basic audio mixer (4 channels to 1)?

[janklug]

hi,

i'm new to this forum (and basically to audio electronics, too, so please forgive any newbie mistakes ;-) )

i'm planning to build a very basic audio mixer, that should combine 4 channels (2 dynamic mics, 2 line level instruments) to 1 line level channel.

the level of the in's should be set individually, and i'd like to have a master fader, too.

i've searched the internet & found several designs that (more or less) seem to fulfil these wishes; unfortunately, i don't know the used amplification methods & their pros/cons, so i can't decide what solution would sound & work best...

does anybody have any idea wich of the following schematics to prefer, and/or answers to the related questions on that design?
any help greatly appreciated!

http://www.redcircuits.com//Page53.htm (looks like the best choice to me)
(question 1: do i need the full 'input module' also for the line level inputs?
question 2: what can be omitted to make it just a mono out?)

http://www-fa.upc.es/websfa/lab/111/audio/audmixer.txt
(question on this: Audio Taper pots - are that just logarithmic pots?)

http://home.maine.rr.com/randylinscott/may20.htm
(- question 1: does it need 9V power, or is that +9V / -9V symmetrical power? just heard of the existance of symmetrical power today ;-)
-question 2: what kind of caps are those? the 100uf seem to be polarized, but what about the 10uf at the outputs?!)

http://www.zen22142.zen.co.uk/Circuits/Audio/6ipmix.htm
(question 1: what are those opAmps? which model to choose for that?
question 2: this actually USES a symmetrical 9V power source, right?)

well, i found more, but these seemed to be fitting best.

thanks & greetings,

jan

 

[rfbrw]

You would be better served posing this question in the analogue forum.

 

[janklug]

You would be better served posing this question in the analogue forum.

ah, thanks for the tip!

greetings,

jan