Today, after a particularly geeky argument with a coworker, I loaded up an AAC encoded audio file and realized, for the very first time, that lossy audio compression is actually Good Enough. Perhaps it's because a part of me is still stuck in 1999, but I honestly didn't think that lossy compression of any kind would bother keeping frequencies above ~18 KHz. Yet, here it is stretching all the way to 23KHz:

This must mean that AAC is perceptually transparent right? I mean, I doubt that even the 44.1 KHz PCM source would contain much, if any, information above 22 KHz. By the way, this particular song was purchased from iTunes back in 2017. Foobar shows bit rates ranging from 210 to 366 kbps, generally hovering around the 275 mark.

pan069 wrote on 2023-07-04, 20:38:

Is it not the jumpered 2 pin header next to TB LED? I.e. with the jumper on the header turbo is always on. Difficult to see from the photo. What happens if you remove that jumper?

I did try that one, because usually the turbo switch is very close to the turbo LED, but nothing happened. I didn't want to press my luck and risking damaging the board, so I've placed it back as soon as I saw that nothing happened. This motherboard won't be in my permanent builds, so I'm satisfied that at least I can activate/deactivate turbo by keyboard.

Standard Def Steve wrote on 2023-07-05, 04:38:

Today, after a particularly geeky argument with a coworker, I loaded up an AAC encoded audio file and realized, for the very fir […]
Show full quote

Today, after a particularly geeky argument with a coworker, I loaded up an AAC encoded audio file and realized, for the very first time, that lossy audio compression is actually Good Enough. Perhaps it's because a part of me is still stuck in 1999, but I honestly didn't think that lossy compression of any kind would bother keeping frequencies above ~18 KHz. Yet, here it is stretching all the way to 23KHz:

This must mean that AAC is perceptually transparent right? I mean, I doubt that even the 44.1 KHz PCM source would contain much, if any, information above 22 KHz. By the way, this particular song was purchased from iTunes back in 2017. Foobar shows bit rates ranging from 210 to 366 kbps, generally hovering around the 275 mark.

I would say yes. Hi-Fi guys will soon lynch you and me both for not listening to a real LP though. 🙄

appiah4 wrote on 2023-07-05, 06:13:

Standard Def Steve wrote on 2023-07-05, 04:38:

Today, after a particularly geeky argument with a coworker, I loaded up an AAC encoded audio file and realized, for the very fir […]
Show full quote

Today, after a particularly geeky argument with a coworker, I loaded up an AAC encoded audio file and realized, for the very first time, that lossy audio compression is actually Good Enough. Perhaps it's because a part of me is still stuck in 1999, but I honestly didn't think that lossy compression of any kind would bother keeping frequencies above ~18 KHz. Yet, here it is stretching all the way to 23KHz:

This must mean that AAC is perceptually transparent right? I mean, I doubt that even the 44.1 KHz PCM source would contain much, if any, information above 22 KHz. By the way, this particular song was purchased from iTunes back in 2017. Foobar shows bit rates ranging from 210 to 366 kbps, generally hovering around the 275 mark.

I would say yes. Hi-Fi guys will soon lynch you and me both for not listening to a real LP though. 🙄

On a good setup, with album materials I am deeply familiar with I can tell the difference between MP3/AAC and CD quality audio. The vast majority of situations between humans and their music will see no improvement from High Res audio. I collect cassettes because I feel like the subtle defects that format introduces can enhance the listening experience for certain genre (grunge, 80s and 90s rock, alternative, etc). 99 percent of vinyl nuts and tape heads are running with garbage equipment that hasn't been serviced or calibrated in decades though and aren't even getting the most out of the media they are enjoying, and those people honestly would be served better by a CD copy of the same album. When it comes to hardware the biggest two are the method of amplification and the speakers/headphones. I have some Kenwoods out in my garage that I got at a thrift store for $2 and refoamed that sound better than 90 percent of new, "audiophile" speakers. They cost $555 in 1972 but nobody cares about them because they aren't one of 10 specific models the "hifi community" has decided are the best. Hell, I don't even have a particularly great amp hooked up to them, I have them running off a mid 1980s Pioneer SX series receiver. For analytical music listening I usually prefer my PC which is a Soundblaster Z (with built in 600ohms headphone amp) and a pair of JVC HARX-900 headphones, I use an EQ curve that I feel like gives a spacious feeling to the audio coming out of the headphones.

