# Custom Adapter



## avkid (Aug 30, 2004)

I recently got a 3.mm stereo to xlr specially designed byAFAB Enterprises, 135 Industry Ave. Frankfort, IL 60423 phone: 877-229-3601, for converting stereo output on a boom box to xlr that goes directly in to the mixer! and for under $30!! yay


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## Foxinabox10 (Sep 1, 2004)

Why don't you just go from 1/8" to 1/4" which is a lot cheaper than $30?


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## avkid (Sep 2, 2004)

only have 2 1/4 inputs whereas i have 8 xlr


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## JasonH (Sep 2, 2004)

so this is a DI box of some kind?


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## avkid (Sep 2, 2004)

i don't think so , it is just a cable with a stereo jack on one end and xlr on the other


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## JasonH (Sep 2, 2004)

Hmmm, odd. 
Those are different signal levels. Line level unbalanced to mic level balanced?
hmmmmm
i think you got ripped off


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## avkid (Sep 2, 2004)

again. i am not completely sure what it is!


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## JasonH (Sep 2, 2004)

Well, I dont know what its for...
it certainly isnt for connecting a line out on a laptop/discman/whatever to a mixer

I'd use a 1/8" to to 1/4" cable, or the cheaper way, a 1/8" to RCA, then an RCA to 1/4" into the mixer.


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## avkid (Sep 2, 2004)

i have a description here :

3' Precision Low Capacitance Audio Patch Cable	
Conn1	1/8" TRS (stereo)
Conn2	XLR male
w/ mono summing resistor network


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## JasonH (Sep 2, 2004)

Hmmm, what do you intend on using it for?


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## avkid (Sep 2, 2004)

putting a jvc consumer boombox into a peavey xr-860 mixer


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## JasonH (Sep 2, 2004)

*shudder*

why?


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## avkid (Sep 2, 2004)

for when i can not get a cd player from the av coordinator


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## JasonH (Sep 2, 2004)

well
return the $30 cable
goto the pawn shop, buy a $25 cd player.......
problem solved.


not to mention that running the headphone out into a mic input is sound to sound awful. Also, I dare you to turn on the phantom power ;-P


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## avkid (Sep 2, 2004)

it was specially designed for use with that equipment
P.S. the phantom power has been on for 2 years


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## JasonH (Sep 2, 2004)

then what is the point of this thread?

What kind of board do you have?


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## avkid (Sep 2, 2004)

just telling people about the company so they have more resources to use. Peavey xr-860 (out of production)


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## JasonH (Sep 2, 2004)

Hmm, I couldnt find any info on that, but it smells like its a 8 channel powered board?

I've never seen a person run a boom box into a PA and call themselves an "Audio Engineer"


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## avkid (Sep 2, 2004)

8 channel box like mixer , i don't do that at work, i use the gemini cd-j 20s.I only use the boombox at school where we are ignored! 

End of story!!!


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## JasonH (Sep 2, 2004)

*lol* 
your not redeeming yourself with the gemini.


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## avkid (Sep 2, 2004)

damn good cd player and a 32 channel mackie which can not be operated by a moron!!!!!!!!


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## JasonH (Sep 2, 2004)

lol

now we have added a mackie. Thats a killer combo. Gemini and Mackie.


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## avkid (Sep 2, 2004)

it is a community theare alot better off than some others so leave us alone!!!!!!


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## JasonH (Sep 2, 2004)

i'm just teasing.. relax

i've got a mackie 24 channel (absolute crap) and a couple low end cd players. I'm in the same boat as you.


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## DMXtools (Sep 6, 2004)

The resistive summing network does several things.

1. It mixes the left and right channel signals to generate a mono signal to go int one XLR channel.

2. It properly matches both the headphone-out impedance of the boom box and the microphone-in impedance of the board.

3. It attenuates the headphone-level signal down to something that won't overdrive the mic-level input.

4. It gets rid of the phantom power, so it doesn't blow up the output circuits of the boombox.

I've got a home-brew version in my cable bag - I occasionally work with a performer who brings most of his backing tracks on minidisc... and wants the disc player on-stage with him. It's a very useful item.

