Xref: utzoo comp.dsp:155 sci.electronics:8016
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!gatech!gitpyr!byron
From: byron@pyr.gatech.EDU (Byron A Jeff)
Newsgroups: comp.dsp,sci.electronics
Subject: Re: Digital Mixer Using Burr-Brown 200 Khz ADC
Keywords: DSP, Mixer
Message-ID: <9240@pyr.gatech.EDU>
Date: 29 Sep 89 22:15:56 GMT
References: <9231@pyr.gatech.EDU> <1989Sep29.054029.1605@ccu.umanitoba.ca>
Reply-To: byron@pyr.UUCP (Byron A Jeff)
Organization: Georgia Institute of Technology
Lines: 54

In article <1989Sep29.054029.1605@ccu.umanitoba.ca> rahardj@ccu.UManitoba.CA (Budi Rahardjo) writes:
>> [This is my diagram]
>>-----------  ---------  ---------  --------   --------  --------  --------
>>|8        |--|Analog |--|Filters|--|      |   |      |  |      |  |      |
>>|Audio    |--|Multi- |  |  and  |  | ADC  |---| DSP  |--| DAC  |--|Filter|
>>|channels |--|plexors|--|  S/H  |--|      |   |      |  |      |  |      |
>>-----------  ---------  ---------  --------   --------  --------  --------
>
>Any comments?
>
>I've questions :
>What type of Analog Multiplexors ,Filters, S/H are you going to use ?

My understanding from a previous message is that the S/H is built in.
As for analog multipexors and filters I'm an ingnorant novice looking
for reccomendations. Any suggestions?

>Are they fast enough ?

I don't know.

>How do you control the mixer ? By modifying parameters of the DSP ?
>Can you control each channels ?
Through MIDI for me. I'm in the process of building the ultimate Midi-Merger,
sequencer, drum machine and adding mixer control is no problem. I'm am a
novice to DSP (that's why I read the newsgroup with great interest) but
with a M.S. in C.S. I think I can handle the programming and the math.
Modifying the DSP parameters through MIDI is the plan. How much control
over each channel I get depends on the processing power (I figure I'll get
this in a bit when I get to comp.dsp) but having individual channel control
would be desirable.

>Are you going to store /buffer the data in RAM before process them
>with the DSP or just pass them thru ?

Again it depends on the speed of the processor and the types of effects
I'm trying to get. I figure I may have to buffer a bit (up to 16K x 24 bits)
but I don't perceive that as a real big problem.

>Well your design is possible, but I don't think that's an easy job..
That's the kind of data points I'm trying to gather. If I can put it together
in a handful of weekend for $250-$300 (simplified by the fact I have
access to a DSP evaluation board) then I'll do it. Otherwise I'll leave
it to some genius to do. I'm looking at it just as a hobby project.

>Budi

Thanks for the comments. Keep 'em coming!
BAJ
-- 
Another random extraction from the mental bit stream of...
Byron A. Jeff
Georgia Tech, Atlanta GA 30332
Internet:	byron@pyr.gatech.edu  uucp:	...!gatech!pyr!byron