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keyboard recording issue

Discussion in 'Recording' started by pob579, Dec 27, 2006.

  1. pob579

    pob579 Active Member

    Hi,
    I want to record Yamaha P-80 through Lexicon Lambda connected to a laptop with Cubase LE.
    1. I take stereo output from P-80 and connect to Line 1 and Line 2 of Lambda. Even on a low gain it gives terrible noise. Even when Volume level is turned off on P-80.

    2. When I connect the same cable to the amp Microphone INs there is no
    noise. ?!

    3. When I take L/L+R out and connect it to Guitar input (Lexicon front IN).
    There is no noise. So I can record Mono.

    I would like to know why Line In gives a noise.
    Output impedance of Yamaha P-80 is 600 Omm.

    Thanks,
    Michael.
     
  2. dementedchord

    dementedchord Well-Known Member

    can you describe the noise??? i dont own that interface but that's the way i would expect it to be hooked up... the fact that it's noisey even when the board is turned way down suggests a grnd loop or impedence mismatch or something of that ilk...
     
  3. pob579

    pob579 Active Member

    Hi,
    the noise is like no ground wire, when the board volume turned off.
    Guitar IN even on full gain gives hi hissing noise that is nice and pleasent :) (I mean the chanell is clean). And a clipping happens at less than a half gain control knob. So you will not go more than half.
    I connected two guitars with different cables (that are good on other hardware) to Guitar In - it's fine. And than I connected guitars to Line 1 and 2. The noise is here and when I touch the strings it calms down a bit.
    Reminds me amps from 70th when we had to ground amps :)

    I guess it's deffective Line 1 Line 2.
    I will try to contact Lexicon before bringing Lambda back to the store.
    I like the design and features. But I need Lines In functionning.

    !!! Oh hell... Just tried a CD player. Connected to Line 1 and 2 with simple cable. Absolutely clean sound. No noise...

    I am not getting something :) ... Guitars and keyboard works fine in amp and mixer but not in Lines of Lambda.

    May be you can guess what it could be based on given info.
    Ideally I need to use 2 inputs at a time. Bass and keyboard.
    Tomorrow will try to connect P-80 to Mike input, just for fun.
    BTW, mikes inputs are clean with a mike.

    Thanks,
    Michael.
     
  4. dementedchord

    dementedchord Well-Known Member

    is the keyboard plugged into the same physical outlet???
     
  5. Kev

    Kev Well-Known Member

    welcome to clean earth and dirty earth situations
    and why the old pro gear had
    ... fully floating differential inputs

    I just guessing here

    the mic inputs are balanced and have a degree of CMR (common mode rejection)

    the Lambada is the USB audio interface ?

    A simple transformer coupled DI box may solve all your problems.
    a 600ohm to 10kohm transformer
    I can't find a spec or drawing for the Lambda so it is a little hard to comment.

    I generally use some sort of interface box to record Synths even if they are clean directly into the interface.
    ...
    anything from a simple transformer to a dedicated Mic-pre with an instrument in and PAD ... like a GreatRiver ... just toi add a little more characture to multiple synth lines from the one machine.
     
  6. pob579

    pob579 Active Member

    I found something very "interesting".
    Nothing to do with a source (keyboard or guitars).

    1. No source connected. No cables.
    Full gain for Line 1-2 full output (head phones monitor). Absolutely no noise.

    2. TS cable is connected to Line 1 or 2. No instrument - strong noise. When touch a sleeve the noice is terrible and stronger than when touch a tip!!! Without touching tip or sleeve.

    3. XLR cable is connected. No noise at all at full volume.

    4. Guitar IN at full volume gives some parasite noise. But less than half (before clipping) no noise and is fine for clean recording.

    5. When portable CD player connected to LINE 1-2
    with simple stereo cable. No noise at full volume.
    The same with only this cable (no CD player)

    All above is applied when Lambda is connected to a laptop or to PC!!! So it's not computer grounding.

    Looks like Line 1-2 are not grounded.
    Balanced cable???
    Nonsence.
    May be for you guys it will clarify something.
    Guess, I have to contact Lexicon people.

    Your guesses?

    Thanks,
    Michael.

    I
     
  7. pob579

    pob579 Active Member

    Kev,
    you can download Lambda manual here (few megs) if you have time :) :
    http://lexiconpro.com/ProductIndex.aspx?ProductID=8

    I cannot copy paste routing diagram. It's on page 35.

