I saw a pdf of a phantom powered buffer which gives a balanced output. Not sure of the link, but it's to do with Jensen......transformers I think.
The name of the file itself is "as004.pdf", should anyone want to search.
It consistes of a preamp which would go in the guitar, and some DI arrangement who's output would go into the front of the amp.
Anyway, if I balance my guitar, I would expect to notice the guitar being quieter.
My question is would I notice any other differences in the actual tonal quality of the sound ?
I ask this because years back, a singer in my band had a wireless mic, and we all noticed that the sound was ok, but wasn't "there". He got some advice about it and ended up buying a DI box. From then on, the sound was better, but it wasn't the type of thing that someone who hasn't been a muso for very long wouldn't notice......it was a more "positive" sound.
Just basically wondering about any advantages or disadvantages that trying this with my guitar would yield.
You could put a buffer (as on GG, very nice one!) in your guitar and phantom power it from the first box; I did something similar with my bass and it sounds really good. I don't know if a box at the begin of your pedalboard with a buffer (as I did with my guitar setup) would sound different than one in the guitar but I know that it makes my sound way better. No more loss of high end!
What I'm talking about is converting the unbalanced output of the guitar, to a balanced output which would require a different type of guitar lead.
It wouldn't be just a sheild and signal type cable, it would have the sheild and two conductors like a microphone cable.
Rather than using a normal mono plug to plug into the guitars socket, it would have either an XLR connector, or a 6.5mm stereo connector which would be wired as tip-ring-sleeve.
I use a stereo jack and plug to get the power from my box to my guitar. It works.
And yes, it is worth it. Even more when you have a lot of TB pedals.
QuoteRather than using a normal mono plug to plug into the guitars socket, it would have either an XLR connector, or a 6.5mm stereo connector which would be wired as tip-ring-sleeve.
I was too thinking about whether there is any benefit in having a balanced guitar (or im my case bass) output. XLR connector would be fine because it also would allow phantom power (no more batteries :D), in my case it's just impossible to install since I don't want to drill a hole that large in my bass :( . With a stereo socket (wich is installed for battery power switching in may bass anyway) no phantom power line would be free. So I had to do it w/o phantom power.
Would be really interested too whether it's worth a try. :?:
Markus
Maybe some of the people aren't exactly sure what I'm talking about.
Mark has the idea though.
My intention isn't "phantom powering"....it's balancing the guitar's output.
Here's the link to the pdf file at Jensen Transformers.
Maybe this will demonstrate what I'm intending:
http://www.jensen-transformers.com/as/as004.pdf
Quote from: IncubusMaybe some of the people aren't exactly sure what I'm talking about.
Mark has the idea though.
My intention isn't "phantom powering"....it's balancing the guitar's output.
Here's the link to the pdf file at Jensen Transformers.
Maybe this will demonstrate what I'm intending:
http://www.jensen-transformers.com/as/as004.pdf
You'll gain the usual benefits when dealing with buffers inside guitars. Increased high frequency response due to unloading of pickups, ability to drive long cables, etc.
However unless you know the equipment you're dealing with has balanced inputs, or you have massive noise problems with long cable runs, I really wouldn't bother building one inside the guitar. Say you want to plug into a regular guitar amp, you're still going to have to make some sort of balance to unbalanced driver. Better to make an active, unbalanced to balanced cable, which you can plug into your guitar, then use that to run balanced cable to whereever.
Did'nt know that it's possible to have balanced out plus phantom power with a stereo plug (via three lines including gnd). Always thought it needs two opamps for a balanced out. Looks like a clever circuit. If I got it right, V+ is basically run over the two signal lines. Great, so we just need to know whether it makes sense or if it's simply overkill compared to a normal buffered output. :?:
Markus
EDIT: too late!
if you want to change a hi-z guitar signal to a low z signal try one of these. you will still use a mono cable but a stereo jack for disconnecting the battery. battery goes in the guitar.
http://www.caesound.com/cgi-bin/cae/info?bufPreamp
i don't know if that necessarily will make it balanced. but may help. my 2cents. peace, waldo
QuoteHowever unless you know the equipment you're dealing with has balanced inputs, or you have massive noise problems with long cable runs, I really wouldn't bother building one inside the guitar. Say you want to plug into a regular guitar amp, you're still going to have to make some sort of balance to unbalanced driver.
Quote
In the diagram at the link, the left hand side of the schematic goes in the guitar.
