rgr@m10ux.UUCP (Duke Robillard) (02/04/88)
Here's a question for a novice electronics and novice music type: Do turntables put out the same audio signal as electric guitars? what about really old turntables (I think they're called ceramic, as opposed to electronic), the kind that need a preamp? Can I hurt anything by pluggin a guitar into a home stereo amp? thanks.. -- | Duke Robillard | m10ux!rgr@ihnp4.UUCP {any biggy}!ihnp4!m10ux!rgr | When my time comes, that's how I wanna go, | Stoned and fat and wealthy, and sitting on the bowl...
lisper@yale.UUCP (Bjorn Lisper) (02/08/88)
In article <502@m10ux.UUCP> rgr@m10ux.UUCP (Duke Robillard) writes: > >Here's a question for a novice electronics and novice music type: > >Do turntables put out the same audio signal as electric guitars? >what about really old turntables (I think they're called ceramic, >as opposed to electronic), the kind that need a preamp? Can I >hurt anything by pluggin a guitar into a home stereo amp? Plug your guitar into "AUX" at your amp. I've been doing this with various keyboards when I've been playing with them at home and it works just fine, so I guess a guitar would be no problem either. You will perhaps need a connector adapter since your amp might not have teleplug jacks. Do not use the turntable inputs. Not that I think you can destroy anything but this input has a special preamplifier that compensates for the kind of frequency response a turntable pickup has. This will destroy, if not your amp, the sound of your guitar. And yes, switch your amp to mono (most stereo amps have a switch for that). Then you will get the sound in both channels. Some stereo amps doesn't like when they have a full signal in one channel and none in the other. Good luck! Bjorn Lisper
gary@ism780c.UUCP (Gary Swift) (02/09/88)
In article <22670@yale-celray.yale.UUCP> lisper@yale-celray.UUCP (Bjorn Lisper) writes: >In article <502@m10ux.UUCP> rgr@m10ux.UUCP (Duke Robillard) writes: >> >>Do turntables put out the same audio signal as electric guitars? > >Plug your guitar into "AUX" at your amp. I've been doing this with various >keyboards when I've been playing with them at home and it works just fine, Were your keyboards (pre)amplified? I've tried this with a (nonamplified) electric guitar and it didn't work, but it *did* work by going through turntable inputs. I don't remember the sound quality though. My experience is that the signal from an electric guitar, a microphone, and a phonograph are similar. (Hmmm, I wonder if you could plug a microphone into the phono jack?) The easiest way I've found to play an electric guitar through a stereo system is to plug it into the mic jack of a tape deck, put the deck on record, and hit the pause button (unless you want to actually record what you play). You can put special effects boxes between the the guitar and the tape deck too. With the right "Y" cables, plugs, adaptors, etc., and a second tape player, you can construct a rudimentary "recording studio" capable of mixing and overdubbing. Special attenuating cables allow you to pipe the (amplified) output signal from one tape deck into the mic jack of another. Otherwise, you need to play the first tape through the speakers and rerecord onto one track of the second tape via microphone. This method looses a lot of fidelity with each generation though; about three is the limit. -- I alone am responsible for my opinions. Gary Swift, INTERACTIVE Systems Corp., Santa Monica, Ca., (213) 453 8649 sdcrdcf!ism780c!gary
lisper@yale.UUCP (Bjorn Lisper) (02/10/88)
In article <8948@ism780c.UUCP> gary@ism780c.UUCP (Gary Swift) writes: >In article <22670@yale-celray.yale.UUCP> lisper@yale-celray.UUCP (Bjorn >Lisper) writes: >>In article <502@m10ux.UUCP> rgr@m10ux.UUCP (Duke Robillard) writes: >>> >>>Do turntables put out the same audio signal as electric guitars? >> >>Plug your guitar into "AUX" at your amp. I've been doing this with various >>keyboards when I've been playing with them at home and it works just fine, > >Were your keyboards (pre)amplified? I've tried this with a >(nonamplified) electric guitar and it didn't work, but it *did* >work by going through turntable inputs. I don't remember the >sound quality though. My experience is that the signal from >an electric guitar, a microphone, and a phonograph are similar. >(Hmmm, I wonder if you could plug a microphone into the phono >jack?) Hmm, my experience is from a Farfisa electric organ (yeah, the good old one) and DX7. Both run well through guitar amplifiers as well as through AUX. From this I assumed that a guitar probably also would sound fine through AUX. Apparently I was wrong. Bjorn Lisper
jeffw@midas.TEK.COM (Jeff Winslow) (02/11/88)
In article <502@m10ux.UUCP> rgr@m10ux.UUCP (Duke Robillard) writes: >Do turntables put out the same audio signal as electric guitars? Not if you put on a Beethoven symphony, they don't. couldn't resist... Jeff {who knows?} Winslow PS. Followups have been redirected to talk.bizarre.
