,3gp,3g2,mj2 @ 0x5616cf40fac0] moov atom not found

mediainfo 2026-04-11g_MS_Voice_Recorder_made_this_file_which_players_fail_to_play__talk_with_Psychologist_Barbara_Alves_Nobre.m4a General Complete name : 2026-04-11g_MS_Voice_Recorder_made_this_file_which_players_fail_to_play__talk_with_Psychologist_Barbara_Alves_Nobre.m4a Format : MPEG-4 Format profile : Base Media / Version 2 Codec ID : mp42 (mp41/isom) File size : 25.3 MiB

(S.

There should be a legally binding definition of "high speed" too.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

John Larkin snipped-for-privacy@Glen--Canyon.com wrote: |-------------------------------------------------------------------| |"There should be a legally binding definition of "high speed" too."| |-------------------------------------------------------------------|

The fastest integrated circuits are by no hardware description language, whereas VHDL stands for Very-High-Speed-Integrated-Circuit Description Language. (S.

To their dying day, National maintained that 1 mV was “low offset“ and 400 ns was “fast settling.”

Cheers

Phil Hobbs

Does that mean you talk fast?

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Absolutamente. It falls under the category "Don't do this!".

Quite normal for market-successful components.

My longest-running design is from 1994 and still in production with all the same semiconductors. It might still be in production when I head home to Jesus.

A former co-worker had a Chevy truck from the mid 50's. One day around the year 2000 it suffered minor indigestion, starter was bad. He asked me if I could give him a lift to an auto parts store. "Did you call them to see if they have a starter for such an old truck?" ... "Nah, don't need to, those are still made and they've always got them". Sure enough they did and he swapped it out during lunch break. Still had enough time for lunch.

The worst I ever saw: A MOSFET that was used in a mixed supply situation. It switched a 3.3V rail but the gate control came from

Yikes. Protected gates usually zener at 20 volts or so.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

More than a process change, it is a whole different product. Old was NPN input stage, new is PNP inputs. Unforgivable to not amend the part number in any way.

You'd better not buy TI parts any more.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

Exactly!

They were rarely anybody's first choice. Even when they came up with something neat they'd leave out a vital detail in the data sheet. They introduced a really nice MOSFET input op-amp and failed to mention in the data sheet that it had about 10pF input capacitance. For once I'd almost got a printed circuit layout that worked first time, but I had to bodge in 2.2pF capacitor in parallel with the feedback resistor to kill the oscillation the 10pF produced.