Noisy Lounge Audio MK III Phono Preamp

Discussion in 'Audio Hardware' started by msinderson, Feb 11, 2019.

  1. msinderson

    msinderson Well-Known Member Thread Starter

    Location:
    Atlanta Metro
    Hi,

    I've had the Lounge Audio LCR MK III for about 4 years. It's paired with the Debut Carbon w/2M Red cartridge. I use Blue Jeans Cable LC1 interconnects. Up until now I've been very happy with it but recently I moved my system to a dedicated room and noticed that there is some hiss/white noise coming from the MKIII when it's on and the volume on my NAD integrated is at about 9 o'clock. This is just above typical listening levels. I never noticed it before but that may be because the old room was not as isolated (higher ambient noise level) as the new room. I've spent some time trying to identify the source by disconnecting everything and reconnecting piece by piece. The noise is still there no matter what combination of components are plugged in. The turntable is grounded so I'm certain it's not that. I removed the MK III and put my old Artcessories preamp in the chain and there is a slight hiss but not as prominent as with the MK III. The Artcessories has an adjustable gain knob and when I move it to "minus 2 db" the hiss goes away. Could the Lounge be to high a gain for the 2M Red and creating the hiss? Is this something I should be concerned about?

    Any help/suggestions most appreciated!
     
    bru87tr likes this.
  2. Fishoutofwater

    Fishoutofwater Forum Resident

    Speak directly to Lounge. I am sure they will solve your issue. Good luck
     
    patient_ot and macster like this.
  3. Benzion

    Benzion "Cogito, ergo sum" Forum Resident

    Location:
    Brooklyn, NY
    The Lounge is conservatively rated at 40 dB gain, but in reality is about 42.5 dB, as per Robert himself. The 2M series, while rated at 5.5 mV, for which 42.5 dB is kinda high to begin with (but not too serious), is widely known to often run "hot", sometimes measuring up to 8 mV, which would put it seriously over the top with your 42.5 dB gain. Perhaps that's the situation you're having. If you have one, try another cartridge with the Lounge, something in the area of 3.0 - 4.0 mV, and see if the hiss goes away. If it does - it's not the Lounge. If it stays but is lowered - perhaps it is the Lounge, and it may need some maintenance, which may be as simple as lowering the gain a bit.
     
    patient_ot likes this.
  4. patient_ot

    patient_ot Forum Resident

    Location:
    USA
    Sounds like a gain match issue as others described but I would check all grounds and connections to be sure. Does your Debut Carbon have a ground wire? I can't remember if all of them do or if they are internally grounded.
     
  5. Benzion

    Benzion "Cogito, ergo sum" Forum Resident

    Location:
    Brooklyn, NY
    It does. Integral with the RCA's.
     
  6. msinderson

    msinderson Well-Known Member Thread Starter

    Location:
    Atlanta Metro
    I do plan on contacting them.

    I don't have another cartridge to test but based on the reduction in noise when I inserted the other preamp and dialed down the gain, the noise went away. Is there a way to reduce the gain on the LCR?

    I have the turntable grounded with an external ground wire, which works fine. It's definitely not a grounding issue.
     
    Fishoutofwater likes this.
  7. patient_ot

    patient_ot Forum Resident

    Location:
    USA
    Great.

    Yes, you send it back to the maker and have them open it up and modify it for less gain.

    Take a ferrite bead/choke and place it on the ground wire near the phono pre grounding post. See if that reduces your noise issue. Cheap and worth a shot, though I suspect the main problem is gain matching to your cart.
     
  8. Mike from NYC

    Mike from NYC Forum Resident

    Location:
    Surprise, AZ
    Make sure your power cables are not close to the interconnects and try to move the pre further away from your electronics
     
    patient_ot likes this.
  9. msinderson

    msinderson Well-Known Member Thread Starter

    Location:
    Atlanta Metro
    That was one of the first things I did. I separated the turntable and pre from the rest of the components and plugged their power supplies into a different outlet. The noise is still there. I just emailed Robert asking about adjusting the gain. I'll wait for his follow up and report back.

    Thanks everyone for the help!
     
    Fishoutofwater and patient_ot like this.
  10. gguy

    gguy Well-Known Member

    Location:
    Wildomar, CA
    Is your wall wart plugged directly into the wall? Try that.
     
    patient_ot likes this.
  11. Classicrock

    Classicrock Forum Resident

    Location:
    South West, UK.
    You should run the whole system from one outlet to minimise earthing issues. What you describe is typical phono hiss when more gain is necessary to get a decent sound level. A cartridge with higher output might help. Are you getting a significant buzzing or humming that can be heard away from the speaker or noise which you can hear playing music? If not probably not a lot to worry about. Make sure your stage is well away from any transformers in other components.
     
    Strat-Mangler likes this.
  12. Budley

    Budley Forum Resident

    Location:
    TX, USA
    It sounds like you guys are troubleshooting problems normally associated with a hum while the OP is describing a hiss.

    I'm leaning towards what Benzion and patient_ot recommended chasing.
     
    Last edited: Feb 12, 2019
  13. BIGGER Dave

    BIGGER Dave Forum Resident

    Contact Morinix directly. Pretty sure he’ll get you fixed up.
     
    patient_ot likes this.
  14. patient_ot

    patient_ot Forum Resident

    Location:
    USA
    OP is already using a fairly high output cartridge, nominally spec'd at 5.5MV, but could be higher. Gain on the phono pre is 42ish dB, which is probably a tad high for that. More gain is unlikely to solve the issue.
     

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