todd@uop.edu (Dr. Nethack) (02/11/88)
As I recall upon occasion you can blow out your stereo doing this. The impulses from the guitar can be coarser than the input from a more balanced recording.. my friend Tim wasted a good stereo by plugging in his guitar, if you use moderation you will most likely not have this problem.
dmt@mtunb.ATT.COM (Dave Tutelman) (02/11/88)
In article <8948@ism780c.UUCP> gary@ism780c.UUCP (Gary Swift) writes: >In article <22670@yale-celray.yale.UUCP> lisper@yale-celray.UUCP (Bjorn Lisper) writes: >>In article <502@m10ux.UUCP> rgr@m10ux.UUCP (Duke Robillard) writes: >>> >>>Do turntables put out the same audio signal as electric guitars? >> >>Plug your guitar into "AUX" at your amp. I've been doing this with various >>keyboards when I've been playing with them at home and it works just fine, > >Were your keyboards (pre)amplified? I've tried this with a >(nonamplified) electric guitar and it didn't work, but it *did* >work by going through turntable inputs. I don't remember the >sound quality though. Probably deficient in highs. See discussion below. SOURCE SIGNAL LEVEL EQUALIZATION Turntable 1 mv RIAA Mike 1 mv None Guitar pickup 1 mv None Keyboard 100 mv None Tape Deck 100 mv - 1 v None In terms of LEVEL alone, the turntable input should handle mikes and guitar pickups, since they have the same output level as turntables (to within an order of magnitude, which is all the table above claims to represent). Keyboards do well into the AUX input, because it is designed for devices like tape decks and CD players (typically around a volt). However, level alone doesn't tell the whole story. When records are cut, they are PRE-EQUALIZED (high frequencies emphasized). When played back, they must be POST-EQUALIZED (inverse operation, de- emphasize high frequencies). The reason is to implement a primitive noise reduction technique. The specific emphasis curve is specified by the Recording Industry Association, and is referred to as the RIAA equalization curve. Now the catch: ALL PHONO PREAMPLIFIERS CONTAIN RIAA POST-EQUALIZATION, since they're intended for playing back RIAA-equalized source material. That means that if you play back your mike or guitar through the turntable input, you'll get exactly the RIAA de-emphasis curve cutting your high frequencies. A couple of ways to deal with this: - Pre-amplify the signal separately, and feed to AUX IN. - Put the signal through a simple (passive, homemade) RIAA pre-emphasis approximation, then play back through you phono input. My guess is the pre-emphasizer is two resistors and a capacitor, though I haven't worked the values. - Live with it. Some singers will sound more mellow with a low-pass filter. (Most rock guitars will sound better with an extreme low-pass filter ;-) +---------------------------------------------------------------+ | Dave Tutelman | | Physical - AT&T - Lincroft, NJ | | Logical - ...ihnp4!mtuxo!mtunb!dmt | | Audible - (201) 576 2442 | +---------------------------------------------------------------+
mbe@dde.uucp (Martin Berg) (02/12/88)
In article <502@m10ux.UUCP>, rgr@m10ux.UUCP (Duke Robillard) writes: > Do turntables put out the same audio signal as electric guitars? > what about really old turntables (I think they're called ceramic, > as opposed to electronic), the kind that need a preamp? Can I > hurt anything by pluggin a guitar into a home stereo amp? Hmm - depends on how you play the guitar :-). Ok, ok no more bad jokes. With modern amplifiers it may cause some problems if you connect the guitar to the turntable (phono) input. - The guitar normally produces an signal more than 10 times stronger than the signal from a turntable. The volume control