$30 may seem like a lot - there's less than $8 in parts. But building custom cables is labor-intensive: you're paying someone to put it together for you.

John


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## avkid (Sep 6, 2004)

thanks for the explaination, i was wondering what all those words were exactly!


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## DMXtools (Sep 6, 2004)

I've noticed a tendency to put down Peavey, Behringer and Mackie gear, and to sometimes ridicule the people who use it. What makes a good audio engineer is not the pricetag of the gear you or your organization has, but what you can do with that gear. A friend of mine, Steve Albini, has a beautiful recording studio, Electric Audio, in Chicago. He's got a Neve console, a pair of Studer-Revox 24-track 2" tape machines, a collection of microphones to die for and some of the most acoustically-perfect rooms in the world. That doesn't make him a great recording engineer. What makes him great is that he could get a better recording in a garage, with a Tascam Portastudio and a pair of SM-58's, than most engineers could get if they had his fancy gear and perfect rooms. It's less about the gear than about how well you use it.

John


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## avkid (Sep 6, 2004)

finally the truth comes out , watch out lazy people with expensive equipment the motivated people with cheap equipment are coming after you!!!


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## rgsw (Sep 7, 2004)

being english I ain't got a clue what a boom box is - do you mean a snake like item?


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## avkid (Sep 7, 2004)

no, it is a consumer stereo system that looks like this : http://www.jvc.com/product.jsp?productId=PRD3602000&pathId=36


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## rgsw (Sep 7, 2004)

excuse while i'll vomit in a corner. but why does it require a specially made cable. In the UK you can get 3,5mm jack to xlr for a few quid and my personal preference is to have 3.5mm stereo to 1/2inch mono's allowing me to take out the left channel or do crazy panning effects


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## DMXtools (Sep 8, 2004)

As I mentioned, the specially-made cable matches impedances and levels, mixes the stereo output of the player to a single mono input on the board and isolates the player from the board's phantom power. On a small board with a mono PA, you might not have channels to burn and only wish to use a single input for the player.

Although my PA is capable of stereo operation, I generally run it mono. It's a choice between giving a few people in the center of the room the position information of a good stereo image or giving everybody in the room the sound of all the instruments/performers on the stage, sans position information.

John


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## Mayhem (Sep 8, 2004)

DMXtools - just a quick question for you. 

I am assuming that from your description, the summing of the stereo signal into a mono one is done by a passive resister network. If so, how exactly is this done? 

I built a summing amplifier to do this using a TL072 op amp and several resistors and caps. It works well but the only drawback is it requires a + and – 15V DC power supply. 

If the same result can be achieved through a resistor network I would be interested in learning more about it. Especially if (as it would appear) this could be housed in the plug.


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## DMXtools (Sep 8, 2004)

A purely resistive summing network is easy. The only drawback is that it has negative gain (in other words, loss). In this case (high-level headphone out to low-level mic. in) it's a good thing - it cuts the signal level down to something that won't overdrive the mic. preamps.

The particular network used would depend on the impedances and signal levels involved. I'll try to make time to draw up a couple examples and post a link to them here later today.

John


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## Mayhem (Sep 8, 2004)

Thanks - that would be very helpful as the summing amp that I put together only combines the input signals and I am lucky that my desk has been modified to include a 20db pad switch on the input attenuation.

However, this is not the case on my smaller desk.


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## Scooter (Jan 24, 2005)

i paid ten bucks for a hosa stereo mini plug to two 1/4" plugs that i use for my laptop and my iPod. it's just like a insert cable but it has a mini jack instead of a quater. i then put it into two channels on my board. but if your presssed for space you could put it through a di and have one mic line. lot cheaper. espesially if you have a di already.

pearsonally, i make all my adaptors in the schools head end room. (i do all the soldering in the boiler room though cuz theres no fire sensors there. i made good friends with the custodians. i get lots of keys too) just look up what wires connect to what on the internet.


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## avkid (Jan 24, 2005)

I have one of those Hosa adaptors and it is total garbage,it looks like someone melted RCA cable sleeves on to gold connectors they were not meant for.


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## len (Jan 25, 2005)

I suggest that $30 for that cable seems high. Next time, try http://www.entsyscorp.com They make custom cables, and usually for less, and they come with a lifetime guarantee. They use whirlwind connectors. I get all my dmx line from them. Never once had to replace one and I tend to beat on things.


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## avkid (Jan 25, 2005)

for some reason that link is dead


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## len (Jan 25, 2005)

I don't know why the link doesn't work, but I suspect it has something to do with this site. If you type it into your address line on your browser manually it works fine. 

BTW, I don't get commissions from them, but they do provide a quality product. And the owner, Bill, knows a lot of really bad jokes.

http://www.party-chicago.com
to see if it's all links or just that one.


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## avkid (Jan 25, 2005)

I typed it in and it still does not work!


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## Peter (Jan 25, 2005)

http://www.entsyscorp.com 

Try that (I think the . at the end of his sentence got into the link by mistake).


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## Mayhem (Jan 25, 2005)

DMXtools said:


> A purely resistive summing network is easy. The only drawback is that it has negative gain (in other words, loss). In this case (high-level headphone out to low-level mic. in) it's a good thing - it cuts the signal level down to something that won't overdrive the mic. preamps.
> 
> The particular network used would depend on the impedances and signal levels involved. I'll try to make time to draw up a couple examples and post a link to them here later today.
> 
> John



Hi John.

Don't you just hate it when an old post is rediscovered!

I was just wondering if there is any chance of getting these examples?

Cheers,


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## TechnicalDirector3-W (Jan 25, 2005)

There were probably better solutions to your problem than to get an adaptor of that sort made for $30.


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## cutlunch (Jan 25, 2005)

I needed to combine stereo signals from a vcr to mono, when I worked at a high school. I used the speaker to line level convertor to save channels. It is still in use after a couple of years. I could have probably also just used the simple combining circuit mentioned at the following link

http://www.epanorama.net/index2.php?section=circuits&index=audio

He also shows resistance network attenuators plus a simple passive resistance mixer.


While trying to remeber where this link was I came across a Tech Note from Rane on the subject which is quite helpful.

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


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## JahJahwarrior (Jan 25, 2005)

so if all your equipment is old, beat up, cheap and from either the 70's or walmart, you arne't an audio engineer? 

me+Peavey Series 260 amp (4 channel powered mixer, from 1975. 130 watts out, controls on each channel: volume. high. low. reverb.)+Peavey column (4x10 column speaker from 1974)+homemade green wedge speaker (12" speaker from I don't know when)+homemade speaker cables (100' extension cables cut in half with 1/4 plugs soldered on)+cheap mic and XLR-1/4TS cable, plus a guitar amp= concert 

 

I know you were just joking but seriously, a good show and a good mix can be done with very old, cheap or bad equipment. It's all good I just like to type  

and $30 does seem expensive, but sometimes when you need something to do the job, any price is a good one!


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## avkid (Jan 25, 2005)

Is that directed at me? if so, it takes a clever person to keep it all going,a lesser person would have thrown it out years ago!


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## SuperCow (Jan 26, 2005)

I think it should ba a mark of pride to do good work with poor equipment, against all the odds.


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## avkid (Jan 26, 2005)

darn right!!! The revolution is coming,the people with poor eqiupment and good attitudes are going take on the people with good equpment and bad attitudes! Viva Revolucion!!!!


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## SuperCow (Jan 26, 2005)

avkid said:


> poor eqiupment and good attitudes are going take on the people with good equpment and bad attitudes



It's not what you've got, but how you use it!


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## JahJahwarrior (Jan 26, 2005)

um, I am too lazy and tired (just spent four hours rehanging my youth group's lighting by myself, which involves moving a big lift around then hauling myself up the back "spine" becaues it's meant to be int he basket and be lifted up, not climbed up. it's a pain in the lower back  ) to look back but I think it was aimed at the dude who was making fun of you for using a mackie. it seems he was joking but w/e, you know? 

mackie 1604 VLZ-Pro really really nice board, I'm in love withit! Mackie equipment is really nice. woudlt' be good for huge live stuff but it's just beautiful for a small show. 

and I'm darn proud of my peavey stuff!  the revolution has begun! mixing fingers ready! MIX!!!!!!!


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