The right hand side of the schematic is the conversion from balanced to unbalanced.....the output of which goes into a normal guitar amp.
Quote from: waldo041if you want to change a hi-z guitar signal to a low z signal try one of these. you will still use a mono cable but a stereo jack for disconnecting the battery. battery goes in the guitar.
http://www.caesound.com/cgi-bin/cae/info?bufPreamp
i don't know if that necessarily will make it balanced. but may help. my 2cents. peace, waldo
AFAIK that's just a simple opamp buffer. None of Garcia's guitars had a balanced output.
If you want to know the difference between balanced and unbalanced, there's a good explanation here:
http://www.mediacollege.com/audio/balanced/cable-balanced.html
It totally depends on your application, if you already have terrible noise problems where you play, using a balanced system from your guitar can help to a degree. BUT as usual, if you have noise problems, I would remove all the usual suspects first - start with the SOURCE and make sure your guitar is properly shielded (with no ground loops inside the guitar - see www.guitarnuts.com), use high quality cable, etc. before going crazy. Like you don't need a shotgun to kill a fly when a rolled up newspaper will do.
Oh yeah, if you use regular single coil pickups, you will ALWAYS have some noise and hum, when not in hum cancelling positions (2+4 on a Strat).
The thing is, I'm not having terrible noise problems....I get a little noise, but it's not excessive.
I'm just kinda curious as to whether or not there would be any other benefit to balancing the output.
For example, Alembic have balanced basses.....I guess with basses it is more common than with guitars, and that's why I'm toying with the idea of trying it on a guitar.
I was thinking maybe someone here would have already tried it on a guitar, but it seems as though it's pretty rare.
I wanna try it, but I'm just at the moment trying to get as much info as I can before I slam the money on the counter.
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Quote from: IncubusI'm just kinda curious as to whether or not there would be any other benefit to balancing the output.
Me too :D
Markus
That's the thing. If you're not actually going to be plugging into a balanced input (i.e. direct into a mixing board, like a lot of bassists) then you're left with low Z out and pickup unloading (or no load on pickups) and noise reduction. The low Z out and pickup unloading can be easily accomplished with unbalanced (regular guitar) output using a single transistor or opamp. If you're really determined to stick electronics in your guitar, I'd start with that first, if you encounter noise problems with the unbalanced setup, then maybe it's time to look at an unbalanced setup.
FYI another thing to think about, if you're worried about spending $$, the Jensen transformer alone will cost you around $75.
It is plugging into a balanced input.
Quote from: IncubusIt is plugging into a balanced input.
like?
http://www.samedaymusic.com/product--BEHGI100
maybe this can be made smaller? it can work on phantom power.
Quote from: IncubusIt is plugging into a balanced input.
You're plugging direct into a mixing board or PA or some other amplifier that has a balanced input? I'm not talking about the balanced>unbalanced adapter here - as stated above, if you're ultimately plugging into an unbalanced input, what you gain over an unbalanced driver is noise protection over the balanced run. Whether that's worth the time and expense, that's up to you.
Quote from: IncubusFor example, Alembic have balanced basses.....I guess with basses it is more common than with guitars, and that's why I'm toying with the idea of trying it on a guitar.
Are you sure Alembics can come with a balanced out? I know that some models have stereo out. I have never heard of a production non-synth bass with a balanced out. I have heard of people adding one later though.
Quote from: seanmQuote from: IncubusFor example, Alembic have balanced basses.....I guess with basses it is more common than with guitars, and that's why I'm toying with the idea of trying it on a guitar.
Are you sure Alembics can come with a balanced out? I know that some models have stereo out. I have never heard of a production non-synth bass with a balanced out. I have heard of people adding one later though.
Alembic is basically a custom company - there's a few standard models, but they can put whatever you want on any of their instruments (at a price, of course).
Here's an old post at talkbass.com that talks about using a differential input active preamp to resolve 99.99% of all noise and magnetic interference issues... like, ever tried playing next to a neon sign? Bzzzzzzzzzzzzzzzzzzzzzzzzz!
http://www.talkbass.com/forum/showthread.php?t=112934&highlight=differential+input
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. And, no messing with XLR adapters to plug into your amp because you retain the unbalanced output.
...somthing I've been wanting to try for a while but, well... you know...
~ Charlie
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.
QuoteI'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
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
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.
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:
Regarding the onboard diff-amp approach, a couple things worth highlighting... I think toneman picked up on the first one...
Quote from: toneman...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
...no.
QuoteIn 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
QuoteThe 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.