on the guitar may solve this. - The turntable input has also what they call RIAA-equilization ie: the bass is amplified a lot more than the treble. This does not sound very good. You may 'correct' this by turning the bass control down and the treble up. (and you may not - depends on the amplifier). In this case you will get better results by using an AUX- or TAPE-input. With an old amplifier with 'ceramic' input it may be a little easier: - These inputs are not so sensitive [as 'modern' dynamic inputs] ie: It will not make so much noise. - You may still need to mingle with the bass and treble controls. With some care (turn the volume on the amplifier down !) you should be able to connect the guitar to the amplifier. If something starts to make a lot of noise: DISCONNECT FAST ! Generally (normally) you will not destroy anything if you don't play with a distorted sound, ie: *TO LOUD* (most HiFi-speakers don't like this - and damage is endeed possible this way). -- Martin Berg Dansk Data Elektronik A/S, Herlev, Denmark E-mail: mbe@dde.UUCP or ...!uunet!mcvax!diku!dde!mbe
jku@kolvi.hut.fi (Juha Kuusama) (02/12/88)
In article <502@m10ux.UUCP> rgr@m10ux.UUCP (Duke Robillard) writes: > >Do turntables put out the same audio signal as electric guitars? >what about really old turntables (I think they're called ceramic, >as opposed to electronic), the kind that need a preamp? Can I >hurt anything by pluggin a guitar into a home stereo amp? ... The principle of turntable pickup and a guitar pickup have slight resemblance; i.e. varying magnetic field generates voltage to a coil, but no, plugging a guitar into pickup input of a hi-fi won't work and yes, if you do that, something is likely to get broken. Explanation: The signal from a turntable pickup is about 2-5 mv amplitude. The records are created with what is called an RIAA equalisation. The amp input is designed to handle that kind of signal; it amplifies it heavile and adds a heavy bass boost. If you plug there an electric guitar, you are likely to break at least your speakers. The signal from guitars are from 40mv to 6-7 v amplitude (depending from the particular guitar). On a pickup input it will get overamplified and bass- boosted so, that it is very likely that your amp puts out more than it's rated output to your speaker. Smell smoke? Ok, when you have bought new speakers, try experimenting further. The signal from a guitar is typically 100-200 mv, high impendance, very like a tape deck puts out. So, from my experience, when you plug a guitar to a tape or aux input, it will work, but sound really bad. Plunk, plunk, twang... The guitar amps do their own heavy equalisation (here is why different brands do sound different!), usually you need some effects et.c. but if you are desperate, you may try aux input of your deck. -- Juha Kuusama, jku@kolvi.UUCP ( ...!mcvax!tut!kolvi!jku )
abeles@nvuxj.UUCP (J. H. Abeles) (02/16/88)
In article <1165@mtunb.ATT.COM>, dmt@mtunb.ATT.COM (Dave Tutelman) writes: > Probably deficient in highs. See discussion below. > > SOURCE SIGNAL LEVEL EQUALIZATION > > Turntable 1 mv RIAA > Mike 1 mv None > Guitar pickup 1 mv None > Keyboard 100 mv None > Tape Deck 100 mv - 1 v None > > ... However, level alone doesn't tell the whole story. When records > are cut, they are PRE-EQUALIZED (high frequencies emphasized). When > played back, they must be POST-EQUALIZED (inverse operation, de- > emphasize high frequencies). The reason is to implement a primitive > noise reduction technique. The specific emphasis curve is specified > by the Recording Industry Association, and is referred to as the RIAA > equalization curve. Now the catch: ALL PHONO PREAMPLIFIERS CONTAIN > RIAA