    Specifications
    Microphone Inputs: (2) Female XLR Pin 2 Hot
    Input Impedance: 600 Ohms balanced
    Phantom Power: +48 Volt
    GAIN: +44 dB
    EIN: −115 dB A-weighted @ 50dB gain (150 Ohm source impedance)
    Maximum Input Level: +4 dBu
    Frequency Response: +0, −0.2 dB 20 Hz - 20 kHz, ref. 1 kHz
    THD+N: <.005%, 20 Hz - 20 kHz
    Insert Inputs: (2) 1/4" TRS
    Send Level (tip): +10 dBu maximum
    Maximum Return Level (ring): +11 dBu maximum
    Line Inputs: (2) 1/4" TRS balanced or unbalanced
    Input Impedance: 20 kOhm balanced, 10 kOhm unbalanced
    Maximum Input Level: +22 dBu
    Frequency Response: +0, −0.2 dB 20 Hz - 20 kHz, ref. 1kHz
    THD+N: <.009% A/D, 20 Hz - 20 kHz
    Instrument Input: (1) 1/4" mono jack
    Input Impedance: 1 MOhm unbalanced
    Maximum Input Level: +8.5 dBu
    Frequency Response: +0, −0.25 dB 20 Hz - 20 kHz, ref. 1 kHz
    THD+N: <.0125% A/D
    Line Outputs: (2) 1/4" TRS balanced or unbalanced
    Level: +15 dBu maximum
    Impedance: 1 KOhm
    Headphone Output: (1) 1/8" stereo jack 100 mW per channel at 50 Ohms
    MIDI Interface: 5 pin DIN connectors for MIDI in and MIDI out
    Sample Rate: 44.1 kHz or 48 kHz (determined by computer application)
    Dynamic Range: A/D (24 Bit) 102 dB typical, A-weighted, 20 Hz - 20 kHz
    D/A (24 Bit) 102 dB typical, A-weighted, 20 Hz - 20 kHz
    A/D/A (24 Bit) 100 dB typical, A-weighted, 20 Hz - 20 kHz
    Power Requirements: USB powered
    Dimensions: 6.5 x 6.7 x 3.4
    Weight: 1.92 lbs.

    35 - routing diagram.
    It's in PDF I couldn't edit the file for just sending you two pages.

    Sure you will be able to explain my issue by veiwing this.

    From Manual:
    The Instrument input uses the same recording channel as the Line 1 input;
    anything plugged into the ¼" Line 1 input jack on the back of the Lambda
    Studio will not be recorded when a cable is connected to the ¼"

    NOTE: This jack is intended for electric guitar and bass, or acoustic instrument
    pickups, not line-level signals such as the output of keyboards or a direct out from
    a guitar amplifier.
    For those, use the Line 1-2 input jacks on the back of the Lambda Studio hardware.

    <THIS last note IS impossible. So something goes wrong.>
     
  8. Kev

    Kev Well-Known Member

    have your tried the insert returns ?

    this is an unbalanced input on the ring
    at a
    " Maximum Return Level (ring): +11 dBu maximum "

    true line inputs are
    " Line Inputs: (2) 1/4" TRS balanced or unbalanced
    Input Impedance: 20 kOhm balanced, 10 kOhm unbalanced
    Maximum Input Level: +22 dBu
    "

    I would try
    unbalanced from P-80 with 6.5mm
    hot on tip
    cold on sleeve
    TO
    balance (?) into the Lambda
    hot on tip
    cold(sleeve) on ring
    ground - no connection

    the PDF is still downloading and it will take much more time - so I haven't read it yet
    I have slow net :(
     
  9. pob579

    pob579 Active Member

    >have your tried the insert returns ?
    this is an unbalanced input on the ring
    at a
    " Maximum Return Level (ring): +11 dBu maximum "

    I don't have any TRS plugs :( just TR).
    I tried Insert with regular 2 TR plugs cable - no signal

    >true line inputs are
    " Line Inputs: (2) 1/4" TRS balanced or unbalanced
    Input Impedance: 20 kOhm balanced, 10 kOhm unbalanced
    Maximum Input Level: +22 dBu "

    This what I woud like to make work without a hassle :)

    >I would try
    unbalanced from P-80 with 6.5mm
    hot on tip
    cold on sleeve
    TO
    balance (?) into the Lambda
    hot on tip
    cold(sleeve) on ring
    ground - no connection

    For that I need TRS plugs...
    BUT,
    I have 1/4 to 1/8 stereo adapters and 2 1/8 plugs cable which I can "fix"
    to made test by your suggestion.
    I'll let you know.

    >the PDF is still downloading and it will take much more time - so I haven't read it yet
    I have slow net

    This is not good :))))) (joking)

    Thanks a lot.
    Michael.
     
  10. pob579

    pob579 Active Member

    Kev,
    I tested everything what's possible and impossible :) ...

    I prepared a cable by your instructions.

    It improved the situation a lot.
    1. I tested it with Lambda connected to a PC. As sources I used bass guitar and old Roland synt (with a left out MONO).
    The result is that at 40% gain I didn't get any noise in full head phones volume and bar graph comes to yellow. It means that with this kind of clean signal a recording should be good.
    It happened with guitar or synt connected.

    2. I took a laptop with Lambda to P-80 (another room).
    At full gain and full head phone volume I had the same noise (may be a bit less) without P80 connected. And no sound, only noise with P80 connected.

    As I mentioned at the beginning Lines 1-2 are noisy just with unbalanced cables inserted without a keyb.

    So I returned to my silly situation. And as not "big" radio man I blame
    my loved Lambda.
    P80's left ch. is not Mono. In manual they say it will provide you a signal without loosing P80 quality.

