VOGONS


First post, by kanecvr

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Hi guys. I recently picked up some retro stuff and among everything are these two ISA sound cards that stood out. Does any of the two have a built-in wave table? Is there anything special about them?

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Reply 1 of 11, by jesolo

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Don't know much about the Mozart based sound card but the Aztech model you have is based on their third generation chipset and has very good Sound Blaster Pro II compatibility (it is also Windows Sound System compatible).
Both cards have the original OPL3 chip on board.

Unfortunately, none of these have on board wavetable synthesis but, the Aztech card does have the Waveblaster connector (can't quite make out the connector on the Mozart based card and whether that is also the same connector) that enables you to connect a MIDI daughterboard. It also doesn't suffer from the infamous MIDI hanging note bug.

The Aztech card is not plug and play but, works fine under Windows 3.1x/95/98.
The drivers are available under Vogonsdrivers.

Reply 2 of 11, by Jepael

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The Mozart board is missing the joystick port cable, while the Aztech has no parts missing.

And the Mozart does not have a wavetable header, but it has some kind of daughterboard header for something, so that is a bit special.
At least Mozart-16 has jumpers to select between OPL3 and OPL4, so it could be a place for OPL4 daughterboard.

The Aztech has standard wavetable header, and some expansion connector with ISA signals which is a bit special.

But can anyone find any expansion boards for either card, I don't know.

The Mozart board has TL084 op-amps which just a bit noisier than the TL074 op-amps on the Aztech board.

They both have the same WSS chipset and same 6W amplifier. And they both have original Yamaha OPL3 chipset (which I value), the Aztech board has a separate 14.318MHz crystal for it so it does not use the 14.318MHz from ISA bus like the Mozart board.

So they are really very similar.
If I had to choose, I'd maybe prefer the Aztech board, because it is not missing the joystick port and it has standard wavetable header and less noisy op-amps.
Of course the wavetable header is not important if you have no wavetable daughterboards.

Reply 3 of 11, by orcish75

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Like Jesolo, I can't comment much on the Mozart board. From the little I have read on it, the Sound Blaster compatibility isn't great.

The Aztech card is fantastic, it's my second favourite card in my collection, after the Turtle Beach Tropez. The analogue circuitry on the output has been very well designed. It's a very quiet card (if you're using the line out), you'll only notice some hiss at really high volumes. It has it's own 14.318 MHz crystal as pointed out by Jepael as well as a 7805 voltage regulator which removes a lot of noise from the supply lines. The OPL is very clear and unfiltered (this might not appeal to some people who like a bit of "grunge" to the sound, like in the SB Pro II and some SB16's). The Crystal CS4231 codec has a high signal to noise ratio and playing 16-bit WAV's or MP3's on this card is a pleasure. SoftMPU works perfectly on this card as long as you have setup the address and IRQ of the MPU-401 correctly.

You can boot off the IDE port if you use the XTIDE rom. You don't need to pre-load any drivers in order to activate the IDE port unlike the Yamaha YMF-71x and OPTI 9xx cards. I'm using this card in my Amiga A2000 with a 286 PC bridgeboard and booting DOS from a CF card on it's IDE port.

SB-Pro compatibility is spot on. I haven't come across anything yet that it doesn't work with.

Some negatives of this card:

IRQ hog! This card requires 4 IRQ's if you use all the features, one for the SB Pro, one for the MPU-401, one for the WSS and one for the IDE port. The Yamaha YMF-71x cards only use one IRQ for the SB-Pro, MPU-401 and WSS.

The mixer for the OPL when in DOS mode doesn't work as expected. If you adjust the volume from 10 down to 1, it seems as though you've only adjusted it down to 7 and then nothing when you go to 0. The OPL volume is much louder at low levels than the WAV at low levels. Once you've found a balance between the OPL and WAV, it's fine, it's just annoying when you first set it up.

When in SB-Pro mode, the 8-bit samples seem to sound a little scratchy. It's not bad, some people may not even notice it, it's just one of those things that when you hear it for the first time, you'll never be able to ignore it. The Yamaha YMF-71x cards seem to exhibit the same scratchyness in SB-Pro mode.

Overall, it's a really good card. The low noise, clear sound and good SB-Pro compatibility are the biggest plusses. If you setup the card correctly, I doubt you'll be disappointed.

Reply 4 of 11, by boxpressed

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I talked about a card that's similar to your Aztech in this post:

Bought these (retro) hardware today

Any full-height ISA card with an OPL3 and a DB header in the appropriate place is worth keeping. Genuine OPL3 SB Pro compatibility and no hanging note bug = win.

Reply 5 of 11, by kanecvr

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I'll give both cards a go tomorow. I'm really curious to see how the Aztec sounds compared to my old YMF card and my CT1600.

One last thing - I noticed the Aztec card has a room for a PC speaker input header but it's not populated. Near it there are pads for a couple of SMD resistors (r40 and r32). Any ideas as to what value this resistor should have? I rather like routing the PC speaker trough the sound card for games like Prehistork and Supaplex.

Reply 7 of 11, by kanecvr

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That's actually a good idea. Would have been cool to have a wavetable to test them with but I don't. I do recall there was a brand new wavetable you could buy - I think I've seen it demoed on phil'scomputerlab youtube channel - but for the life of me I can't remember what it's called.

Reply 10 of 11, by gdjacobs

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It won't be a PAS of any sort when using the Jazz 16 chipset. Jazz 16 does SB/WSS emulation.

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