WTF I love C-Media now. Seriously though, this looks really cool.

appiah4 wrote on 2022-05-08, 18:24:

I have been using this card in my daily driver retro PC (Cx5x86-120) for three days now, and this is by far, by a long long long far, the most amazing ISA sound card I ever used.

I mean, just listen to this recording. This is captured from the card's Analog Line Out using a Behringer UMC22 USB DAC. Brilliant..

Dune - Arrakeen Palace

How come one of the audio channels sounds inverted? Is this just how the Dune soundtrack is (sorry, I've not played it!).

darry wrote on 2022-05-08, 23:39:

Oh, and I have noticed that unlike every other CMI8330 or HT1869v+ based card that I have seen, this one actually has a 14.318MHz oscillator on board rather than sourcing that clock from the ISA bus. Is that a first for a card based on that chip ?

The one integrated on my PC Chips M571 motherboard has that oscillator too.

Maybe it was only the standalone CMI8330 cards that omitted it?

Gmlb256 wrote on 2022-05-08, 23:12:

Shreddoc wrote on 2022-05-08, 21:58:

appiah4 wrote on 2022-05-08, 18:24:

I have been using this card in my daily driver retro PC (Cx5x86-120) for three days now, and this is by far, by a long long long far, the most amazing ISA sound card I ever used.

I mean, just listen to this recording. This is captured from the card's Analog Line Out using a Behringer UMC22 USB DAC. Brilliant..

Dune - Arrakeen Palace

If it's not too much to ask - could we please have a comparison recording, with the same recording equipment and audio samples, but using a more mundane enthusiast ISA card (say an Audician32) ?

Without that, it's impossible (from a recording) to actually objectify how it differs from the norm.

For me all that obsession with getting the "cleanest" analog output are an audiophile thing. The most practical purpose I see for this is when using headphones.

Don't get me wrong, I would recommend that sound card considering the breath of compatibility with DOS games once it is released.

Seems like an excellent card, no doubt.

I'm just a fan of the "show, don't tell" school of marketing, which I why I requested a comparison recording from that poster. If he is kind enough to indulge, and has time.

A whole page of specs and endorsements is as nothing, compared with two simple recordings saying (for example!) "this is Common Game X; Recording1.ogg is a standard enthusiast ISA card (the Audician32), and Recording2.ogg is this new card. That massive difference you hear, is why we think this new card is awesome".

RichB93 wrote on 2022-05-09, 00:11:

WTF I love C-Media now. Seriously though, this looks really cool.

appiah4 wrote on 2022-05-08, 18:24:

I have been using this card in my daily driver retro PC (Cx5x86-120) for three days now, and this is by far, by a long long long far, the most amazing ISA sound card I ever used.

I mean, just listen to this recording. This is captured from the card's Analog Line Out using a Behringer UMC22 USB DAC. Brilliant..

Dune - Arrakeen Palace

How come one of the audio channels sounds inverted? Is this just how the Dune soundtrack is (sorry, I've not played it!).

(EDIT:I thought) I recorded with L/R inverted by mistake so manually swapped stereo channels in Audacity. AFAIK this swapped version is the correct way it should be, but if I was actually right the first time and swapped channels in error let me know and I will fix it tonight (LOL)

EDIT: Just checked and I was actually right the first time around, I will fix that tonight sorry.

Shreddoc wrote on 2022-05-09, 04:47:

Seems like an excellent card, no doubt. […]
Show full quote

Gmlb256 wrote on 2022-05-08, 23:12:

Shreddoc wrote on 2022-05-08, 21:58:

If it's not too much to ask - could we please have a comparison recording, with the same recording equipment and audio samples, but using a more mundane enthusiast ISA card (say an Audician32) ?

Without that, it's impossible (from a recording) to actually objectify how it differs from the norm.

For me all that obsession with getting the "cleanest" analog output are an audiophile thing. The most practical purpose I see for this is when using headphones.

Don't get me wrong, I would recommend that sound card considering the breath of compatibility with DOS games once it is released.

Seems like an excellent card, no doubt.

I'm just a fan of the "show, don't tell" school of marketing, which I why I requested a comparison recording from that poster. If he is kind enough to indulge, and has time.

