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another problem with my splitter thing can someone help. . . . again? Answered

ok so i have this splittedr thing and everyone tells me i need a mixer circuit and i under stant that compleatly and when i perfect the master vol and selecter switches i will do that but for now i need help making the master vol and switches to work

the swtches problem is that if you turn off the switch (the 1/8" jack switch for example) sound still goes through the only hing the switch is doing is turning down my subwoofer to almost being unaudible  --no one needs that-- also turning what seems like voice and bass guitar off making a song instrumintal :/
and the volume ccontrol is acting like a ballance controller not volume. it is switchin my left speaker with my right so all sound goes to one set or another or the volume is halfed

so how can i fix this
other than the placement of the jack its looks exactly like the real thing

i know the first piture is confuseign so use the other pic as a referance


This looks a real mess. I particularly don't like that your controls are wired on the GND line.
A simple diagram for two inputs below, consider wiring things up like that. The input part can be copied for more inputs.



wher ewould i get double pole input volume controls and how would i use them?

LIke they said: Mixer. Op-amps are Really Cheap and VERY much worth learning to work with, and there are lots and lots (and lots!) of sample circuit designs you could base yours on.

(Standard plug here for The IC Op Amp Cookbook, by Jung -- Amazon has it -- which is definitely not written for beginners but is MARVELOUS for anyone who has some electronics background and wants to learn to work with these. Manymany sample circuit designs, with detailed discussion of exactly what design decisions are involved in them so you can adapt them to your needs -- and an introductory section which explains the "infinite gain amplifier" approach to designing with op amps, which describes their behavior surprisingly well when they're used properly.)

it just so happin i have an op amp lying aroundi an look into thatand your saying an op would work for this?


Even cheap ones like the 741 will get you going, the NE5534 is a highly regarded audio amp.

Build a unity gain buffer for each input (X2 for stereo) to begin with Volume controls on the inputs to the buffers.. Sum all those with an inverting amplifier.

Job done.

Buffering first *would* be cleaner. Though the typical large input resistances used with op-amps might provide enough isolation for normal use.

Again, there are many good examples on the web.

The simplest mixer you're likely to see is an op-amp configured as a unity amplifier with as many inputs as you need. Websearch "op-amp mixer" should find many examples, from trivial to fancy.

Simple, effective, cheap, beats reinventing the wheel.

The other solution, if you just want one input to one output at a time, is a two-pole, N-throw switch. I've got a simple three-way switch box that I use to route audio signals on my desktop, together with the input selector on the scavenged stereo amplifier.

Like we all said last time, without a mixer all bets are off. You are in grave danger of wrecking something !


i know. the design is not in use yet and has olny been used as a test run plugging only one input to one output in the test run


8 years ago

As I told you last time, you need a mixer.  I sent you links to various mixers that would work.  Please don't waste any more of your time trying to do it this way!

yes and i uder stand but util i can go to radioshak and be ridiculously over priced for my stuff i cant build one yet so im not useing the design until it works
if you can think of a good way to earn money i dont know wha else to do