VOGONS


First post, by deeped

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hello there,

I decided to record and store some old DOS games' music 😀 (adlib/FM source). I need some ideas how to do it.

I know I will save WAV format with 44100, 16bit, mono format. How to minimize the noise? The source cmp is a desktop and Im recording on laptop. The laptop wont be plugged into connector to decrease the noise. How to decrease the noise as low as its possible? I dont care the size what samples will take I only care the quality.

Or theres another problem: some games music's volume is normal (blue demon's intro) and some of is not (doom1 / e2m4) I dont wanna tracking the volume button allways. Silently music causes more noise, how to eliminate that?

Reply 1 of 14, by 5u3

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Hmm, sound like a tough job...

If you're going for the best possible signal quality, I'd recommend recording the OPL2/3 output digitally. This is possible with the Soundblaster AWE line of cards, which feature an onboard SP/DIF output connector (it is only advertised with the SB AWE64 Gold, but most AWE models have it, you only need to build a very simple connector cable).

The good thing of this method is that the signal doesn't get converted to analog in any stage of the chain (OPL3 -> EMU8k -> SP/DIF -> recording device), and the usually noisy SB Mixer doesn't do any harm.
The bad news is that you need a digital recording device plus an AWE card, and you have to be rather picky about the AWE model, because many of them didn't sport a real OPL chip any more, but came with Creative's CQM FM emulation, which sounds a bit different.

For analogue recording, find a soundcard with a real OPL3 and quiet mixer. Creative's cards are a rather bad choice, because the ones with a real OPL chip are very noisy, and those with better sound quality usually come with the "fake" FM (as mentioned above).
Some cards from other manufacturers are reported to have a better output signal, however I can't say anything about these (Maybe other VOGONS members know more about suitable models).

If you really have to resort to analogue recordings from a Creative card, take a look at the Master Mixer utility, which I reviewed here.
(part of this epic thread over at QuestStudios, in case you're interested in some SB16/AWE details).

Reply 2 of 14, by Moogle!

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Disabling the onbaord amplifier on cards where there are only three jacks helps alot when doing analog. They're labled something like OPSL and OPSR, and they're right next to each other on the card.

Reply 4 of 14, by 5u3

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deeped wrote:

uhh im a bit confused about digital/analog now. What is the difference beetwen digital and analog right here? I thought I use digital.

The difference is how you get the audio signal from the FM chip to your recorded file.
The FM chip produces a digital signal, and the WAV file at the end of the chain stores it in a digital format. But on the way it gets converted to analogue and back, passing mixers and amplifiers, which adds most of the noise. You can reduce the picked up noise by selecting high quality components, but you can't eliminate it completely.

Reply 5 of 14, by 2Mourty

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I know that creative SB16's are notoriously noisy; I have used several of them and can attest to this. How about one of the first Vibra SB16's like the CT2800? It has a yamaha OPL chip and is much less noisy than other earlier SB16's.

Reply 6 of 14, by Malik

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Hi deeped. I wonder what soundcard you have in your desktop?

The simplest way is to connect the line out or speaker out from your desktop's soundcard to the line-in of your laptop, if you have the line-in in your laptop that is. You'll have to use a male to male stereo 3.5mm trs plugs. (The same size of your conventional headphone's plug.)

Or the other way round if possible.

But then, you need a software to record the source from line-in of your soundcard.

Creative's X-Fi mixer has an option to "Record What You Hear" option. So you can use a single pc with dosbox and record whatever you want directly to a file. You can also save it to mp3 or wav and the like.

There must be other softwares that can do this too.

Reply 7 of 14, by Zaarin

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If you're going for the best possible signal quality, I'd recommend recording the OPL2/3 output digitally. This is possible with the Soundblaster AWE line of cards, which feature an onboard SP/DIF output connector (it is only advertised with the SB AWE64 Gold, but most AWE models have it, you only need to build a very simple connector cable).

Interesting, have you tried this yourself? I own an SB32 and I tried making an SPDIF cable. However, the OPL chip is hooked up directly to two DACs which are then hooked up to the amplifier bits. The OPL output doesn't go near the EMU chip at all and so I could only record the EMU's output.

Reply 8 of 14, by Malik

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I have an AWE64 Gold, and am using both the digital S/PDIF and analog outputs from the card. Both the OPL sounds and EMU sounds are passed through S/PDIF.

The digital output goes to my AV receiver and the analog output is connected to my 2.1 speaker system. This way, the digitized sounds like speech and explosions goes to my 2.1 speaker setup whereas the music from either OPL or EMU processor is played through the AV receiver at the same time. Hence, you won't need to compromise too much the sound quality of the music played via the said processors.

For example:

1.) Heretic, Doom2, etc. - AWE32 wavetable sounds via digital and the digitized sounds via analog. [For EMU Processing]

2.) Dune II - OPL sounds via digital and digitized sounds via analog. [OPL processing]

Reply 9 of 14, by 5u3

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Zaarin wrote:

Interesting, have you tried this yourself?

Yes. Worked on all AWE cards I ever owned.

Zaarin wrote:

I own an SB32 and I tried making an SPDIF cable. However, the OPL chip is hooked up directly to two DACs which are then hooked up to the amplifier bits. The OPL output doesn't go near the EMU chip at all and so I could only record the EMU's output.

Through my magic crystal ball I see... Hold on... Yes, it's becoming clear... Your SB32 is a CT3930! 😳

Seems you've got the only card which can't pull off the digital recording trick (there might be others, but this is the only card I know).

There is a simple way to test this: Execute

AWEUTIL.COM /S /C:100 /R:100

and fire up any game with OPL support.
If you hear a cacophonic mess which sounds like someone is playing a cheap boombox at maximum volume in a parking garage, then your card should support OPL output via SP/DIF.
In case it sounds normal, then the OPL on your card isn't connected to the EMU8k, and you'll have to resort to analogue recording (or get a different card).

Reply 13 of 14, by 5u3

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Just a few corrections on the "Recording FM sound digitally from an AWE card" topic...

The last time I used the AWE SP/DIF output was several years ago. When I re-connected the digital output today in order to record some samples, I ran into some issues I had forgotten about:

  • On AWE64 cards the SP/DIF output is not automatically activated when running AWEUTIL.COM under DOS. This probably has to do with the newer SP/DIF output on these cards, which supports routing signals from the CODEC as well, not only EMU8K.
    If anyone knows a tool for activating the AWE64 SP/DIF under plain DOS, please let me know!
  • Some cheaper models only have the solder points for the SP/DIF output on the card, but lack the 2-pin connector to connect the cable. It is not difficult to mount a fitting connector if you have some soldering skills. Usually the solder points are somewhere near the EMU8k chip (marked "SPDIF"). I just added a connector to a CT3670 SB32, the digital output works fine!

BTW, if your digital recording device only has optical TOSLINK input (like mine), and you don't want to buy a converter, just build your own, consisting of some wire and a LED.
I found this youtube video, which shows how it works. 😁

Reply 14 of 14, by keropi

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AWESOME video 🤣
I never knew digital-out was like this... through a led!

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