Best way to build a guitar splitter?

Hi,
I would like to build a guitar splitter- 1 in and 6 outputs.
Can anyone recommend the best way to do this?
Thanks,
Freddy :sam:

I just built the guitar buffer from www.generalguitargadgets.com (under effects projects->boosters/routers) It works great. I built the discrete version (just an drain-follower fet with some biassing)

You could use this schematic or the ic version, which is an opamp used as a unity gain buffer, for one input buffer and six outputbuffers.

Many years ago I built one using a NE5534 as buffer and 2 V74 Input transformers wired backwards as output transformers. They have 2 windings, which I used as separate outputs, so there are 4 ground-free outs.
It works very well - apart from occasional radio interference between the outputs which are coming from the same transformer. People still love it, a friend borrowed the unit some months ago and he doesn't seem to want to give it back.
I want to build one with different opamp and output transformers, maybe the OEPs used in the 1176 projekt work?

Michael

You could always try the Jensen schematic, but that'll get expensive for all the transformers. What are you doing that needs 6 outputs?

OK so here is something I have just been working on Spiltting Guitars....

I too built the www.generalguitargadgets.com AB/Y pedal to split my guitar into 2 different heads. DON"T BOTHER!!! It has the worst sounding GROUND LOOP I have ever heard in my life. I bought the PCBs from them and used their parts list. Totally useless!!!

Here's what I have to do now....

Guitar to AB/Y (any type will do) then each channel to EBTECH HUM eliminator (60Hz ground loops), Then each channel into a noise gate (Your other efxs and line noise)

If anyone has a proven better solution then I am listening... But I have tried just about everything with other designs of Transformers and Buffers.

-ChuckD

couldn't you just make a mult like on a patchbay?

http://www.geofex.com/FX_images/humfree2.gif

http://www.geofex.com/FX_images/oaspltr.gif

Those xfmrs are only a couple bucks but they spec a 300-3.4K. Maybe cool for el. gtr, but for a few dollars more the Edcor would be a sonic improvement, and make the unit more versatle.

how about a JLM simple DI



followed by a TWO transformers JLM of course




and this way you will be buffered and the Strat will have >1meg load
and then
AC coupled to each guitar amp to avoid ground loops and hum

add a third trafo and you can DI to FOH


:shock:

sorry
shameless
shameless
plug, plug, plug
:razz:

http://www.geofex.com/FX_images/humfree2.gif

http://www.geofex.com/FX_images/oaspltr.gif

Those xfmrs are only a couple bucks but they spec a 300-3.4K. Maybe cool for el. gtr, but for a few dollars more the Edcor would be a sonic improvement, and make the unit more versatle.

Click to expand...

The point of the transformer isolators at GEO was to get acceptable results with cheap transformers.

Yes, those transformers are specified at 300Hz to 3.4K, but by driving the primary from an opamp output the measured low frequency rolloff point in that circuit is 60Hz, well under a guitar's 82 Hz low E.

The opamp output can supply enough current to go ahead and supply the current that would otherwise be eaten by the primary inductance being low, keeping the signal voltage up to appear at the secondary.

The measured high frequency response is up by 2db at 22kHz, and drops to -6db out at 28kHz.

Specs are what the manufacturer is willing to bet the purchase price that his parts can make. In this case, the maker is doing very well at the high end.

Better specified transformers are always a good choice if you can afford them, but for $2, the Hy-Q stuff is a pretty darned good response per dollar. By all means, use better ones if you like. The same low end trick works for all transformers if you need it.

But 60Hz to 28kHz seems to be enough for most guitars. :grin: :grin:

You could always try the Jensen schematic, but that'll get expensive for all the
transformers. What are you doing that needs 6 outputs?

Click to expand...

Well, I want to be able to play guitar, and have the signal simultaneously go to different guitar amps each mic'd and recorded to separate tracks so that I can blend them later at mixdown.
I've seen the jensen schematic....I'm not worried about the cost, just the best way to do it with as few "artifacts" as possible.
:? :sam:

[quote author="R.G."]

But 60Hz to 28kHz seems to be enough for most guitars.

Click to expand...

Unless you're doing the solo in Nowhere Man.

Thanks for that info.

> Those xfmrs are only a couple bucks but they spec a 300-3.4K

Without looking, just by those numbers, I bet these are "modem transformers".

Yes, 300-3,400, BUT often flat to 1dB or even -0.5dB across that band, when matched in 300-600Ω. Modem use wants a very flat response, but only a narrow band matters.

If it is -0.5dB at 300Hz, it is -1dB at 150, -3dB at 75Hz. The low guitar note is 82Hz, and guitar systems are never flat to 3dB. Already it is good enough. But as R.G. says, driving from a low-impedancee source instead of a matched-impedance source makes it even better.

These are still not "great" bass transformers. Low-loss is more important than anything below 300Hz, to a modem. The flip side of that tradeoff is not a lot to go wrong on the high end: not much leakage inductance, and not a heap of capacitance even with low-cost winding techniques. I actually think a top-ring at 22KHz is "awful" for a winding like this, but 2 octaves better than guitar needs and the little 2dB bump could be loaded-away for lo-price hi-fi chores.