DIrect solutions...

[jishnudg]

So here's what I've been planning...
To insulate my live setup against unpredictable venue amps, grounding issues etc I've thought of the following solution. I play in a quartet with a bass player, drummer and pianist.

Guitar In ---->  Overdrive  ----> Buffer/Splitter ---> 3 nos. "Send" ----> Active 4 channel Mixer ----> Cabinet Simulation (switchable) ----> isolation D.I

The principle being that after amplifying the signal with the overdrive and buffering it, I can split it into 4 parts...3 will be used for 'Send' purposes, and the fourth will go into the channel mixer as the first channel. The mixer will accept the 3 'returns'  as well , amplify and level everything out with volume controls for each channel, and provide a single output into a simple switchable cabinet simulation (looking at Joe Davissons simple cab sim for this)....which would then be converted into a balanced XLR output.
So I'm looking at running all of these from a single 9v source...would that be possible? Can the mixer be made a passive one to reduce board space and size of the circuit? I would also like to use the mixer 'in's to connect,say an ipod output, so I can play along to jam tracks etc, and also have a headphone out and an unbalanced out at the tail end of the circuit, parallel to the balanced out. In general, how can the circuit be simplified so it doesn't merely become a set of effects chained one after the other?Particularly, what is the best way to DI the signal? I understand that the cab sim would provide some preamplification, so can a cheap passive transformer similar to this http://beavishifi.com/projects/Passive_IPOD_Preamplifier/Passive-iPod-Preamplifier-Schematic.jpg be used?

Apologies for the slew of amateur questions
Thanks,
J.

[Labaris]

Sounds like a nice project.
Maybe you should establish priorities for what you want the pedal (is it a pedal?) to do 

[GGBB]

So I'm looking at running all of these from a single 9v source...would that be possible?

Yes.

Can the mixer be made a passive one to reduce board space and size of the circuit?

Considering all the connectors that will be required and therefore the size of the enclosure that will be necessary, I don't think conserving board space will be a concern.  Even then, the transformer-based passive mixer, if it did what you needed, isn't likely to have a smaller footprint than something like this.

Check out the GGG Parallelyzer http://www.generalguitargadgets.com/projects/15-boostersrouters/67-the-parallelyzer-projec - it's not far off what you are describing.

[jishnudg]

https://docs.google.com/file/d/0BwMVia471c4Sdm1EcEtscUZDSGM/edit?usp=sharing

Here's something I worked out to be a very simple, no frills active D.I (to be put at the end of the circuit). I guess I wouldn't need a transformer then...Will this work?

[Labaris]

https://docs.google.com/file/d/0BwMVia471c4Sdm1EcEtscUZDSGM/edit?usp=sharing

Here's something I worked out to be a very simple, no frills active D.I (to be put at the end of the circuit). I guess I wouldn't need a transformer then...Will this work?

What is that last 470R resistor for? (between XLR2 and XLR3)
Wouldn't you nedd some gain and EQ for the headphones out?

[jishnudg]

Oh.sorry about that...yeah don't think there would be a 470R between XLR 2 and 3....well for the headphone out I intend to just tack on a 100R resistor to attenuate the signal a bit, and then split it and take it to a 1/8" headphone jack.