very interesting...

  • Thread starter Thread starter GuitardedMark
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GuitardedMark

GuitardedMark

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When I plug the line out of my guitar head to the input of my new E-Mu 0404 usb white, I dont get any sound unless I unplug it until it is loose in the jack and then it works fine. However, if I use the same cable and plug my keyboard output to the same input it works. It also works great when I plug a guitar straight in. This behavior is identical with both inputs.

I'm totally stumped with this. It just doesn't make sense. Help?
 
It's working unbalanced via the 'other' leg of the balanced input, but not being passed when the TS jack is all the way in (I assume you're using a regular mono 1/4" guitar lead).

My guess is that some behaviour of one unit (possibly design-intended behaviour in your current configuration) is tripping some kind of protection in the other.

If you have the 0404 phantom power turned on try turning it off!
 
You are plugging an unbalanced line out into a balanced line in. In most cases this should not be a problem, however I have had problems in the past where by the ring to shield link that happens at the unbalanced connection also shorts the audio via the mains earth due to designs within the equipment, i.e. audio positives on ground not negative as usual.

Try using a balanced cable, tip ring sleeve, instead of the unbalanced instrument cable you are using. The unbalanced cable should switch the ring sleeve link to the other end and may just act differently due to the plug being and unbalanced socket at the amp line out end.

If this does not work you may need an isolation box inline like this, they use earth lift balancing transformers that fix earth loops and balance unbalanced lines.

Cheers

Alan.
 
Hey guys, thanks for the response.

I must admit I'm slightly confused. Phantom power is not on. I'm using a general 1/4 to 1/8 aux cable to connect the amp and the guitar. Is there like a 1/8 to XLR male cable that I could use and would this be a good idea? I couldnt find a balanced 1/8 to 1/4 :(
 
Is my only option the isolation box? I read somewhere else that I could use a converter that switched the jack 180 degrees or something. What are my options to resolve this?
 
Whenever I have problems like this, I grab this container of alligator clip jumper cables I got from Radio Shack and use them to figure out WTF is going on. Mock it up.

The very fact that you can get it going by pulling the plug out tells me you don't need anything but a cable that is wired right.

You can theorize what's correct but the jumper cables will tell you right in your face what's up with that quirky reality stuff. I use them all the time.
 
dintymoore said:
Whenever I have problems like this, I grab this container of alligator clip jumper cables I got from Radio Shack and use them to figure out WTF is going on. Mock it up.

The very fact that you can get it going by pulling the plug out tells me you don't need anything but a cable that is wired right.

You can theorize what's correct but the jumper cables will tell you right in your face what's up with that quirky reality stuff. I use them all the time.
Click to expand...

Sorry Dinty you lost me on that. Can you simplify for me? What are jumper cables?
 
OK - this is looking less weird. You are plugging a left/right stereo (or twin mono) output into a balanced mono input, so it sums to nothing! With a different lead it will be fine.

Exactly what patching you need depends on whether the aux output from your amp is in stereo or twin mono. Either way, you need one of these. Plug both jacks into the two 0404 inputs if the aux out is stereo (say if the amp has a dsp for chorus, ambience etc), else just patch one jack for mono.

The way I'd patch it from leads I have lying around is I'd take one of those leads you use to plug an iPod into a Hi-Fi - [1/8" stereo plug to 2xRCA plug] and I'd put RCA to 1/4" jack adaptors on the two RCA plugs. Or you could use an insert lead with a 1/4" TRS to 1/8" TRS adaptor on the amp end. Or if soldering a mono lead for yourself, take a 1/8" TRS plug. leave the ring isolated, connect the T & S to a 1/4" TS plug.

Make sense?
 
GuitardedMark said:
Sorry Dinty you lost me on that. Can you simplify for me? What are jumper cables?
Click to expand...

My way would be more for if you want to learn about this stuff and get into soldering (if you aren't already).

The Radio Shack cables are small wires with alligator clips on the end: http://www.radioshack.com/product/index.jsp?productId=2062622

What I'd do is plug a plug into the jack (in this case from what I understand you have a balanced jack on your E-Mu. I mean just a plug, a stereo one like this:
http://www.google.com/imgres?imgurl...yuCA&esq=1&page=1&ndsp=27&ved=1t:429,r:17,s:0

And then I'd take the regular unbalanced guitar cable you were using from the line out of your amp and start attaching the jumper cables from the cable's plug to the plug stuck in the Emu. I'd have the system running and see what actually worked. There's a diagram here http://www.rane.com/note110.html and if you go down near the bottom to wiring diagrams 9, 11 & 14 you'll see some possibilities. In your case it sounded like the tip and ring connectors need to be swapped.

Then when I figured it out I'd make a cable or maybe short adapter for it. It seems odd you have to go through all of this - I would try a few other cables first and make sure they are standard good plugs 'cause I have had cheap plugs that were actually physically different from Switchcrafts and Neutriks. It doesn't seem right that you need to do what you're going through.
 
By the way, my suggestion above doesn't explain why the lead you have does work with your keyboard. But I'm more puzzled that it does work with the keyboard than I am about it not working with the amp!
 
dintymoore said:
My way would be more for if you want to learn about this stuff and get into soldering (if you aren't already).