A whole page of specs and endorsements is as nothing, compared with two simple recordings saying (for example!) "this is Common Game X; Recording1.ogg is a standard enthusiast ISA card (the Audician32), and Recording2.ogg is this new card. That massive difference you hear, is why we think this new card is awesome".

Sure I can record from an SB16 CT2770 tonight if that works for you? I have 50 ISA sound cards to indulge you but I would have to dig out an Audician if you require that specifically.

appiah4 wrote on 2022-05-09, 05:00:

Shreddoc wrote on 2022-05-09, 04:47:

Seems like an excellent card, no doubt. […]
Show full quote

Gmlb256 wrote on 2022-05-08, 23:12:

For me all that obsession with getting the "cleanest" analog output are an audiophile thing. The most practical purpose I see for this is when using headphones.

Don't get me wrong, I would recommend that sound card considering the breath of compatibility with DOS games once it is released.

Seems like an excellent card, no doubt.

I'm just a fan of the "show, don't tell" school of marketing, which I why I requested a comparison recording from that poster. If he is kind enough to indulge, and has time.

A whole page of specs and endorsements is as nothing, compared with two simple recordings saying (for example!) "this is Common Game X; Recording1.ogg is a standard enthusiast ISA card (the Audician32), and Recording2.ogg is this new card. That massive difference you hear, is why we think this new card is awesome".

Sure I can record from an SB16 CT2770 tonight if that works for you? I have 50 ISA sound cards to indulge you but I would have to dig out an Audician if you require that specifically.

Thanks a lot.

Re: which card to use for comparison. My personal preference would be an Audician32 (or other YMF71x clone ISA card), or alternatively, an ESS186x-based ISA card. I choose those because they are common ISA card choices among scene enthusiasts, due to their high compatibility, "competent quality" outputs, and generally less issues than Creative cards.

Joseph_Joestar wrote on 2022-05-09, 02:27:

darry wrote on 2022-05-08, 23:39:

Oh, and I have noticed that unlike every other CMI8330 or HT1869v+ based card that I have seen, this one actually has a 14.318MHz oscillator on board rather than sourcing that clock from the ISA bus. Is that a first for a card based on that chip ?

The one integrated on my PC Chips M571 motherboard has that oscillator too.

Maybe it was only the standalone CMI8330 cards that omitted it?

Since the the audio functionality is integrated on the motherboard on the M571, it would make sense to use the OSC that would need to be installed on the motherboard anyway in order to comply with ISA spec for audio purposes as well ( unless you meant that this motherboard has 2 such oscillators).

AFAIK, one reason for ISA cards often having their own oscillator was to avoid issue with out of spec motherboards . A properly designed and built motherboard with onboard audio would have no issues with there being a single 14.318MHz oscillator.

Issues possibly due to oscillator concerns :

MP3s slightly slower on old '90s pc with CMI8330

http://www.os2museum.com/wp/the-isa-osc-mystery/

darry wrote on 2022-05-09, 15:34:

AFAIK, one reason for ISA cards often having their own oscillator was to avoid issue with out of spec motherboards . A properly designed and built motherboard with onboard audio would have no issues with there being a single 14.318MHz oscillator.

It is also useful when overclocking the CPU on several motherboards (even if they are well built) as the ISA bus can get out of spec without the proper divider.

Gmlb256 wrote on 2022-05-09, 16:13:

darry wrote on 2022-05-09, 15:34:

AFAIK, one reason for ISA cards often having their own oscillator was to avoid issue with out of spec motherboards . A properly designed and built motherboard with onboard audio would have no issues with there being a single 14.318MHz oscillator.

It is also useful when overclocking the CPU on several motherboards (even if they are well built) as the ISA bus can get out of spec without the proper divider.

I could be wrong, but AFAICR, that 14.318MHz signal should always be at that value, regardless of ISA bus clock, which can vary.

Yeah, that signal is not supposed to change but there are motherboards where the signal is off or altogether missing (chaintech 6VIA5T for example).

appiah4 wrote on 2022-05-09, 04:58:

RichB93 wrote on 2022-05-09, 00:11:

WTF I love C-Media now. Seriously though, this looks really cool.

appiah4 wrote on 2022-05-08, 18:24:

I have been using this card in my daily driver retro PC (Cx5x86-120) for three days now, and this is by far, by a long long long far, the most amazing ISA sound card I ever used.

