Keyboard to Interface through Headphone jack

[ashearer26]

First time to the forum and Newbie doesn't even begin to describe me, so you'll have to excuse my ignorance.

I'm attempting to connect my Yamaha P70 Digital Piano to my Lexicon Omega interface. The Yamaha does have MIDI IN/OUT, which I will be connecting, but I'd also like to connect it like a line level instrument. Unfortunately, it doesn't have any typical Line Outputs, just a dual headphone jack. So . . .

I hooked up a cord that has a 3.5" end (hooked up to Yamaha headphone out) and a Y with 2 TS on the other (tip plugged to Line 1 input on Omega, ring plugged to Line 2 input). Everything looked good, software (Cubase) recognized the connections, etc.

I adjusted the gains just playing a simple chord, everything sounded fine, meter didn't show any evidence of clipping.

Then I started playing . . .

Any time I hit several notes or hit the keys with even moderate pressure, the sound distorted majorly. This happened when I was just monitoring directly (not recording) when recording, and when playing back what I recorded. I double-checked the meter to make sure my gains weren't set too high and they were way fine. I turned down the gains a bit just to check, but still same result. I turned the volume way down on the yamaha and bumped the gains a little, still fuzzy and distorted. I even played a bit with the output level to my headphones, changed my headphones, all the same.

What am I missing here? In some places I've read that it's possible that the headphone jack could just be overloading the interface, other places seem to indicate that really shouldn't be possible. Some others indicate that the quality of the output from the headphone jack just isn't good enough for recording this way. I figure that I'm missing something and there's a reason that this type of connection won't work. Thoughts?

By the way, scrapping the yamaha in favor of something with real line outputs is not an option right now. Also, I realize I could connect the keyboard straight to the computer and bypass the interface if I adjust the latency, but I'm really trying to get this to work through the interface.

Thanks in advance,

Tony

 

[ecc83]

What Ho Tony!

I must confess to being a bit mystified by your problem. Yamaha do not give an output voltage spec for that kbd. Stupid people but I cannot think it capable of even 2V rms. The Omega has a line input capability of +22dBu, around ten volts rms so overload simply should not happen.

Have you tried both sets of line inputs on the interface? Can you meter the 3.5mm stereo to TS cable and ensure there are no shorts?

You could try going in via the Omega's inserts but this would require a 3.5mm stereo to 2 x TRS cable but with tip and ring connected to the big jack's rings. Can you solder? (be good to learn in this game !)

Thought occurs (only one cup o Joe so far) Try the cable as is from a phone or iThang?

Dave.

 

[Bobbsy]

Your problem sounds like a classic gain staging issue. My guess is the the headphone output of you Yamaha is too hot (even if you lower it somewhat) and that you've got your interfaced turned down to compensate so the levels look right. Trouble is, they're already clipping on the input so that any adjustment after the keyboard is just adjusting an already clipped signal.

I'd guess that the trick is to turn the headphone out of your keyboard a long way down then turn up your interface gains as much as might be necessary to got a proper level.

 

[gecko zzed]

I'd guess that the trick is to turn the headphone out of your keyboard a long way down then turn up your interface gains as much as might be necessary to got a proper level.

That would also be the first thing I'd try

 

[ecc83]

That would also be the first thing I'd try

Well, good luck! Far be it from me to dicker with Gecks and Bob but the numbers do not stack up. That headphone out should not be close to overloading the AI's line inputs.
Do the peak indicator LEDs light?

Dave.

 

[ashearer26]

Thanks ecc83, Bobbsy, and gecko! REALLY appreciate your input as I start out here in really unfamiliar waters.

Found the problem and feel like an idiot and a total newbie. I started by turning the yamaha way down and increasing the gains, but as soon as it got audible, same problem. Then I tried plugging my galaxy s6 in and streamed some music to see how that sounded. Same. Adjusted phone output and gains, same. So this got me thinking about the distortion happening on the monitoring end (my monitors or studio phones haven't arrived yet, so I've been monitoring exclusively through cheaper headphones that I had quick on hand).

Turns out that these headphones caused the distortion, I think because they have a button wired in for skipping tracks, etc. For some reason, that was distorting the sound. Most consumer headphones have those buttons nowadays, so when I tried multiple headphones, I ended up with the same result. However, when I played the recording back through the computer's sound card, it sounded fine. I even plugged my son's $10 spiderman headphones in (that don't have one of those "buttons" wired in) and it sounded fine, no distortion.

Really simple thing, I know, could have been avoided if I had just waited for the right equipment, but I was just too anxious to get going.

Thanks for your replies and your research, sorry that it was something so idiotic on my part. Hopefully future posts (I know I'll have more questions) will be of a bit better substance and won't be so bone-headed on my part.

Thanks!

Tony

 

[ecc83]

Glad you are sorted Tone!

I know I am a pedandtic, deaf old technician but, the numbers rarely lie!

Dave.

 

[SeaGtGruff]

Wow, I'm going to add this to my stash of problems and solutions to be aware of. I haven't even seen any headphones with buttons like that-- but then, I haven't been shopping for any new headphones in several years, so I guess I'm just waaay behind the times! Anyway, I would never have suspected that your problem was caused by your headphones, and this is definitely the kind of thing I like to take note of since the cause and solution are far from obvious.

 

[Bobbsy]

Glad you are sorted Tone!

I know I am a pedandtic, deaf old technician but, the numbers rarely lie!

Dave.

Good numbers don't lie but I learned many years ago not to trust so-called specifications on pro-sumer gear.

 

[ecc83]

Good numbers don't lie but I learned many years ago not to trust so-called specifications on pro-sumer gear.

TOTALLY agree Bob! But the speccs are so well written for the Omega that they inspire confidence and even if the Adpuff dept WAS stretching things a decibel or two the relative in and out levels should still have been compatibly.

Dave.

 

[arcaxis]

For Dave and others with a bit of electronics know how, this an adapter cable someone came up with, but lends an idea of how the switches function. I'm guessing because of the switches the sleeve ground(4) did not connect back to the interface and the ring(3) was left floating with no connection. There must be adapters for headphones like these so they could be used with conventional TRS jacks(?)
Full article.... http://www.wisebread.com/build-a-cable-to-control-your-android-phone-while-you-drive