The Radio Shack cables are small wires with alligator clips on the end: http://www.radioshack.com/product/index.jsp?productId=2062622

What I'd do is plug a plug into the jack (in this case from what I understand you have a balanced jack on your E-Mu. I mean just a plug, a stereo one like this:
http://www.google.com/imgres?imgurl...yuCA&esq=1&page=1&ndsp=27&ved=1t:429,r:17,s:0

And then I'd take the regular unbalanced guitar cable you were using from the line out of your amp and start attaching the jumper cables from the cable's plug to the plug stuck in the Emu. I'd have the system running and see what actually worked. There's a diagram here http://www.rane.com/note110.html and if you go down near the bottom to wiring diagrams 9, 11 & 14 you'll see some possibilities. In your case it sounded like the tip and ring connectors need to be swapped.

Then when I figured it out I'd make a cable or maybe short adapter for it. It seems odd you have to go through all of this - I would try a few other cables first and make sure they are standard good plugs 'cause I have had cheap plugs that were actually physically different from Switchcrafts and Neutriks. It doesn't seem right that you need to do what you're going through.
Click to expand...


Ya this is just a mess! It's been quite a struggle to get my new gear working. I want to stay away from soldering. Shouldn't there be a simple solution to this? What about those cords that I linked above. What do you guys think about that?
 
Mark - those cables you linked to are all stereo 1/4" TRS to stereo 1/8" TRS. The clever way to get one of those to work is to just plug it in half way - but you've figured that!

Bottom line: as I suggested above, buy a lead like this and just plug in one of the 1/4" plugs.

Surely that's not too sciency?

That said, if you want to be a real Recording Guy you need a crusty soldering iron with knots and burns in the cable, a torn plastic bag full of random old leads with occasional ends missing, and a tupperware box full of orphan audio plugs & kooky adaptors...
 
robdean said:
Mark - those cables you linked to are all stereo 1/4" TRS to stereo 1/8" TRS. The clever way to get one of those to work is to just plug it in half way - but you've figured that!

Bottom line: as I suggested above, buy a lead like this and just plug in one of the 1/4" plugs.

Surely that's not too sciency?

That said, if you want to be a real Recording Guy you need a crusty soldering iron with knots and burns in the cable, a torn plastic bag full of random old leads with occasional ends missing, and a tupperware box full of orphan audio plugs & kooky adaptors...
Click to expand...

Thanks Rob! My company firewall has blocked that site you linked :( Is there a specific product I can google to get more info?
 
lead.jpg


European units! 3.5mm = 1/8", 6.35mm = 1/4"...

...the link was to eBay where it's listed as: "6.5' Twin Male 1/4" Mono Jack to Stereo 1/8" 3.5mm Jack"
 
robdean said:
lead.jpg


European units! 3.5mm = 1/8", 6.35mm = 1/4"...

...the link was to eBay where it's listed as: "6.5' Twin Male 1/4" Mono Jack to Stereo 1/8" 3.5mm Jack"
Click to expand...

Can I ask why this would help me? I dont need stereo and isnt this the same as the ones I linked?
 
GuitardedMark said:
Can I ask why this would help me? I dont need stereo and isnt this the same as the ones I linked?
Click to expand...

I don't see if that will work. In that pic, see how two of the cable plugs are 1/4" and the other 1/8"? They're labeled 6.5 and 3.5 mm. From what I understand you have no 1/8" (3.5mm) plugs in this equation.

Sure seems odd that the + input into your Emu is the ring and not the tip...

Did you try a few different cables from the amp to the Emu?
 
GuitardedMark said:
Can I ask why this would help me? I dont need stereo and isnt this the same as the ones I linked?
Click to expand...

Gee Mark, I got my tech-support mojo workin' but it just don't work on you...

...er

um...

The neatest solution is to solder a lead - as described above.

Plugging TRS left/right into TRS balanced mono is not a solution - as explained above.

The lead I suggested would help you... erm... in the manner described above. To rephrase and reiterate: it would take the right or left leg of a dual-mono left/right output and feed it unbalanced via 1/4" jack into the mono input of your 0404. It would avoid any hot signal leg being shorted, and avoid a dual-mono signal being superimposed out-of-phase. Thus bringing about effective transmission of the might and majesty of your guitar playing, rather than the sinister and enigmatic silence which gave rise to your initial distress.
 
dintymoore said:
I don't see if that will work. In that pic, see how two of the cable plugs are 1/4" and the other 1/8"? They're labeled 6.5 and 3.5 mm. From what I understand you have no 1/8" (3.5mm) plugs in this equation.
Click to expand...

Mmm... sigh... [scratches chin]... [rubs bridge of nose]...

Mark, meet your brand new tech support guru Dintymoore... y'all go ahead and spend some quality time together... I'm off back to my soldering iron...
 
dintymoore said:
I don't see if that will work. In that pic, see how two of the cable plugs are 1/4" and the other 1/8"? They're labeled 6.5 and 3.5 mm. From what I understand you have no 1/8" (3.5mm) plugs in this equation.

Sure seems odd that the + input into your Emu is the ring and not the tip...

Did you try a few different cables from the amp to the Emu?
Click to expand...

Hmmmmmm... The amp output is a 1/8 but the keyboard is a 1/4 so I use the same cable but with an adapter. Maybe thats why the keyboard works?
 
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