Thinking Of Balancing My Guitar...Is It Worth It ?

[Incubus]

That's exactly what I'm getting at...........

I'll name my first born after you......though the savage beatings in school will be another issue.

This idea is in no way mine, but it seems that to people who play guitar, it's something new.

When I was working at an audio company about 20 years ago, one of the engineers said to me "Why don't guitar companies make a balanced guitar ?"

At the time, I didn't think much of it.....because I didn't understand what he was talking about, but since then, I've learned alot as we all have.

He was involved in community theatre groups at the time, and he was saying that the only noise problems they ever got were with guitars picking up buzzing from stage lights.

The logical step to him was a balanced guitar.

FWIW, I can assure you this guy was a *genius* when it came to audio.....one of those guys who could be told "We need one of THESE", sit in silence for 5 minutes, then draw a schematic that would work the first time.......I've seen him do it on numerous occasions.

The thread you pointed to is exactly right.....guitar should go in this direction, but whether or not they do is another issue.

Still....I'll keep digging and trying a few things, but I guess it will eventually happen.

[Hailstorm350]

I'll name my first born after you......though the savage beatings in school will be another issue.

lol that's hilarious.
anyays,

It's a great idea, and I've even been thinking experimenting on my squire 'frankenstein' guitar and installing an xlr jack and making the output balanced, and maybe even figuring out how to use the 48VDC as an alternative to battery-klunkiness.  then I could use the phantom-power to power internal distortions and..then maybe not, but 20 switches and levers on my guitar's already pimply face does sound tempting, because that's definitely what I'd do with it!

Oh well, just an idea.
-Ken

[toneman]

if the "noise" is 60HZ "humm", maybe a *very* selective notch filter might B usefull(?)
That comment in the BassDiscussion Forum was very good.
If U don't have a "gnd", U can never have a "gnd loop".
Have U tried a different cord, or a different amp??
What about polarity switching on the amp??
if U've tried all these things and still have the same "noise", MayB the differential(balanced)
approach might help.  Remember, the "advantage" to differential(balanced) input, is that
the "bad" signal is "balanced" out leaving only the signal U want.
Craig Anderton had/has several circuits that go from bal2unbal and also the reverse.
All use opamps and require a bipolar powersupply.  
Balanced outputs can drive longer lines withou picking up "noise" on the way to the amp
because of their *low* output impeadance.
If the "noise"  is a Shhhhhhhhhh, then it's not powerline(60hz)...
This is a totally diffenent subject...
Hey Moose, did U get that schematic.??
PM me soz i can get a copy...i'll send U the CA stuff.
staybalanced(or not)

tone

[seanm]

The balanced line will only help remove hum and noise picked up by the cable. If you have a single coil strat and it is picking up noise, you will faithfully send this down the cable and have it reproduced on the other end.

The balanced line will only help for very long cable lengths. For most of us, it will not help. The most I run is 20' from bass to effect(s), and then 20' from effect(s) to amp. Not enough to bother with.

[Pushtone]

To me this looks like a few of things.

1. An encode / decode scheme.
The signal is encoded (balanced), transmitted (cable) and decoded (unbalanced).

2. An active/passive DI set with built in phantom power.
The pickup outputs are electronically balanced to gain the benefit of a active buffer (encode), then unbalanced by a transformer to gain the benefit of transformer isolation (decode). The active buffer takes care of capacitance, the transformer takes care of ground loops. The balancing and shielded twisted pair cable take care of inducted noise. A two part system.

3. Similar in some ways to a couple of new products from the studio world.
http://www.littlelabs.com/std.html
http://namm.harmony-central.com/WNAMM05/Content/Radial/PR/SGI.html

Bottom Line: Will it sound better?
This is just what you need if you want VERY VERY long cables. Like 300 to 500 feet. And to sound as good as a 10 foot cable. But it won't sound better than ten foot cable.

I would not build this to go 10 to 20 feet to a guitar amp because of the cost of the Jensen transformer. I would build this to go 300 feet to a guitar amp. Maybe the circuit could be modified into a re-amper.?.

Beware: Cheap transformer sound bad. I'm talking phase distortion, and transformer saturation.  If you have ever gotten used to quality passive DI, then had to use the $29 Yorkville DI you will know what I mean.

If you use a Jensen transformer it WILL sound better because they are the best sounding audio transformers on the planet IMHO. Lundahl transformers are great too. But Jensen transformers start at $60 to $80 depending on the one you need. The Jensen scheme looks like their basic 1:1 transformer which is their lowest costing transformer.

I don't see why you couldn't do the reverse. Put a transformer in the guitar to get the signal balanced and then feed an active buffer pedal that outputs an unbalanced output. Wouldn't that save you the trouble of building a 48V phantom power supply? It would be like having a passive DI in your guitar.

Note: The Jensen scheme shows a 1/4" TRS phono jack. Why would you want to use a big honkin XLR on a guitar?

OT: Kinda reminds me of that part in Hitch hikers Guide to the Galaxy where the rock band is playing in a space ship that is traveling at light speed away from the asteroid where their amps are because it is so LOUD . Rn'R baby. :wink:

[moosapotamus]

Regarding the onboard diff-amp approach, a couple things worth highlighting... I think toneman picked up on the first one...

...If U don't have a "gnd", U can never have a "gnd loop"....

The other point worth mentioning is that, with this approach, there is no balanced line coming out of your guitar. The onboard amp has a differential input and a single, unbalanced output. You don't need an XLR output jack. You still use a regular guitar cord.

The guy on talkbass was nice enough to send me his schemes (thank you, nonsqtr!). He was pretty open and willing to share his work freely. But, since it is not my work, I may take these down as soon as I have a chance to redraw them. There are a few minor errors and clarifications that should be made (such as some incorrect opamp pin numbers) anyway...
http://www.moosapotamus.com/DIAP/diap.jpg
http://www.moosapotamus.com/DIAP/preamp.jpg

I think the reason for the above is to eliminate noise, not to try to drive a long cable or do something magical to your "tone." For dealing with things like long cables and direct inputs, I agree, just build an outboard box. Phantom power is workable for a DI or buffer box, but it's typically very low current. That might be a concern for folks who still want to do all of this onboard, depending on how much "stuff' you want to build into your guitar.

~ Charlie

[putrefusion]

...no.

[markusw]

In short, instead of grounding one end of your pickup(s), one end feeds the non-inverting input of an opamp, the other end feeds the inverting input.

This is basically how the Carvin A500b preamp is wired. With my Barts 59J pickups however I do not experience a higher noise level with my NTMB than with the Carvin, but maybe that's because the 59Js are split coil design.

Markus

[lovekraft0]

The balanced line will only help remove hum and noise picked up by the cable.

Everybody seems to be missing seanm's point - unless your noise problems are generated in the cable, a balanced output won't change anything, since the noise will already be in both phases of the signal, and won't be cancelled. Adding a transformer to a guitar that already has noise/hum problems is likely to make matters worse. If the only issue is matching the output to a balanced XLR, an adapter at the board is a much easier solution - if you want a low impedance output to compensate for cable capacitance, a voltage follower is much cheaper (and potentially hum-free). A transformer is also, for better or for worse, going to change the sound of the pickups - see Jack Orman's Lab article on pickup simulation for the specifics.