I mean, just listen to this recording. This is captured from the card's Analog Line Out using a Behringer UMC22 USB DAC. Brilliant..

Dune - Arrakeen Palace

How come one of the audio channels sounds inverted? Is this just how the Dune soundtrack is (sorry, I've not played it!).

(EDIT:I thought) I recorded with L/R inverted by mistake so manually swapped stereo channels in Audacity. AFAIK this swapped version is the correct way it should be, but if I was actually right the first time and swapped channels in error let me know and I will fix it tonight (LOL)

EDIT: Just checked and I was actually right the first time around, I will fix that tonight sorry.

I fixed this error. Updated recording: Arrakeen Palace

I also fixed the link in my previous post.

Shreddoc wrote on 2022-05-09, 05:24:

appiah4 wrote on 2022-05-09, 05:00:

Shreddoc wrote on 2022-05-09, 04:47:

Seems like an excellent card, no doubt.

I'm just a fan of the "show, don't tell" school of marketing, which I why I requested a comparison recording from that poster. If he is kind enough to indulge, and has time.

A whole page of specs and endorsements is as nothing, compared with two simple recordings saying (for example!) "this is Common Game X; Recording1.ogg is a standard enthusiast ISA card (the Audician32), and Recording2.ogg is this new card. That massive difference you hear, is why we think this new card is awesome".

Sure I can record from an SB16 CT2770 tonight if that works for you? I have 50 ISA sound cards to indulge you but I would have to dig out an Audician if you require that specifically.

Thanks a lot.

Re: which card to use for comparison. My personal preference would be an Audician32 (or other YMF71x clone ISA card), or alternatively, an ESS186x-based ISA card. I choose those because they are common ISA card choices among scene enthusiasts, due to their high compatibility, "competent quality" outputs, and generally less issues than Creative cards.

I will repeat the recording using this card on the weekend, but don't expect it any sooner as I will have to dig it out of a storage box 😀 Will this work for you?

I have a challenge for the astute listeners among us. I have attached two MP3 files. Listen carefully; decent headphones will probably help. Have a look in an application such as Audacity, and even mix the files down to a monaural track and listen again, if you want to cheat a bit. What do you think these files are showing, and what do you think of the results? Unless someone gets it right, I will offer hints or explain my trickery soon.

640K!enough wrote on 2022-05-10, 06:52:

I have a challenge for the astute listeners among us. I have attached two MP3 files. Listen carefully; decent headphones will probably help. Have a look in an application such as Audacity, and even mix the files down to a monaural track and listen again, if you want to cheat a bit. What do you think these files are showing, and what do you think of the results? Unless someone gets it right, I will offer hints or explain my trickery soon.

Just a guess based on a quick look at square.mp3 : mono track split (duplicated) to stereo, one side inverted. Results in a sort of "spatializer" effect, or "enhanced stereo" as some of the old boom boxes used to call it. With further uneducated (on my part) speculation that some frequency or phase 'issues' (or adjustments, if you prefer the term), as a result of the interacting channels, are a resulting 'compromise'. I've probably missed something but I don't have time for a fine microscope session.

Might I ask the purpose of the challenge?

Shreddoc wrote on 2022-05-10, 08:53:

Just a guess based on a quick look at square.mp3 : mono track split (duplicated) to stereo, one side inverted. Results in a sort of "spatializer" effect, or "enhanced stereo" as some of the old boom boxes used to call it. With further uneducated (on my part) speculation that some frequency or phase 'issues' (or adjustments, if you prefer the term), as a result of the interacting channels, are a resulting 'compromise'. I've probably missed something but I don't have time for a fine microscope session.

Might I ask the purpose of the challenge?

Then inverting back one of the tracks should produce a track identical to the other.
Or in other words doing a "mix and render" from audacity on two identical tracks with one of the two inverted should produce a total silence.
Which is not exactly the case. But inverting one track results in almost the other track which makes me think if this is because of the compression, or there is something more. WAVs would clarify this point.

