# Mini to XLR



## dvlasak (Jan 16, 2008)

Ok, I've been so busy for the 3 months or so that I haven't been reading CB. A new job I have been given is to get the school AV equipment to work. One thing I want to do is to be able to plug the computer or LCD projector into any sound system. I just don't have time to make my own cable. There must be a company out there that makes mini to XLR cable. Can anyone steer me in the right direction? Thanks!!!
Dennis


----------



## Footer (Jan 16, 2008)

Does it exist, YES, should you do it, NO. Mini (3.5mm) is a stereo line level source, meaning you get 2 channels out of one cable at line level. XLR in's are mic level, which sparing you the details is a different type/level of signal. You will need to 3.5mm plug from the computer, split it into the two seperate channels, then move those to channels to a mic level signal, then into the console. 3.5mm to 1/4" TS are pretty easy to find, look at HOSA, they make them in a pretty good quality. You will then need a direct box for each channel, which changes the signal from line to mic level, these are pretty easy to come by, then you will run XLR from the direct box to your console. Now.... how far away is the computer/projector from the sound system? Is it less then about 10'... if it is and your mixer has line level inputer (1/4" usually) then you can forgo the direct box and just run the 3.5mm out to the console, going 1/4" in. 

Another option would be to get a sound card that has mic level outputs....


----------



## len (Jan 16, 2008)

Isn't there a switch on some consoles/channels that would allow line level inputs? IIRC, some smaller Mackie desks have some line level input channels.

And Radio Shack will likely have connectors that will get you from one to the other. But you'll suffer some signal loss. 

Or you could have a cable custom made. Call Bill @ ESC. It won't be that much different in price than an RS solution.


----------



## Footer (Jan 16, 2008)

len said:


> Isn't there a switch on some consoles/channels that would allow line level inputs? IIRC, some smaller Mackie desks have some line level input channels.
> And Radio Shack will likely have connectors that will get you from one to the other. But you'll suffer some signal loss.
> Or you could have a cable custom made. Call Bill @ ESC. It won't be that much different in price than an RS solution.



Most consoles will take a line level input just fine, it just depends on the distance that you are sending the line level source. Line level works fine for short distances, when you get over about 10-15' you start pushing the gear too hard. Over time, you will slowly destroy the output source. I have seen way to many computers come to me with blown sound cards because of this exact thing. Just because you can make the cable does not mean you should.


----------



## soundlight (Jan 16, 2008)

Use a Minijack to dual RCA cable and a Whirlwind PCDI (scroll down the page to find it). This works very well. While it's a large initial investment, it's well worth it to have one or two of these for an AV department. They'll take all sorts of inputs that people throw at you - computers, iPods, DVD players, VCRs, and all sorts of other random input devices that you find in an AV department.


----------



## Footer (Jan 16, 2008)

soundlight said:


> Use a Minijack to dual RCA cable and a Whirlwind PCDI (scroll down the page to find it). This works very well. While it's a large initial investment, it's well worth it to have one or two of these for an AV department. They'll take all sorts of inputs that people throw at you - computers, iPods, DVD players, VCRs, and all sorts of other random input devices that you find in an AV department.



Pretty cool product, might have to pick one of those up.


----------



## soundlight (Jan 16, 2008)

Footer4321 said:


> Pretty cool product, might have to pick one of those up.



It's one of the most useful things ever for anyone who regularly uses sources with minijack or RCA outs.


----------



## avkid (Jan 16, 2008)

soundlight said:


> It's one of the most useful things ever for anyone who regularly uses sources with minijack or RCA outs.


Yep, I love the thing to death.
That may be the one I will never sell.


----------



## avkid (Jan 16, 2008)

charcoaldabs said:


> Wait, explain the pcDI to me again?
> Line level 3.5MM (no thru) or (but not "and") stereo RCA input (with thru).
> Converts line level to mic level.
> This would allow me to plug in a line level (normal consumer audio level) to any xlr input? I can also add both left and right into a single channel.
> ...


It is not a combiner, that "hot switch" is a pad.
You can plug in any line level device, but remember that turntables require a preamp.
Buy one on eBay, they are at least $125 on Amazon.


----------



## BNBSound (Jan 16, 2008)

If stereo isn't important, which for getting Power Point or educational video out to the masses in a classroom or aud, there's a real cheap fix you can do.

Use a "Y" cable to go 1/8" mini to a pair of 1/4" and plug that into the in AND out off a direct box. The trick is to add a pair of 1000 ohm resistors to each of the 1/4" inputs inside the box. The resistors should cost about US$2 for a dozen or so at Radio Shack and you can have the mod done in about five minutes. 

While adding a resistor is not a true impedance match, it does isolate the two sides from one another, thus eliminating phasing and loss due to cancellation and attenuates the level enough to run through the DI without distorting. Also, having them in-line doesn't drastically effect the performance of the DI when being used on a single, mono source. While the lab coat types can probably quote you figures on what this actually does to the sound quality, I've been mixing for 15 years and my ears weren't able to detect any difference at all through a system. (I thought there might _possibly _have been a slight difference in the headphones). And really, what else are you going to use that thing for except to insert some low buck, poorly adjusted teenage bass player's floppy sounding rig?

