Page 1 of 2 12 LastLast
Results 1 to 15 of 26

Thread: Descent sub transformer noise

  1. #1
    David O
    Guest

    Default Descent sub transformer noise

    I recently purchased a Martin Logan Descent sub and have a quick question to owners. When the sub is off I hear a slight buzz from the transformer. When the sub is on the transformer noise fades and is no longer present. Is this a normal characteristic of the sub or should I be concerned? Not a ground loop. No humming just a slight internal buzz when off.

  2. #2
    Senior Member Robin's Avatar
    Join Date
    May 2005
    Location
    Calistoga, California
    Posts
    3,292

    Wink Descent Transformer Buzz...

    Quote Originally Posted by David O
    I recently purchased a Martin Logan Descent sub and have a quick question to owners. When the sub is off I hear a slight buzz from the transformer. When the sub is on the transformer noise fades and is no longer present. Is this a normal characteristic of the sub or should I be concerned? Not a ground loop. No humming just a slight internal buzz when off.
    David,

    Welcome to the ML Club!
    No, your Descent should be quiet when it is off. I had this same problem when I first got my Descent a couple of years ago. IMHO, I think it maybe a Descent power cable positioning problem. What I did was moved the Descent's power cord away from my main speaker's bi-wire cables (Ascent i's). I had to raise the Ascent i's bi-wire above the Descent's power plug, they could not touch at all. I also had to plug the Descent into a separate power circuit, not the same circuit as my Ascent i's or Theater i's power conditioner. Give it a try. It worked for me. Good luck...

  3. #3
    David O
    Guest

    Default

    Oh that's just great. A $2,600 gremlin Thx for your post Robin. I hope this is not the case. Anyone else experienced this with a Descent sub and resolved in a different manner. I only have one circuit for my home theater available. My mains lines are close to the Descent Power cord because of the limited space available in my living room.

  4. #4
    Senior Member Robin's Avatar
    Join Date
    May 2005
    Location
    Calistoga, California
    Posts
    3,292

    Thumbs up It's not as bad as all that....

    Quote Originally Posted by David O
    Oh that's just great. A $2,600 gremlin Thx for your post Robin. I hope this is not the case. Anyone else experienced this with a Descent sub and resolved in a different manner. I only have one circuit for my home theater available. My mains lines are close to the Descent Power cord because of the limited space available in my living room.
    David,

    It's just a minor tweak really.... It took me about an hour or so with my son's help of course, and presto it was gone. I've hardly thought about it since... I really love the Descent subwoofer, as I know you will soon. Hang in there. It didn't cost me anything at all I just had to position things differently that's all... I think Roberto would agree with me on this. Give it the old college try.

    HTH

  5. #5
    Taz
    Guest

    Default

    Are you sure it is not a ground loop. They sometimes will sould like a buzz. If you have not tested it I would just to be sure. Subs(amps) are known to be a cause of it.

  6. #6
    Super User roberto's Avatar
    Join Date
    Jan 2005
    Location
    San Jose, Costa Rica
    Posts
    2,910

    Red face

    Quote Originally Posted by Robin
    David,

    It's just a minor tweak really.... It took me about an hour or so with my son's help of course, and presto it was gone. I've hardly thought about it since... I really love the Descent subwoofer, as I know you will soon. Hang in there. It didn't cost me anything at all I just had to position things differently that's all... I think Roberto would agree with me on this. Give it the old college try.

    HTH
    Hola...gee, you got me here Robin...I think it is just a minor problem, and it is coming from the transformer itself. Sometimes, the plates of the transformer could be loose and this produces this kind OF buzzing...you have to find how to get to the Xformer that it is making the noise and tight the four nuts that secures the plates and the external cover...happy listening,
    Roberto.
    Last edited by roberto; 09-27-2006 at 09:07 PM.