What's far more important is the mastering done in the studio. The clearest example of this is the normal master of "In Utero" by Nirvana compared to the MFSL mix of it.

Listen to this:

Official Deluxe Edition Remaster: https://www.youtube.com/watch?v=AVnCuW3nkns
Mobile Fidelty Sound Labs Remaster: https://www.youtube.com/watch?v=QiG1XhxIIcY

Listen to how much more separation there is between the guitar and Kurts voice in the intro, and how much more impactful the drum beat is when it erupts out of the background. That entire album from MFSL is a highlight of what a well done remaster can do to an album. No amount of hifi gear will save a bad master, and 90 percent of these premium new press vinyl you see are just FLAC files pressed to vinyl, the only vinyl I even consider is either original copies or AAA mastering (Analog recording, analog mixing, analog media) because otherwise you might as well get the digital copy and cut out the analog middle men. The goal should be to get as close the original master recording in as few steps as possible. When you get a MoFi release your getting either a 1st or 2nd gen master tape transfer that is converted to a ludicrously high bitrate DSD stream (several times what consumer hardware does in that format) mastered, and then either down converted to DSD 1.2 for SACD releases or direct lathe mastered for vinyl. Seeing as how its already gone digital for the remastering process you might as well get the SACD.

This has been a rant about HiFi audio, thanks for reading.

Audio fools are a special breed. If you whisper "oxygen free copper" in their ear, they are likely to need a change of pants.

Don't get me wrong, I have a couple sennheiser headsets, and im likely to buy from them again, but the path of "reliable, high quality, high performance " to "marketing buzzword circle jerk" seems to trap a lot of people with more money than sense.

TheAbandonwareGuy wrote on 2023-07-05, 06:38:

On a good setup, with album materials I am deeply familiar with I can tell the difference between MP3/AAC and CD quality audio. […]
Show full quote

On a good setup, with album materials I am deeply familiar with I can tell the difference between MP3/AAC and CD quality audio. The vast majority of situations between humans and their music will see no improvement from High Res audio. I collect cassettes because I feel like the subtle defects that format introduces can enhance the listening experience for certain genre (grunge, 80s and 90s rock, alternative, etc). 99 percent of vinyl nuts and tape heads are running with garbage equipment that hasn't been serviced or calibrated in decades though and aren't even getting the most out of the media they are enjoying, and those people honestly would be served better by a CD copy of the same album. When it comes to hardware the biggest two are the method of amplification and the speakers/headphones. I have some Kenwoods out in my garage that I got at a thrift store for $2 and refoamed that sound better than 90 percent of new, "audiophile" speakers. They cost $555 in 1972 but nobody cares about them because they aren't one of 10 specific models the "hifi community" has decided are the best. Hell, I don't even have a particularly great amp hooked up to them, I have them running off a mid 1980s Pioneer SX series receiver. For analytical music listening I usually prefer my PC which is a Soundblaster Z (with built in 600ohms headphone amp) and a pair of JVC HARX-900 headphones, I use an EQ curve that I feel like gives a spacious feeling to the audio coming out of the headphones.

What's far more important is the mastering done in the studio. The clearest example of this is the normal master of "In Utero" by Nirvana compared to the MFSL mix of it.

Listen to this:

Official Deluxe Edition Remaster: https://www.youtube.com/watch?v=AVnCuW3nkns
Mobile Fidelty Sound Labs Remaster: https://www.youtube.com/watch?v=QiG1XhxIIcY

Listen to how much more separation there is between the guitar and Kurts voice in the intro, and how much more impactful the drum beat is when it erupts out of the background. That entire album from MFSL is a highlight of what a well done remaster can do to an album. No amount of hifi gear will save a bad master, and 90 percent of these premium new press vinyl you see are just FLAC files pressed to vinyl, the only vinyl I even consider is either original copies or AAA mastering (Analog recording, analog mixing, analog media) because otherwise you might as well get the digital copy and cut out the analog middle men. The goal should be to get as close the original master recording in as few steps as possible. When you get a MoFi release your getting either a 1st or 2nd gen master tape transfer that is converted to a ludicrously high bitrate DSD stream (several times what consumer hardware does in that format) mastered, and then either down converted to DSD 1.2 for SACD releases or direct lathe mastered for vinyl. Seeing as how its already gone digital for the remastering process you might as well get the SACD.