I'm also wondering what we're supposed to spot here.

konc wrote on 2022-05-10, 10:22:

Then inverting back one the tracks should produce a track identical to the other. Or in other words doing a "mix and render" fro […]
Show full quote

Shreddoc wrote on 2022-05-10, 08:53:

Just a guess based on a quick look at square.mp3 : mono track split (duplicated) to stereo, one side inverted. Results in a sort of "spatializer" effect, or "enhanced stereo" as some of the old boom boxes used to call it. With further uneducated (on my part) speculation that some frequency or phase 'issues' (or adjustments, if you prefer the term), as a result of the interacting channels, are a resulting 'compromise'. I've probably missed something but I don't have time for a fine microscope session.

Might I ask the purpose of the challenge?

Then inverting back one the tracks should produce a track identical to the other.
Or in other words doing a "mix and render" from audacity on two identical tracks with one of the two inverted should produce a total silence.
Which is not exactly the case. But inverting one track results in almost the other track which makes me think if this is because of the compression, or there is something more. WAVs would clarify this point.

I'm also wondering what we're supposed to spot here.

Indeed. At a moderate zoom level, the visual waveform appears approximately inverse. But at a more microscopic zoom, differences become apparent. I'm not sure if we're picking at straws here due to compression, or missing the point entirely.

Probably the latter. There's more going on here.

Shreddoc wrote on 2022-05-10, 08:53:

Might I ask the purpose of the challenge?

I will say only that it is directly related to this thread. To be perfectly honest, I'd be very surprised if anyone guessed what the recordings are, and what they're meant to demonstrate, before the details are shared. I will admit that both of you started by looking exactly where you were meant to look, and have been discussing the points that I meant for you to pick out, so that's good.

When all is revealed, I have a feeling that you will be somewhat surprised, and that the recordings will suddenly be more interesting.

Some recordings of Sim City 2000 on MK8330:

Sim City 2000 - Title Theme 01

Sim City 2000 - Title Theme 02

I hope the stereo is not reversed this time 🤣

640K!enough wrote on 2022-05-10, 18:04:

Shreddoc wrote on 2022-05-10, 08:53:

Might I ask the purpose of the challenge?

I will say only that it is directly related to this thread. To be perfectly honest, I'd be very surprised if anyone guessed what the recordings are, and what they're meant to demonstrate, before the details are shared. I will admit that both of you started by looking exactly where you were meant to look, and have been discussing the points that I meant for you to pick out, so that's good.

When all is revealed, I have a feeling that you will be somewhat surprised, and that the recordings will suddenly be more interesting.

Looking forward to the explanation, when the time is ripe. I don't want to speculate much more, given that correctly guessing is, apparently, unlikely 🤣. The only facts I can really deduce is that we have a stereo track whose individual channels are approximately inverted, but with other slight differences. It could even be 2 slightly different chips, one on each channel, for all I know. Or alternatively, any one of a million possible sources and processing chains, done in any one of a million ways, to end up with a similar result. So I'll wait with interest for the reveal.

appiah4 wrote on 2022-05-09, 18:14:

Shreddoc wrote on 2022-05-09, 05:24:

appiah4 wrote on 2022-05-09, 05:00:

Sure I can record from an SB16 CT2770 tonight if that works for you? I have 50 ISA sound cards to indulge you but I would have to dig out an Audician if you require that specifically.

Thanks a lot.

Re: which card to use for comparison. My personal preference would be an Audician32 (or other YMF71x clone ISA card), or alternatively, an ESS186x-based ISA card. I choose those because they are common ISA card choices among scene enthusiasts, due to their high compatibility, "competent quality" outputs, and generally less issues than Creative cards.

I will repeat the recording using this card on the weekend, but don't expect it any sooner as I will have to dig it out of a storage box 😀 Will this work for you?

Perfect! thanks, appreciate it. There is no rush, just whenever suits your schedule.

I will share another detail, with the whole story to follow over the weekend. There has been much discussion about the CMI8330 implementing a "perfect" copy of Yamaha's FM technology, and this demonstration was started in the hopes of answering that question once and for all. In my recent recordings, the two channels are from different FM implementations, synchronised so that both play at (almost) exactly the same time. A few have had a look in Audacity (or similar), but the key is in listening. Separate the channels into two separate monaural tracks and export them, if you think that makes it easier. Try an A/B comparison. Do you notice any differences? What do you like/not like? If I hadn't told you they weren't from the same device, would you realistically be able to tell just by listening?