POST-EQUALIZATION, since they're intended for playing back > RIAA-equalized source material. That means that if you play back > your mike or guitar through the turntable input, you'll get exactly > the RIAA de-emphasis curve cutting your high frequencies. The reason for equalization is as follows, according to my belief: When the grooves in a record contain equal amplitude fluctuations for both lower and higher frequencies, the magnetic coil pickup will emphasize higher frequencies. The factor will be proportional to frequency, because the faster the coil moves, the larger the voltage that is generated. Thus, some kind of equalization is needed to reduce the high frequency response. The RIAA curve is chosen to approximate the opposite (i.e., a rolloff proportional to freqency). Its several 3 dB break points are chosen to approximate this 1 over omega rolloff. A single pole filter is 1 over omega in voltage but I think not in power, or something like that. Thus, guitar pickups ought to require equalization as well since they work according to the same physical principle. Comments? (Am I all wrong about this?) --Joe Abeles
janpo@leffe.UUCP (janpo) (02/16/88)
In article <8948@ism780c.UUCP>, gary@ism780c.UUCP (Gary Swift) writes: > In article <22670@yale-celray.yale.UUCP> lisper@yale-celray.UUCP (Bjorn Lisper) writes: > >In article <502@m10ux.UUCP> rgr@m10ux.UUCP (Duke Robillard) writes: > >> > >>Do turntables put out the same audio signal as electric guitars? > > > >Plug your guitar into "AUX" at your amp. I've been doing this with various > >keyboards when I've been playing with them at home and it works just fine, > > Were your keyboards (pre)amplified? I've tried this with a > (nonamplified) electric guitar and it didn't work, but it *did* > work by going through turntable inputs. I don't remember the > sound quality though. My experience is that the signal from > an electric guitar, a microphone, and a phonograph are similar. > (Hmmm, I wonder if you could plug a microphone into the phono > jack?) > > I alone am responsible for my opinions. > Gary Swift, INTERACTIVE Systems Corp., Santa Monica, Ca., (213) 453 8649 > sdcrdcf!ism780c!gary Signals from phonograph and a microphone or electric guitar are certainly not the same. The phono signal needs a so called RIAA correction network in the amplifier. On a record, the bass signals are attenuated and the high tones are emphasized. Consequently, when the record is played the bass tones have to be boosted and the high tones have to be attenuated. Why this is done? Well, the strong bass tones (I.e. drums) cause wide tracks on the record which reduces the time available for music on the record. That's why collection albums with many songs on it sound so awfull and Stings' latest album (Think it's called "Bring on the night"), a two record set actually, which has only a few songs on it has a very good bass. The high tones are to reduce the high pitch noise inevitably associated with vinyl records. For those who are interested in it: The RIAA curve has two poles at 3180 /us (50 Hz) and 75 /us (2122 Hz) and a zero at 318 /us (500 Hz). What do you get when you plug a microphone into a phono jack? Well, the bass will boosted by about 20 dB over the midrange frequencies giving bangs and booms and thuds and thunders through your speaker when the microphone is only slightly touched and your voice will sound very dull. You can guess now that an electric guitar will not sound very naturally when connected to a phono input. A real microphone input will work well I think because the guitar pick-up element and a dynamic microphone both work basically the same way and without any frequency compensations.
