Unbalanced or Balanced for Piezo Pickup
in [Live Sound]
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From: owen8888888 on 11 Jul 2008 15:46 I remember reading that you need an unbalanced line for a guitar with pickup used with an amplifier. Why is that? Does the pickup require this unbalanced line to amplify correctly? Any good articles on this subject? How about for a piezo microphone on an acoustic guitar? Shouldn't a balanced line work just as well or better than an unbalanced line?
From: jakdedert on 11 Jul 2008 16:33 owen8888888(a)yahoo.com wrote: > I remember reading that you need an unbalanced line for a guitar with > pickup used with an amplifier. Why is that? Does the pickup require > this unbalanced line to amplify correctly? Any good articles on this > subject? > > How about for a piezo microphone on an acoustic guitar? Shouldn't a > balanced line work just as well or better than an unbalanced line? > A guitar requires an unbalanced line because that is the sort of output it has...likewise for guitar amp inputs. Balanced or unbalanced 'could' be used, but unbalanced 'is' used. IOW, it 'could' be balanced...but it's not. Even if you managed to plug your guitar into a balanced input, it would become unbalanced unless a transformer or active circuitry was used. Googling 'balanced audio signal' brings up 345,000 hits, the entire first page of which looks relevant. jak
From: owen8888888 on 11 Jul 2008 17:07 On Jul 11, 4:33 pm, jakdedert <jakded...(a)bellsouth.net> wrote: > owen8888...(a)yahoo.com wrote: > > I remember reading that you need an unbalanced line for a guitar with > > pickup used with an amplifier. Why is that? Does the pickup require > > this unbalanced line to amplify correctly? Any good articles on this > > subject? > > > How about for a piezo microphone on an acoustic guitar? Shouldn't a > > balanced line work just as well or better than an unbalanced line? > > A guitar requires an unbalanced line because that is the sort of output > it has...likewise for guitar amp inputs. Balanced or unbalanced 'could' > be used, but unbalanced 'is' used. IOW, it 'could' be balanced...but > it's not. Even if you managed to plug your guitar into a balanced > input, it would become unbalanced unless a transformer or active > circuitry was used. > > Googling 'balanced audio signal' brings up 345,000 hits, the entire > first page of which looks relevant. > > jak Thanks, I understand the basic differences between unbalanced and balanced. What I don't understand is why guitars are still being made with unbalanced outputs. Is it just to stay compatible with the older unbalanced input amps or is the unbalanced line necessary for the way a pickup/amp system works? I've googled things like 'unbalanced vs balanced' and 'why unbalanced for guitar' , etc., but haven't found the answer to this particular question. Finding the relevant information is like searching for a needle in a haystack. If anyone has the relevant information and can post it, that would be appreciated. I have a Fishman Prefix Pro installed in my guitar and I've been using an unbalanced line so far. I'm wondering what is optimal for this piezo pickup system. What kind of output is it designed with? Surprisingly, the manual didn't have this information. I think I'll write them an email. Here's the manuals: http://www.fishman.com/support/documents.asp
From: Phil Allison on 11 Jul 2008 20:46 <owen8888888(a)yahoo.com> Thanks, I understand the basic differences between unbalanced and balanced. ** Shame how that is not true. What I don't understand is why guitars are still being made with unbalanced outputs. ** There is no reason to change and every reason to continue. Is it just to stay compatible with the older unbalanced input amps ** All guitar amps on planet earth have simple, unbalanced high Z inputs. Which planet are you from - pal ? or is the unbalanced line necessary for the way a pickup/amp system works? ** It ain't technically *necessary* - plus some guitars do have balanced, low Z outputs ( eg the Gibson "recording " models) but that is so you can plug one direct into the MIC input of a console in a studio. There is an XLR right on the instrument. BTW the same guitars have a normal, unbalanced outputs too - using an audio step-up transformer. I've googled things like 'unbalanced vs balanced' and 'why unbalanced for guitar' , etc., but haven't found the answer to this particular question. Finding the relevant information is like searching for a needle in a haystack. If anyone has the relevant information and can post it, that would be appreciated. ** The use of unbalanced high Z (Z= impedance) pickups and wiring on guitars is historical - it derived from the use of the high Z PU input on tube radios as the first guitar amplifiers. These inputs were provided on the back of many sets intended for use with " crystal " phono cartridges - to play 78 rpm shellac disks with. OTOH balanced lines and inputs were devised for long cable runs for low Z microphones and used only in professional sound systems, radio broadcast and recording situations. The idea that " balanced is better" is basically a myth that YOU seem to have swallowed whole. Gulp. ...... Phil
From: Eeyore on 11 Jul 2008 21:50
Phil Allison wrote: > The idea that " balanced is better" is basically a myth that YOU seem to > have swallowed whole. Balanced IS better especially for any long cable run. For guitar pickups, unbalanced is adequate though, especially as the source is 'quasi-floating'. I bet you could lose a lot of 'tone' with fewer winding on a pickup too. Graham |