40106 6 voice osc. mixing issue

[petey twofinger]

i breadboarded a 40106 with 6 oscilators (cds cells) and the problem i am having is with mixing . i have tried diodes which i like the sound of , and also using a few resistors to ground boosts it a lil more , i tried all sorts of combos . the problem is when i add the 6th voice things cut out and battle for amplification . especially a lower pitchs . i would lke to hear all the voices , i tried 10k , 47k and 100 k resistors . taking 3 voices each with a diode to one point , with a resistor to ground then joining that to the output with the identical setup for the other 3 , also a 10 k at the output to ground seemed to help but ...

if i cant hammer out the all 6 channels sounding clear could i do 2 of the channels on the chip for lfo ? would i be able to use the 2 extra cds cells to control that ? then i am guess ing 2 of the oscilators would have lfo and 2 would not . this might sound cool .

any one that could help with an i dea or experience .

i have to look for schematics for doing simple lfo on this chip , any one ever try this ?

just so you understand each channel has a diode , 3 of those channels go to a point with a 10k going to grond , then to the output , the output has a 10k to ground as well . the other 3 oscilators each have a diode going to a point with a 10k to ground , then to the output  .

i tried resistance mixing , didnt care for it as much . but i dont think its using the diodes that is making it cut out . when i pull the cap out of one of the channels , any one , it cleans up nice and you can hear it great . i am guessing i am doing something wrong and there is a simple way to acomplish this , even if i need to add a 386 ... i looked and almost all the schemes only have 4 voices , i couldnt find anything in detail about 6 .... i am wondring if it can even be done and sound good , cause it sounds like crap with 6 , and i already did the chassis with 6 cds cells .

i want to try a starve too ...

thanks , petey .

[expanoncolin]

I think in general you can't expect to get very reliable mixing unless you use an active mixer, eg like this:



and even then you may not get great results unless you buffer each output, not sure how the 40106 behaves.  I am not sure at all why going from 5 to 6 mixed sources is creating an issue in your case.  In terms of doing a simple LFO, just raise the timing capacitor of the oscillator in question until the frequency is sufficiently low.  You can then feed the output to an LED and use it to modulate a CDS cell like you're suggesting.

-Colin

[petey twofinger]

i was afraid thats the answer i was going to get .

the issue is , like an idiot i built the enclosure first , and it features 6 cds cells .

i am going to work on the breadboard and see if i can get some sort of compromise . it would be great to go with 5 and have that 6th cds still do something . i am thinking lfo , but i dont have a clue , i need a schematic or something .

its the same problem i always run into , not enough room inside . this thing has a speaker and a seperate amp circuit .

thanks collin .