While this is far from the ideal situation it does have the following merrits:

You save having to use two channels to get the stereo source to the desk.
A lot of venues and small systems are run in mono anyway, so why burn the channel?
If you have to make any number of these, it's a good deal cheaper because it cuts the number of impedance matching devices (DIs) you have to buy in half.
You could go even cheaper by using a simple in-line matcher such as the ones sold at Radio Shack for about US$15 and incorporate the resistors directly into the "Y" cables with some careful cutting and shrink wrap. (Make sure you lable them)


----------



## avkid (Jan 16, 2008)

charcoaldabs said:


> "Stereo/Mono switch for stereo operation or safely combine both inputs into a mono signal sent to both outputs"
> What is a "hot switch", what is a "pad"?
> Plus, I don't save any money by not ordering from amazon.
> $100 gift certificate + free shipping vs. 10 bucks cheaper.


One of those sets of switches is a pad and the other is a ground/lift switch.
I got mine for $65 including shipping.
You made up "hot switch" and a pad is, well look here:
http://www.uneeda-audio.com/pads/


----------



## avkid (Jan 16, 2008)

charcoaldabs said:


> I was referring to "20dB pad switch for connection to "hot" input signals". I'm not sure what that means.
> What is a ground / lift. You're sure there's no mono/stereo switch?


Do I need to go down to the basement with a camera to give you a satisfactory answer?


----------



## avkid (Jan 16, 2008)




----------



## derekleffew (Jan 16, 2008)

Sad state of affairs when I get dragged into an audio thread.

charcoaldabs said:


> I was referring to "20dB pad switch for connection to "hot" input signals". I'm not sure what that means.
> 
> What is a ground / lift. You're sure there's no mono/stereo switch?



Charc, a "pad" is used to attenuate a signal that would otherwise overdrive the input electronics due to it's intensity. Think of it as a gray, Neutral Density color filter, that lowers the signal by 20dB.

A "ground lift" in audio terms removes the connection to chassis ground from the audio signal. This can often, but not always, result in removing hum/buzz/interference from the signal. This is not to be confused with an AC Ground Lift which removes the electrical ground--those should _*never*_ be used.


----------



## avkid (Jan 16, 2008)

derekleffew said:


> This is not to be confused with an AC Ground Lift which removes the electrical ground--those should _*never*_ be used.


If you get within ten feet of me with one of those I will promptly seize it and direct toward the nearest refuse receptacle.


----------



## derekleffew (Jan 16, 2008)

I'm warning you in advance, you're not gonna like this link on "impedance matching." Bet now you wish you'd paid more attention in Algebra class, huh? Here's one more on topic.


----------



## Chris15 (Jan 17, 2008)

Avkid and others, I've looked at the photo on the whirlwind website and it has a stereo / mono switch above the ground lift switch. So my bet would be that you have an earlier version of the unit and they have since added the mix capability...


----------



## avkid (Jan 17, 2008)

Maybe they give you funny stuff in Australia.
This is the only picture on the Whirlwind site:

I'll get a hold of someone at Whirlwind and find out for sure.


----------



## Chris15 (Jan 17, 2008)

avkid said:


> Maybe they give you funny stuff in Australia.
> This is the only picture on the Whirlwind site:
> 
> I'll get a hold of someone at Whirlwind and find out for sure.


 
That would be the same picture I made my statement based upon. If you look in the lower image, there is a red rocker switch above a white rocker switch. Reading the microprint on the top above them, it's stereo / mono on the red and ground / either on or off, I can't read the print, on the white switch...


----------



## BillESC (Jan 17, 2008)

Great little box... don't leave home without it.


----------



## avkid (Jan 17, 2008)

Chris15 said:


> That would be the same picture I made my statement based upon. If you look in the lower image, there is a red rocker switch above a white rocker switch. Reading the microprint on the top above them, it's stereo / mono on the red and ground / either on or off, I can't read the print, on the white switch...


Alright, you win.
I had to turn my monitor 90 degrees to see it, and I need new glasses. 
Well then, I have a genuine vintage model!


----------



## avkid (Jan 17, 2008)

charcoaldabs said:


> Score, it sounds awesome, it's on my list. I should prioritize though. Maybe a working volt-tick is in order.


Charlie- I have a device like that, and I have used it maybe 4 times in as many years.
Get the DI, you'll love it forever.


----------



## mixmaster (Jan 18, 2008)

We do this all the time here. The stock adapter that I have is a stereo mini plug to a pair of RCA connectors. about 18" long and availble at radio shack. then an adapter that has two female RCA wyed to a male TS 1/4". this is a small plug type adapter. The 1/4" plug can go into the 1/4" jack on the board. If your board only has XLR inputs or you need to push over distances of more than the length of you adaptors, use a DI box or a barrel transformer to get to an XLR. Everything is stock off-the-shelf.
I recently built my own adapter real easy. Tip and Ring of the stereo mini plug to tip of a mono 1/4". Sleeve to sleeve. That gets you to a 1/4" plug. Transform to XLR as above. Gets you to the same place, just looks better.
Another option would be a male stereo mini to stereo female 1/4 adapter and a standard insert cable but that would burn two channels on your mixer.


