Hi guys,

I know this is kinda newbie stuff but it's still important! So I've read and been told that you should connect line outputs to line inputs (does that make sense?).

I know that "line" is more powerful than "phono". I've heard that if you plug a "line" output into a "phono" input you can cause damage?

If someone could clarify what I should know about this so I don't break an amp or something. Amps are another thing I need to research !! Any suggestions on good websites or are you all ready to answer 'everything' I can throw at you ?

Well, firstly, dont worry about what may or may not be a "newbie" question. Its important stuff. As you quite rightly point out, connecting the wrong things together, or the right things via the wrong sockets can have disasterous results.

The first hurdle to overcome with equipment connections is that long, long ago, almost before Mikeee was around, someone called a record player, a "Phonogram" or "Phonograph" and abbreviated the name of the sockets on the back of the hi~fi (or lo~fi, in those days) to "PHONO". This labelling was good enough considering that about the only other input you got "back then" was DIN plugs, used mainly for Tape decks. DIN plugs commonly contained 5 pins in an arc (rainbow curve), or laid out like a 5 on a dice, but there were also 4, 3 and 2 pin versions of DIN. Confusing, and awkward to wire, due to often conflicting pin wiring standards.

(Un)fortunately, the nice, simple type of connector was seen as a better connector, add got nicknamed "The phono socket"....these are the connectors that we now see every day on the backs of most hi~fi gear, DJ equipment, Video recorders etc...nice round connector with one conductor around the outside edge, with a hole in the middle of an insulator, to accept a longer pin, which is the 2nd conductor.

Too avoid confusion, its best to refer to these connectors as RCA connectors, rather than their old "phono nickname"

So...on the rear of a modern disco mixer, you'll see a multitude of RCA connectors, some labelled "CD IN", some labelled "LINE IN", "AUX IN" or "TAPE IN", "MD IN". All these will be expecting to receive 775millivolts (known as "Line level") and will therefore be fine for connecting almost any audio equipment EXCEPT record decks, which only put out a fraction of the millivolts that "line level" pushes out.

On nearly all mixers you will also have the same style of round RCA connector labelled up as "PHONO" these will be for your record decks, and have a VERY sensitive circuit behind them called a "phono pre amp"...which basically "listens" to the very low signals coming from record decks.

If you plug a nice "loud" line level device into a true PHONO connector, you will get a very loud, very distorted and very painful (for both you and the mixer) sound.

Another thing to be aware of with some mixers, is that some share one set of RCA plugs for either Phono record decks, or line level devices, such as cd~decks etc. How? when the signals are so different? Well such mixers have either a push button or slide switch near the dual function RCA sockets, with which you select which level of sensitivity you want to use through that socket eg: Line Level, or Record decks. Chose carefully, and make sure to check such switches before connecting gear.

Hope that helped

On THIS forum there is another excellent selection of posts regarding connections, read and read and take it in, the most important tip I could ever give is ALWAYS make sure and then DOUBLE check your connections as connecting new gear is an exciting event even now I get the thrills with new equipment, lastly do not plug any power cables in until you have carried out the PROPER connections, try not connecting equipment on any carpeting, static is a deadly force and easily fries delicate electronics, heres the other post link

http://www.dj-forum.co.uk/index.php?showtopic=2407

Have fun

Thanks for your info so far

Ok so let me get this right:

If I plug a line output into a phono input I'll get a distorted sound?
If I plug a phono output into a line input I'll get a weak sound?

Do any of the above 2 cause damage? I assume the distortion would.

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Also as you said that :
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Another thing to be aware of with some mixers, is that some share one set of RCA plugs for either Phono record decks, or line level devices, such as cd~decks etc. How? when the signals are so different? Well such mixers have either a push button or slide switch near the dual function RCA sockets, with which you select which level of sensitivity you want to use through that socket eg: Line Level, or Record decks. Chose carefully, and make sure to check such switches before connecting gear.
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I have a DJM 300 which has a switch at the back. It has 2 connections for both phono and line for EACH channel, as well as having a switch at the back to change from line to phono or vice versa, as well as having a switch on the top of the mixer. If someone could tell me why there're so many variable here I'd appreciate it!

Youve got the right idea about distortion or weak signals if you connect low~level phono/record deck signals to line level inputs and vice versa...but imagine it several times the effect...eg: line level into Phono input = Very very very distorted...phono into line level input = not even a weak signal will be audible.

As for all the switches...on your DJM, the input selector switches on the top of each channel fader tell that channel fader to "listen to". So, at the flick of the channel 1 input switch, you could make channel 1 listen to Input A or Input B on the back of the mixer.

If youve got several cd~decks, minidisc players, tape decks etc and a couple of record decks, you might be using THIS

The 2way button "hidden" on the back of the mixer is the button which tells One pair (stereo) of input sockets whether to expect to be listening to a loud, line level input, like a CD deck, or a very quiet, phono input, like a vinyl record deck. Such switches are relatively common, since it adds flexabilty to a mixer, whos owner might need 4 line level inputs at some gigs, but needs 2 x Phono level inputs (and 2 line level inputs) at other gigs.

Such switches are usually set once (when you wire up your inputs at the beginning of a gig, and wisely left alone for the rest of the night.

Thanks for that Gary, made alot of sense .

Only question remaining now is that for the "hidden" switches at the back of the mixer it seems like I can only have it seen on one or the other? Is there some middle ground when I want to have a line and phono input to the same channel?

I thought that you might ask that but didn't want to make my above post any longer, or more complicated, in one go.

Ok, lets say that fader number one can look at either input A sockets, or input B sockets. And for example, you have an old vinyl turntable on the "A" sockets, and a CD-deck into the "B" sockets.

The "hidden" switch on the back will only effect one of the sockets eg: Socket "A" (where your vinyl turntable is plugged in). If its set to the "Line Level" option, you wont hear anything, if its set to the "Phono level", you'll hear your vinyl playing.

The input switch on the front panel of the mixer will let you choose whether the "A" sockets (The vinyl turntable), or the "B" sockets (the CD-deck) are fed thru to the fader.


Your other faders/channels will behave similarly.

Mmmmmm I'm still a bit lost.

So what's the point of the "hidden" switches at the back if you can make the channel "listen" to the phono / line inputs using the input switch on the front of the mixer?

The "hidden" switch adjusts the sensitivity of just one of the two inputs that a channel can look at... The switch on the front panel (easier to get to, several times during a show if ness) simply tells the fader which input to look at.

For example. Lets say that the "hidden" switch controls the "listening level" for socket "A".

If you wanted to plug a CD deck (line level) into socket "A" and another CD-deck into socket "B", you would set the the "hidden" switch to "LINE" rather than "PHONO". You would then be able to choose which of those two CD-decks in "heard" by that fader simply by flicking the front panel switch over from "A" to "B"

If, however, one of the above CD-decks was a vinyl turntable, you would HAVE to plug it into socket "A" AND need to set the "hidden" switch to "PHONO" rather than "LINE". Again the front panel switch would be used regularly, so you could tell the fader whether its hearing that Vinyl turntable, or the CD-deck.

...and of course the same goes for the other channel(s) on the mixer.

I understand now! It was the ONE bit that I didn't get the first time but now I do. Thanks Gary .

YES!!! You've got the hang of it.

Of course, the reason why they dont put the "hidden" switch, on the front panel of the mixer, is that you would definately not want to accidently switch it from one position to another, and treat the audience to massive static distortions, or embarrassing silence.