Mixer for MCA SoundBlaster Clone/replica \ VOGONS

Mixer for MCA SoundBlaster Clone/replica

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First post, by Jinxter

Posted on 2023-10-21, 18:21

Jinxter Offline

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I have this Sound Blaster MCA replica from David Larsson. https://www.tindie.com/products/kdehl/mca-mic … laster-replica/
I am having trouble using a mixer software to set the volume for e.x. FM, Master, Line In, Mic, in etc.

I have tried both drivers for Sound Blaster MVC. The one for CT5320 driver has no program to set volumes.
The CT5330 driver has a sbp-mixer.exe and sbp-set.exe - none of them are doing anything with the volumes.
I also tried UNISOUND and something i found on the Internett called SBPVOL Ver. 4.01 25-4-98 (C) SGM Soft

Maybe the CT5320 and clones like David's SB MCA don't have mixer capabilities?

On Wikipedia we can read: "The Sound Blaster Pro supported faster digital input and output sampling rates (up to 22.05 kHz stereo or 44.1 kHz mono), added a "mixer" to provide a crude master volume control (independent of the volume of sound sources feeding the mixer), and a crude high pass or low pass filter."

I guess maybe that explaines my problem?

Anybody have any thoughts on this?

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Reply 1 of 1, by mattw

Posted on 2023-10-21, 18:54

mattw Offline

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I see the card has "a knob" on the back - I guess for adjusting the volume, that's your "mixer". So, other than that at first glance, as far as I can tell, there is no chip on the board that can serve you to adjust the volume, the Xilinx chip is implementing the MCA bus as per the code here:

https://github.com/schlae/snark-barker-mca

and the rest of the chips are just off-the-shelf ones, you can get their datasheets to see what they are doing. However, I am not an expert - it's possible the problem to be related to the DSP code inside the ROM chip - there are 2 ROMs - mentioned on the above aforementioned Github link.

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