    At home for P80 I use 40W amp with 2 mic inputs. When I connect unbalanced cables from P to amp. I have absolutely no noise. And it is connection to Mics IN not Line! Sure my P80 is healthy.

    Lambda is terrible just by inserting cables in Line.

    Sorry that I am torturing you :) . As a regular user I just want to understand what's going on. May be my device is defective.
    In manual they not mention any special cables or connections.

    I will contact Lexicon. If you are able to "discover" something from my tests please let me know.

    I would like to try to connect P80 to Balanced MICs ins.
    Don't have all appropriate plugs now.

    Thanks,
    Happy New Year!
    Michael.
     
  11. Kev

    Kev Well-Known Member

    this is why I tend to use various DIY interface and DI boxes into Mic inputs

    Mic inputs are balance and have the CMR ... and are often
    Fully Floating Differential inputs

    but the balanced line should also give these advantages without the need to PAD the signal down only to gain it up imediately

    I have TRS connectors to open leads
    this allows for connection to balanced and unbalanced outputs and inputs
    :)
    even if you don't know what you are doing but as long as the volume is low-ish
    you can connect any of the flying leads until you find a good signal and low noise

    some combination of units like the ground broken and some don't

    I can't know if the Lambda is faulty ... I'd need to be there to test it for myself
    but the spec does say
    " Line Inputs: (2) 1/4" TRS balanced or unbalanced
    Input Impedance: 20 kOhm balanced, 10 kOhm unbalanced
    Maximum Input Level: +22 dBu "

    all can can add is that you need some test leads as described above

    and please read the Ranes notes and the Jensen application notes that relate to instrument interfacing


    I still haven't got a working PDF for the Lambda
    twice the PDF arrived broken
    I'll change to a different downloads manager
     
  12. dementedchord

    dementedchord Well-Known Member

    kev seems like you've tried all the possibilities... seems pretty strange though have to admit...
    maybe he just needs to take it back and try a different one... stranger $*^t has happened...
     
  13. pob579

    pob579 Active Member

    I started everything from scratch. Just to see again what I can do with my Lambda.

    1. I can connect without any parasite noise 2 sources.
    Mic (to mic input) and guitar or piano to Instrument IN (front panel).

    However the manual clearly stays on "don't connect synt to Instrument In,
    it's for guitar only".

    2. I can connect a Mixer with balanced cables to Mic 1 Mic2 INs.
    Super clean. The gain is flexible.

    3. I can connect CD player to LINE 1-2.
    I HAVE ABSOLUTELY CLEAN SIGNAL.

    When stereo cable is connected to Line 1-2 there is a noise.
    When connect CD player (and it is off) NO NOISE at all.
    When press Play. I have a NICE CD sound.

    From this I can not tell that Lines IN don't work.

    But the weird Piano connection is still there.
    I will wait an answer from Lexicon. The Creators should explain how to connect two freaking cables to LINE IN.

    Thanks for your input.
    Michael.
     
  14. Kev

    Kev Well-Known Member

    as I said very early on

    grounding issues
    clean earth and dirty earth

    multiple switch mode supplies and analog supplies can give rise to these very specific but unusual problems

    dementedchord is right about saying strange stuff can happen
    and yes it would be nice to compare to another Lambda unit.

    unless this device is capable of recording four channels at once ... like an AM3 card
    I would get a couple of DI boxes ... suited to synth recording ... and then input through the XLR Mic/Line input.

    I have lots of gear and have the choice to use various methods yet and mostly do the above.
    ...
    sometimes I do use the Ai3 directly as the input is very suited to the JV1080 and I like the hyped sound of the Alesis converters.
     
  15. pob579

    pob579 Active Member

    Kev,
    I gave a last try with XV-5050.
    The same result. NOISE (in Line).
    Took Mono and connected to guitar IN. Fine.
    I sent an e-mail to Lexicon. (Didn't find phone support).
    They promptly answered for couple of questions.
    Interesting how they will explain Line IN "magic".

    I don't want less or more than Lambda in this price range. I tried M-Audio and
    didn't like it. So I exchanged it to Lambda (more feature rich).

    All what I need is recording voice or sax, playback or piano and bass.
    All this mostly will be done on one track at a time basis.
    Sure I would like to have an option to record sax and piano or bass piano.

    I will post the final result with Lambda after talk and advices of Lexicon people. I feel they will recommend to bring it to the store for an exchange.

    Thanks for your time.
    Michael.
     
  16. dementedchord

    dementedchord Well-Known Member

    while your there cop a couple of active DI's... did you try lifting the shield at the keyboard end of the cable???
     
  17. Kev

    Kev Well-Known Member

    even the XV5050 gives the same results ?

    the line on your Lambda does seem weird
    perhaps it is faulty

    the guitar input is not the best for a -10dBu to 0dBu synth

    seriously
    no matter what the outcome is with Lexicon
    I think you should consider a simple DI box
    active or passive
    for the Synths

    they can add character and give a sound that isn't available otherwise
    OR
    they can be as clean as direct

    with the advantages of the Balanced input with the CMR


    but I do hope Lexicon can fix things for you
     

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