lae@pedsga.UUCP (02/19/88)
In article <2514@midas.TEK.COM> jeffw@midas.UUCP (Jeff Winslow) writes: >In article <502@m10ux.UUCP> rgr@m10ux.UUCP (Duke Robillard) writes: > >>Do turntables put out the same audio signal as electric guitars? > >Not if you put on a Beethoven symphony, they don't. > >couldn't resist... > After observing that the signal amplitudes were about the same I used to plug a pickup into the tape inputs of my stereo when I wanted to record from my acoustic. It worked just fine, and no damage to the stereo occurred. Some turntables put out a lower power signal-- if you need a preamp you have one of them. You should have no problem plugging it into a guitar amp. -- *********************************************************************** * Testing .signature... * * 1 2 buckle my shoe * ***********************************************************************
root@mfci.UUCP (SuperUser) (02/19/88)
I believe that the problem with playing guitars through stereos is that stereos are designed to handle pre-recorded music, which means that the dynamic range is (by definition) limited. (Somewhere along the way, the music went through some compression.) The power handling capability of the amplifier, and especially the speakers, is defined on that compressed source. Guitars put out a much wider range, both in peak-to-peak voltage, and in harmonics, particularly the 2nd and higher ones. This combines to beat up your midranges and tweeters much more than they are used to. To wit: you may be playing very nicely, but catch your pick on a string and kiss your tweeter goodbye. Pre-recorded music tends not to do this. Besides, you don't want clean amplification for an electric guitar. That warm fuzzy jazz sound typically needs some 2nd harm. distortion. Bob Colwell mfci!colwell@uunet.uucp Multiflow Computer 175 N. Main St. Branford, CT 06405 203-488-6090
hg@clinet.FI (Janne H{gglund) (02/22/88)
In article <1053@uop.edu> todd@uop.edu (Dr. Nethack) writes: >.....my friend Tim wasted a good stereo by >plugging in his guitar, if you use moderation you will most likely >not have this problem. Well, I think he just discovered the 'blow your speakers' -effect... :-) But, to be more serious, home stereos that are not so anxious to blow up can be used creatively. My friend has bought a bass some time ago but does not yet have an amp. So he practises by plugging it into his tape deck and pressing "record" and "pause". What is beautiful in this setup is that when he turns the record level way up past the distortion point it gives a beautiful Judas Priest-type almost pure square-wave distortion. It's kinda weird with a bass, but when you plug in a guitar... WOW!! I think the best musical gimmicks are discovered by accident. Me, I almost blew up my best earphones when I discovered that too-low-impedance earphones in the phones-jack of my synth give diabolic high-frequency boosting distortion... %-} -- MACHINE: hg@clinet.UUCP FACE: PERSON: Janne H{gglund ( { = a + " ) ///\\ REIGN: Helsinki, Finland //. .\\ PHONE: +358-0-723173 /|| ! ||\ PHILOSOPHY: If you can't make it a classic, /|| -'|\\ forget about the whole thing! //|\ /\|\ [ Limit the lenght of our .signature -files ] [ and the next step will be concentration camps ]
dave@onfcanim.UUCP (Dave Martindale) (03/04/88)
In article <306@nvuxj.UUCP> abeles@nvuxj.UUCP (J. H. Abeles) writes: >The RIAA curve is chosen >to approximate the opposite (i.e., a rolloff proportional to freqency). >Its several 3 dB break points are chosen to approximate this 1 over >omega rolloff. A single pole filter is 1 over omega in voltage but >I think not in power, or something like that. Magnetic phono cartridges basically respond to velocity. If you cut records so that the cartridge output was flat, the *amplitude* of the groove modulations would drop by a factor of 2 per octave. The low frequencies would be untrackable and the highs would be buried in noise. If you apply a 6 dB/octave boost in recording and the reverse in playback, you are now producing a groove whose amplitude is constant with frequency. This is much better, and also works nicely with ceramic cartridges, which are amplitude-responding. Unfortunately, the 10-octave range of input signal requires a 60 dB boost/cut of the the high frequencies with respect to the low, and you want a 60 dB dynamic range for the music on top of that - that's asking a lot of the electronics. To reduce this problem, the RIAA characteristic reverts from constant-amplitude to constant-velocity for about 2 octaves in the middle of the range (0.5 - 2 KHz?). This produces the "shelf" in the equalization curve.