Mono guitar to stereo effects to 2 amps !?!

[Dimi Pana]

OK, I know the subject of my topic is unusual, to say the least. I will also admit that I am a noob and I know little about electronics, well just a few basics. I also looked up as best as I could into previous topics and could not find something similar.

So ... my apologies if what I will say makes no sense or is not doable. Also, sorry if this has been covered elsewhere.

Here it goes:

I am currently building my first DIY amp using this design --> http://beavisaudio.com/projects/NoisyCricket .

I used a Radio Shack board (see attached PDF) to build it thus I build two side by side.

These little amps are so easy to build, cost is very low, and each puts out no more than 1W of power. I tried both through an 8" speaker, and I also intend to build a 2x8" cabinet later.

--

I also have an old DOD multi effects unit (3 dimension) which has separate L and R input and output jacks.

I did some measurements and the dual-amp PCB can fit inside the DOD chassis, with all necessary in/out jacks and pots drilled on the DOD faceplate and backplate (after some creative artwork of course).

So ...  here's what I'd like to do IF possible:

Take my guitar's signal, split it in two, send one "half" to L and the other "half" to R input of the DOD, then take each output from the DOD (L and R) and send one to one amp and the other to the other amp. Finally, each amp drives each own speaker within the same cabinet. The DOD chassis will be mounted on top of the cabinet (slide-in, removable) and this whole contraption should measure about (18x22x8)" (HxWxL). Hopefully, it will sound OK. Not necessarily great but OK. I am not a professional musician, just for practice, jamming with friends and playing at (not-so-loud) parties.

-

So, are you still with me or looking for something to ...throw at me? (lol) (sorry, my jokes, as well my gadget ideas are lousy).

--

If you are still here, now it's time for some questions:

1. What is the best way to split the guitar signal in two equal/identical parts? Y-cord? Audio Mixer? small DIY circuit?

2. The DOD does not have separate volume controls for its L and R outputs. Therefore it makes sense to keep the amp controls separated too, having a L and a R side on my amp not only will look cool, but it can be practically useful to control how much/what effect goes to each side.

3. Since this simple amp design does not have FX in/out, what signal path is best?

a) Guitar to DOD to amp to speakers? (But how would this sound? Is n't it a wrong idea to insert your FX before the preamp?)

or

b) Guitar to amp to DOD to speakers? (would that work? I mean can the DOD drive the speakers? I do not think so).

c) If both a) and b) are not ideal, can anyone suggest if and how I can mod this little amp in order to use the FX unit?

--

So take your time, let me know if all this is possible or not. I understand it might not be worth the time or the money, and yes I agree, I do not intend to spend a lot of (more) money on it, but time, that I got, (no I'm not in jail) especially if this is going to be a fun project.

Thank you all so very much,

Cheers!

[joecool85]

Quick answer:

You can split it with a Y cable, but it is better to do it with an electronic splitter circuit using a TL074 or similar.

[Dimi Pana]

Quick answer:

You can split it with a Y cable, but it is better to do it with an electronic splitter circuit using a TL074 or similar.

Thank you Joe, I searched google using keywords "TL074 guitar signal splitter" and found some interesting results, I will "weed" through them and re-post with more info/questions if needed.

Thank you very much for all your help so far! 

[Dimi Pana]

Hello again!

The attached PDF is something I -with my limited knowledge- find as a viable better alternative to just a Y-cord (which should work but is NOT the ideal solution) especially since even I can build it with minimal effort and actually I could even attempt to integrate inside the entire chassis.

I did find some other more sophisticated designs based around the TL074 or similar but I would like to try something within my technical reach first.

Please let me know what you think.

Thank you!

[J M Fahey]

Yes, that Fet splitter (a buffer really) works, and can drive a dozen amps if you wish.
If I had to include one in a preamp I would use the suggested Op Amp version , but for building just one stand alone unit, probably in perfboard, this one is physically easier to build.
You may build it in a plastic box (easier to work with home tools) but cover its inside with grounded aluminum paper .
Add a 100 ohm to 1 K resistor in series with each output jack, to somewhat isolate each one from the others.

[Dimi Pana]

EDIT: 1st Schematic removed as not correct and all relevant discussion, from this post.

--

I am posting three designs I found in case anyone would care to comment on their pros and cons. I would n't mind the passive design and the loss of treble, I'm not a pro musician, so I do not really care. Nevertheles, these 3 are definitely beyond my building capabilities.  

Thank you!

[J M Fahey]

WOW !! , those are real Pro splitters, but maybe too much as a first project.
What I meant is building the original simple one, with just one FET, no more, its single output connected to 3 or 4 output jacks as needed, but adding a 100 ohm to 1K resistor in series with each jack´s signal pin.
All grounds are joined together, of course.
The output transformer isolated ones are meant to avoid ground loops in complex setups (as in Van Halen´s, Joe Satriani´s and similar Pro guys), but for home use the simple one is more than enough.
We are in DIY SSGuitar here, want to keep things within our average Member´s reach.

[Dimi Pana]

We are in DIY SSGuitar here, want to keep things within our average Member´s reach.

YES!

--

Funny, probably while you were typing your last message, I found this:

http://recording.org/diy-pro-audio-forum/43122-tips-making-guitar-output-splitter-please-2.html  <-- (look at the last post of that thread)

--

I was about to ask you if that's what you meant BUT you beat me to it!

I learned a lot today, I am getting off of my computer NOW, or I 'll be abusing your kindness.

Muchas Gracias!