  7. #7
    dyazdani
    Guest

    Default

    Quote Originally Posted by roberto
    Hola...gee, you got me here Robin...I think it is just a minor problem, and it is coming from the transformer itself. Sometimes, the plates of the transformer could be loose and this produces this kind fo buzzing...you have to find how to get to the Xformer that it is making the noise and tight the four nuts that secures the plates and the external cover...happy listening,
    Roberto.
    That's what I was going to say too, but couldn't understand why the X-former would buzz with no power. Is there a standby switch or something?

  8. #8
    David O
    Guest

    Default

    Not a ground loop. If so, the hum would also be present in the woofer when powered on. It would hum when the unit is on and not on standby. The amps transformer is silent when the unit is on. No hum, hiss or buzz. Perfect. Only when the amp sleeps does the transformer buzz return.

    The transformer buzz occurs when the Descent is either in standby mode or off using the power switch on the face plate. There is a master amp off in the rear. This usually stays on unless you plan to vacation.

    Robin, I plan to rearrange the power cables. Hopefully it is just picking up some transient AC line noise. I could always purchase a better shielded power cable.

  9. #9
    Junior Member
    Join Date
    Jan 2005
    Posts
    59

    Default descent

    contact Jim Powers at Martin Logan before you do anything.

  10. #10
    Senior Member Robin's Avatar
    Join Date
    May 2005
    Location
    Calistoga, California
    Posts
    3,292

    Lightbulb Descent Buzz...

    David,

    I Hope everything works out, when you reposition the power cables... As you are doing so, listen for the sound to go away when you think you have got it. When I moved the last touching point, the buzz immediately stopped...

    I was just thinking, another possibility could be fluorescent ballast or a dimmer switch on the same circuit, which your Descent maybe, unwittingly plugged into as well.... Just a thought, as these types of devices may cause the buzzing of the internal amp on the Descent.

    By-the-way ~ I just want to admit - Roberto is my personal savior, I just thought I'd admit it publicly... I love you Roberto.

  11. #11
    David O
    Guest

    Default

    I should mention that the transformer buzz can only be heard when I put my ear close to the enclosure. I could put this topic to rest if a couple of Descent owners could verify with the main amp power on (back of unit) and the front power switch off, do you hear a low buzz inside the enclosure. If not, Lexor how would one go about contacting Jim Powers at Martin Logan?
    Last edited by David O; 09-27-2006 at 06:47 PM.

  12. #12
    Taz
    Guest

    Default

    Quote Originally Posted by David O
    I should mention that the transformer buzz can only be heard when I put my ear close the the enclosure. I could put this topic to rest if a couple of Descent owners could verify with the main amp power on (back of unit) and the front power switch off, do you hear a low buzz inside the enclosure. If so, Lexor how would one go about contacting Jim Powers at Martin Logan?
    If you disconnect the sub cable does it still buzz.

  13. #13
    David O
    Guest

    Default

    Yes with or without the sub cable. When the unit is on no buzz or hum completely silent. Only when I turn the sub off do I hear the slight buzz of the transformer. Again not through the woofer but within the Descent enclosure. I thought I was just being anal, but with no confirmation from other Descent owners of a similar characteristic I wonder.

  14. #14
    Taz
    Guest

    Default

    Quote Originally Posted by David O
    Yes with or without the sub cable. When the unit is on no buzz or hum completely silent. Only when I turn the sub off do I hear the slight buzz of the transformer. Again not through the woofer but within the Descent enclosure. I thought I was just being anal, but with no confirmation from other Descent owners of a similar characteristic I wonder.
    Bummer it is the sub and it would drive me nuts to. I can not believe it is normal, someone with the Descent chime in.

  15. #15
    Super User roberto's Avatar
    Join Date
    Jan 2005
    Location
    San Jose, Costa Rica
    Posts
    2,910

    Default Just thinking loud Robin...

    Hola...just thinking loud, the problem is when the unit is in off position...the buzz is coming from the inside of the cabinet, and not from the speaker, then we might have two power supplies working inside. One is the small power supply that turns on the power amp, (big power supply) when a signal is detected at the input, high or low impedance, this ssmall xformer is the culprit of the noise. Hope this can help to track the problem...happy listening...and I love you too Robin ...
    Roberto.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •