Mono out from a DMP2

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hairylarry

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Hi,

I use a DMP2 supposedly very similar to a DMP3. It has XLR or phone jack inputs and phone jack outputs, left and right.

What I want to know is can I make the outputs mono with a Y cable or is this likely to fry my preamp.

Thanks,

Hairy Larry
 
are you saying that you want to sum the two mono outputs to mono? i don't think a y cable would be a good idea here. you have a mixer?
 
hairylarry said:
Travis,

Yes. Guitar in one input. Vocals/harp in the other. Mono out.

I did this recording "The Junky Chevy Band" but I went to mono in post.

http://archive.org/details/junky_chevy

Thanks,

Hairy Larry

Holy shit Larry, you're the REAL thing.

If I was you and wanted to take two tracks and mix them to mono, I'd just go ahead and buy a little $50 Behringer UB802 mixer and use the two mic pres in the Behry, panned in the center, and go for it. As much stick as the Behringer mixers get, they sound a lot better than some people would like to admit. FWIW.

Anyway, I loved your blues video. Tastey harp too. ;)
 
Yeah. I'm with the Klash Kid on all his points. Cool harp! What's that guitar? An old Silvertone maybe?
 
Silvertone Guitar

Hey guys,

Thanks for the nice words.

The guitar is a Silvertone L5 made by the Gibson Guitar Company for Sears and Roebuck. I have seen other L5 guitars including a Montpelier sold by Western Auto. Oh, and my friend Suzanne Michell has the Gibson version.

The had a Gibson L5 on the Antiques Road Show and the guy gave a little history. They were made for big bands before they had amplification. Eddie Lang played one in the thirties. Mother Maybelle Carter played one.

I was in Nashville and went to the Gibson store. They had new L5 guitars on the wall for $5000.

So there's seventy years of L5 history for you.

I got mine in a pawn shop with the case for $60.

As far as a cheap mixer goes no way it sounds as good as the DMP2. And I'm trying to minimize the equipment I have to carry. Like I always tell the band about arrangements, less is more. The less I have to carry and set up the easier it is for me to go out and play.

Here's my plan. The DMP2 into a Wharfedale Pro Active 8.2. I don't think I can get less than that.

Thanks,

Hairy Larry
 
Last edited:
You want to record the two mono tracks (guitar and vocal) onto one single mono track? If this is the case, why not simply record the two mono channels to separate tracks, and mix them down to one mono track?

I apologize if I'm off base here.
 
Not recording

Hi,

I already recorded the two mono tracks to my iRiver and then mixed them in post. That's not the problem.

I want to do the same thing live.

Thanks,

Hairy Larry
 
You can split a signal with a Y cable but you can't combine two signals into one using a Y. Well, you can, but try it and see... you'll hear what I mean.
 
Direct box

ittam said:
Something like this would be the right way http://www.whirlwindusa.com/dirbox.html
Matti :)

Matti,

I assume you are talking about the Direct-JT at the top of the page with the combine feature.

I like this idea and I wouldn't mind having a quality direct box for the more traditional purposes.

But $140! Whew. Are you aware of any cheaper alternatives that won't compromise quailty?

Thanks,

Hairy Larry
 
Try it and see what?

Timothy Lawler said:
You can split a signal with a Y cable but you can't combine two signals into one using a Y. Well, you can, but try it and see... you'll hear what I mean.

Tim,

Thanks for your input. I have used Y cables at signal level splitting a signal into 2. I come off the snake into my monitors amp with a Y so both the left and right channel get signal rather than using the tricky first click method that Peavey provides. My mains amp has a mono switch so I like that better.

When you say try it and see I assume you're not saying see your preamp burn.

Do you get distortion, phasing issues, ???

Can I safely try it and see? Without burning anything up?

My rule of thumb has been that it's ok to merge signal but not ok to merge power. That is connecting both sides of a stereo amp to the same speaker is not mono bridging and can cook your amp.

But I don't trust that rule of thumb when it comes to my cheap but I love them so much preamps.

-----

I gave you a shout at myspace. For anyone who's interested my page is

http://myspace.com/hairylarryland

Thanks,

Hairy Larry
 
The one time I tried it nothing was damaged, it just sounded like there was an impedence mismatch, or an odd type of phase cancellation.
 
And the answer is

Hi,

I had to go to the big guns but here is what I found out.

I communicated with mshilarious and M-Audio tech support. Jon (mshilarious) was the most help. I asked him about using a Y cable to make the output from both channels of my DMP2 mono. He said

"Probably not directly with a Y cable, because the two channels would act
as a low impedance load on each other. You shouldn't damage anything,
but the signal will drop at least 6dB, and the quality could be
significantly degraded.

You can mix them with a special Y cable where each output is wired
across a 10K resistor. That will still lose some level, but the signal
quality should be otherwise unaffected."

When I wasn't sure what he meant by "each output is wired across a 10K resistor" he sent a little picture.

L output ---> 10K resistor --> Y cable

R output ---> 10K resistor ---> Y cable

"Nothing but ground should connect to ground.

Essentially it makes the Y cable into a basic 2 channel passive mixer.
You should be able to build the resistors into the cable connectors.
Any resistor will do."

Very helpful. He's a hell of a guy.

M-Audio was less help but they did say

"You can try it. It should not harm the preamp."

So I tried it with a regular Y cable first and it worked great. I hooked up just my guitar first and played a little bit. Then I put the Y cable on and added a microphone. The guitar sounded exactly the same. My voice was fine. I used the rig at rehearsal last night and it was the high quality acoustic guitar and vocals sound I wanted.

So I went hmmmm ... and I opened up the case.

With only one side of the board available it was kind of hard to trace but I did find a resistor connected directly to the number 2 output tip. It was only 4K but it was connected in series to a 6K. Now there is probably something else connected at that point but it does seem an awful lot like mshilarious' suggested 10K.

It appears that the DMP2 already has a resistor wired to the outputs and a regular Y cable acts like a passive mixer.

I asked M-Audio where I could find a schematic but they do not make them available to the public. I guess you have to be an authorized repair center or subscribe to a service to get their schematics.

As far as Tim's experience either he was experiencing the low impedance load problem mshilarious referred to or he was getting exactly what often happens when you mix stereo down to mono, phasing issues.

But as far as the DMP2 and probably the DMP3 (I don't have one but I wouldn't be afraid to try it) a Y cable takes the two outputs to mono no problem.

The DMP2 has balanced out and the Wharfedale has balanced in. I might try a balanced Y cable and get more gain and longer cable runs but I don't really know why I would need it.

Thanks,

Hairy Larry
 
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