----------



## Chris15 (Jan 18, 2008)

mixmaster said:


> I recently built my own adapter real easy. Tip and Ring of the stereo mini plug to tip of a mono 1/4". Sleeve to sleeve. That gets you to a 1/4" plug. Transform to XLR as above. Gets you to the same place, just looks better.



H hmm... That's a naughty way of doing things... It works, but it's naughty. You *should* have a resistor in line with each of the tip and ring off the stereo jack. 1k normally works, but a pair of anything in that sort of order of magnitude should do you fine...


----------



## mixmaster (Jan 18, 2008)

Chris15 said:


> H hmm... That's a naughty way of doing things... It works, but it's naughty. You *should* have a resistor in line with each of the tip and ring off the stereo jack. 1k normally works, but a pair of anything in that sort of order of magnitude should do you fine...



I suppose we *should* use a signal combiner to maintain impedance balance also. What I wired up though, is no different than using a stock y cable. There are no extra resistors there. Besides, have you ever tried to solder resistors to a mini plug and then get the rest of the plug back together?


----------



## Chris15 (Jan 18, 2008)

mixmaster said:


> I suppose we *should* use a signal combiner to maintain impedance balance also. What I wired up though, is no different than using a stock y cable. There are no extra resistors there. Besides, have you ever tried to solder resistors to a mini plug and then get the rest of the plug back together?



Yes and one *should* only use a Y lead to SPLIT a signal...

Wiring up said cable is easy... use 2 core shielded cable and put the resistors in the 6.5 plug...


----------



## kwotipka (Feb 2, 2008)

First, get an external sound card. If you are using a laptop, the noise that is generated within the unit is horrible. I have seen a Beringer external USB sound card (RCA Line level in and out appx. USD $30) in use without a DI or any other ground lift methods and it worked and sounded way better then the high imped. output of the headphone jack. Plus all of the extra "computer related" noise was not there.

http://www.behringer.com/UCA202/

Personally, by the time you make the cable and buy a decent DI you could most likely pick up something like the MAudio 410 on ebay.

http://www.m-audio.com/products/en_us/FireWire410-main.html

kw


----------



## Andy_Leviss (Feb 3, 2008)

mixmaster said:


> I recently built my own adapter real easy. Tip and Ring of the stereo mini plug to tip of a mono 1/4". Sleeve to sleeve. That gets you to a 1/4" plug. Transform to XLR as above. Gets you to the same place, just looks better.
> Another option would be a male stereo mini to stereo female 1/4 adapter and a standard insert cable but that would burn two channels on your mixer.



No, no, no, no, no. DON'T EVER use a Y cable to combine. EVER. Y's are only, only, I repeat only to be used to split a signal.

Here, I'll let the fine folks at Rane explain, along with circuit diagrams of how to properly combine multiple signals passively:

http://www.rane.com/note109.html


----------



## Chris15 (Feb 29, 2008)

In response to what we had discussed earlier about mono / stereo switches, I had meant to note this earlier. Whirlwind had a PC DI at Entech last month and it did have two switches, but they were two ground switches rather than a ground and a mono/stereo. Perhaps a MKIII or something?

Charlie, it's so heavy because it has transformer in it, a real one. And they are heavy. Always. The steel chassis would not be helping, but it will protect it from drop and idiots kicking it...


----------



## avkid (Feb 29, 2008)

Chris15 said:


> Charlie, it's so heavy because it has transformer in it, a real one. And they are heavy. Always. The steel chassis would not be helping, but it will protect it from drop and idiots kicking it...


I'll crack one open in a few minutes.


----------



## avkid (Feb 29, 2008)

Here you go Charlie:


----------



## howlingwolf487 (Mar 13, 2008)

The ProCo iFace is a similar box - does the same stuff the PCDI does. Your choice.

Phil...nice to see you on this forum as well.

Also, for future reference, a stereo cable (TRS, 1'8", etc.) is a balanced cable BUT NOT if it is used in a stereo configuration. In stereo usage, the left signal is usually on the tip and the right signal is usually on the ring; the shield is shared between the tip and ring. Thus, there is not a positive leg, negative leg, AND a separate shield for the signal, it is not balanced.

Search Terms for the day: Common Mode Rejection Ratio, Balanced Cable, Unbalanced Cable


----------



## DavidDaMonkey (Jul 21, 2008)

Footer4321 said:


> Most consoles will take a line level input just fine, it just depends on the distance that you are sending the line level source. Line level works fine for short distances, when you get over about 10-15' you start pushing the gear too hard. Over time, you will slowly destroy the output source. I have seen way to many computers come to me with blown sound cards because of this exact thing. Just because you can make the cable does not mean you should.



Can you explain more of this from a technical standpoint? About the sound cards frying and blowing the output source? It sounds very interesting, and is something I've never heard about.


----------