This has been a rant about HiFi audio, thanks for reading.

I aree with a lot of this. I use refurbished AR-7 stereo speakrs from 1978 and they sound amazingly natural compared to anything modern I listen to - my ears just reject modern hifi speakers..

Also, mastering/mixing is indeed incredibly important and the industry's dumbass quest to achieve the loudest album has basically ruined even good recordings with pointless remasters.

Me audio caveman, me no hear better sound above 120kbit/44khz MP3, if sound crappy, then same crappy on CD it came from. Me notice most in Bach pieces when multiple high voices artifact, me don't find that situation on a lot of other music. Me like Koss and 20th century Sears audio equipment. Me think bullshit/sound/price ratio best there. Me like save space, me get pissed when audiobook come in 320kb lossless mammoth size, why not more like gazelle? Mammoth not speak clearer, voice not big for mammoth to carry. Not like keep mammoth for tiny thing he carry.

Same with laptops. If the speakers don't say HK or B&O, it's crap.
Remember when some laptop manufacturers came with integrated subs? Ha!

The rotating platter next to it isn't going to like that very much. Luckily the 'sub' didn't came below 100Hz or so.

This is Vogons. People seem to be quite contend with PC Speaker sound and/or 8-bit mono audio at 23 kHz (what the original Sound Blaster provided) with quite noisy output on machines whose CPU can‘t even decode MP3-encoded audio in realtime.

With that said, for people just slightly interested in digital audio and video encoding, I highly recommend „A Digital Media Primer For Geeks“ by Monty of xiph.org, available on YouTube.

Thermalwrong wrote on 2023-07-03, 02:10:

And it's behaving on the breadboard now with an Atmega8A, this is getting transferred to a stripboard PCB tomorrow. Kinda funny, the bugs I had to track down were each caused by my trying to make the variables more efficient (changing int values to bytes)
TurboDisplay-Breadboard.jpg

Now it's finished, but not without a tragedy in the process.

This 486-in-a-Desktop-MATX case doesn't have enough molex plugs, and it runs a doubler off of one. I plugged in a molex > fan adapter that I'd modified ages ago for running at 5v - making it so that it could be plugged in backwards...

I didn't look closely enough when hooking everything back up. 12 volts went into where 5 volts should go and now my Mitsumi FX400 CD-rom drive has gone pop, the atmega8a microcontroller that was doing the display, is no more. 🙁

The atmega8a chip I'm not sad about, I had 2 of them and bought them before the component shortage really took hold, so they were cheap. The remaining one now runs the turbo display. It does mean there's not one left to run the 386 turbo display though.

For the CD-rom drive, I really fried that poor thing. If given power now it's just randomly running motors and can't eject, there's a big hole in one of the chips on the drive's main PCB. I'm glad it didn't do more damage to the computer than just these 2 things.
I Was looking online to see if there would be a similar drive for parts or something, or a similar 4x CD-ROM drive, but then I checked my available 'stock' and it turns out I actually have 2x CRMC-FX400 drives from junk lots over the last few years.
The one I burned was the FX400B and the spare is an FX400D. The bezel is nicer on the one I just destroyed and the manual eject is broken, so figuring out how to swap the bezel over was tricky. I found the eject motor wires and hooked the bench PSU up to get that to eject. Now I've got 1x good Mitsumi 4 speed CD-rom which is working perfectly.
Maybe the dead one's laser mechanism could be useful in future? Or I'll find another busted drive to make one more good one.

This drive bay that adds all the bits that ATX doesn't include has made this PC build so much more usable. Now there's a front rocker switch to turn the PSU on/off, hooked to the AT > ATX cable adapter. Instead of relying on the switch on the back of the PSU.

Added a hook-up point for another LED to run the Power LED since I thought the motherboard doesn't have one (the Soyo 025R2 does actually, apparently have one, shared with the keylock)
The compact flash slot is moved to the extra slot at the back in the ATX backplate 3d-print, since that was blocking the fan.

I've really gotta re-design the 3d printed ATX backplate part to work better, I can see a bunch of things to improve there now.

Since this computer is much easier to use now, I've been benching it and doing some testing. It really hates running those EDO 72-pin SIMMs I modified to run as FPM and now it's got some regular RAM. One RAM slot is falling apart, but 8MB is enough for now. Can't seem to reduce RAM wait states and reducing cache timings at all doesn't want to work. Might need to give this thing some more/better SRAM.
It used to have an AMD 486 DX4 100 in it and running one of the *V8T 486 chips the performance was a little disappointing, not being quicker than 1:1 realtics in doom as a quick benchmark.

Put another AMD 486 DX4-100 in it, but this time one with the part code ending in *8B for write-back. The Soyo 025R2 manual shows how to set up the Intel write-back chips but only does CPU examples rather than saying what each jumper does, no reference to AMD write-back chips.
I decided to find which jumper pin connected to the WB/WT pin in the socket (this page is the top-view layout). That little red jumper is where I worked it out to be for the WB/WT pin.

Can't believe this either, after the earlier burnt stuff I've now put the CPU in rotated 90 degrees after checking the socket pins, I couldn't see the pin1 notch with the heatsink fitted.
I got lucky this time and it was rotated the way where most of the VCC/GND pins still match up. The system boots now the CPU is back in the right way and with the jumper fitted, Write-back is now selectable in the BIOS and it's faster than 1:1 realtics in doom 😁 Overclocked it to 120MHz and now it's even better.
I might put the top back on this thing and put it away working, much safer that way.

thp wrote on 2023-07-05, 20:01:

This is Vogons. People seem to be quite contend with PC Speaker sound ....

I used to have a 4" Wharfdale cone out of a 1960s radio, man that was the best PC Speaker sound 🤣 (Semi serious, it doesn't improve any if you go too big, I think that 4" size is the sweet spot, I haven't managed to find anything sounds quite as good since)

appiah4 wrote on 2023-07-05, 06:13:

Standard Def Steve wrote on 2023-07-05, 04:38:

Today, after a particularly geeky argument with a coworker, I loaded up an AAC encoded audio file and realized, for the very fir […]
Show full quote

Today, after a particularly geeky argument with a coworker, I loaded up an AAC encoded audio file and realized, for the very first time, that lossy audio compression is actually Good Enough. Perhaps it's because a part of me is still stuck in 1999, but I honestly didn't think that lossy compression of any kind would bother keeping frequencies above ~18 KHz. Yet, here it is stretching all the way to 23KHz:

This must mean that AAC is perceptually transparent right? I mean, I doubt that even the 44.1 KHz PCM source would contain much, if any, information above 22 KHz. By the way, this particular song was purchased from iTunes back in 2017. Foobar shows bit rates ranging from 210 to 366 kbps, generally hovering around the 275 mark.

I would say yes. Hi-Fi guys will soon lynch you and me both for not listening to a real LP though. 🙄

I remember when my Dad brought home a LaserDisc player in the early '90s. We primarily used it to play CDs, but would occasionally rent movies on LD too.

I would've been around 12 or 13 at the time, and CD audio just blew my mind. Hearing that crystal clear treble that was painfully missing from all of my tapes for the first time, I practically passed out from pleasure. I know there are some folks out there who insist that CDs sound clinical, excessively bright, and perhaps even a bit too digital, but after spending the first 12 years of my life listening to worn out tapes and records, I was instantly hooked. I spent most of my allowance repurchasing favourite albums on CD, and would just spend hours rediscovering them.

Dad had a fairly decent setup. I remember there being a mid-70s Pioneer amp, Yamaha tape deck, Sony turntable and VHS, and I *think* Infinity speakers? But my family absolutely loved listening to music together, so a lot of our records and cassettes were just worn to hell. The shiny new CDs really let that old system sing!

I could never go back to records. I get it, some people really like the 'analog warmth' of the format, but I was so eager to get away from that ancient tech that I don't ever see myself rebuilding a once huge vinyl record collection.

Still messing with computers. I am pretty much done recording #SEPTandy content, and have been working on some #DOSCember stuff now. I just recorded a BUNCH of footage off the NanTan Notebook FMAK9200D of Sim City (I finally fixed the garbled text - it was TSRFONT.COM was needed - apparently it needs a special TSR to fix the messed up fonts in DOS).

I also FINALLY found a way to write to my vintage DDO'd HDDs from a Virtual Machine using Windows 2000 Professional in VirtualBox. Here's how I did it...

- Install Virtualbox
- Install Windows 2000 Professional x86 SP4
- Download and Install the "Host Additions" CD from inside Virtualbox with Win2K Running
- Reboot Virtualbox
- Plug in the vintage DDO'd Drive into a USB to PATA converter, plug the converter into the USB port on the computer
- In Virtualbox, click the "devices" "USB" then select the device plugged in, the device will pop up in the host

If you're using an external USB for storage, like I am, and it's too new for Win2K, you can set it as a shared folder, set for auto mount, reboot the VM, and then drag and drop from the share to your HDD over USB in the Win2K Host. It works awesome. Basically tricked out the NanTan with all the ISOs to virtualize for Castles 2, The 7th Guest, Shivers, King's Quest V Talkie (A poooooisinous Snake! (strangles OWL)), and load on all the other stuff without having to go through a bunch of hubbaboo to enable my FTP Share over the internet and get to it tethered to my cell phone (and them remember to turn said share off afterward).

thp wrote on 2023-07-05, 20:01:

This is Vogons. People seem to be quite contend with PC Speaker sound and/or 8-bit mono audio at 23 kHz (what the original Sound Blaster provided) with quite noisy output on machines whose CPU can‘t even decode MP3-encoded audio in realtime.

I half-resent that comment. While I am fond of the old PC speaker, I do loathe unnecessary noise in audio output. 😁

Was testing a new (to me) Socket 7 motherboard today and it seemed totally dead. Other than flashing the KB lights, no signs of life, no beeps. I temporarily forgot I have a POST card, so I skipped right to popping out the BIOS and throwing it in my recently acquired EEPROM programmer. Was able to determine that it had (most of) the v1.0 BIOS for the mobo. I flashed the v1.7 BIOS on it and that did it - it now POSTs. (Guessing that re-flashing the v1.0 might have also worked but, 🤷‍♂️)

I feel like I have now leveled up slightly as a retro tech geek. ☺️

ubiq wrote on 2023-07-05, 23:59:

Was testing a new (to me) Socket 7 motherboard today and it seemed totally dead. Other than flashing the KB lights, no signs of life, no beeps. I temporarily forgot I have a POST card, so I skipped right to popping out the BIOS and throwing it in my recently acquired EEPROM programmer. Was able to determine that it had (most of) the v1.0 BIOS for the mobo. I flashed the v1.7 BIOS on it and that did it - it now POSTs. (Guessing that re-flashing the v1.0 might have also worked but, 🤷‍♂️)

I feel like I have now leveled up slightly as a retro tech geek. ☺️

Nice! It's always super satisfying solving a problem like that. 😁

Today, I made this Varta battery replacement at home, no custom PCB.

Wow. That's a beautiful work of art right there.

In any event of retro activity, I took my IBM Wheelwriter 10 Series II out of storage and started to use it again. It ran out of ribbon as I was typing a murder mystery paper and it's time to order some and correction ribbon with an access panel door that has the indicator marker window so I can see where the assembly is at.

As you can see, once I get more ribbon, I'll have to retype the papers and see if I can get about 10 pages or so done (double-sided).

Finally got around to doing the Tandymod for my IBM PCJr: https://texelec.com/product/pcjr-tandymod/

For those not familiar, this modification allows you to run programs that are specifically made for Tandy graphics, which the PCJr normally cannot run because of the differences in how it addresses the video memory (at least that is my understanding that I could be completely wrong)

Involves taking the PCJr apart and desoldering a chip and then replacing it with a socket and the modified chip. Took time and patience with a vacuum desolderer, solder wick, and a hot air station. Everything I had read about this machine, says that it is particularly easy to lift traces, but fortunately, was able to pull it off without damaging the board. Only damage was to a small plastic clip holding the motherboard in place, that instantly broke with the slightest pressure, but it is nonessential.

Pretty cool mod, and expands the library of PCJr compatible software. The machine still runs slow as nuts, but next project for this machine I want to put together a pc sprint board and try to overclock and max out the 8mhz V20 I have in there.

A sneak peek of my upcoming project 😁