My left NAD

Polk65
Polk65 Posts: 1,405
edited July 2006 in Electronics
The left channel has started to crackle then go silent after 10 minutes on. It's a model 214 and going in for repair soon.

Any known mods that can be done to it while it's on the bench?
Post edited by Polk65 on
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  • organ
    organ Posts: 4,969
    edited April 2006
    Take a look at the connections on the back of your speakers and amp. Make sure there's no short. You have to look for loose strands of wire.

    As to mods, it depends on the amp and technician. I'm not farmiliar with your model. If it's old, some parts could be updated, like caps and resistors to audiophile quality ones. But it also depends on the technician. Some don't care if they use lower quality stuff, because they fixed it and it measures up to spec. Talk to him first.
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  • cbl117
    cbl117 Posts: 285
    edited April 2006
    I have nothing to add, but nice title!:D
    2 Channel

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  • Polk65
    Polk65 Posts: 1,405
    edited April 2006
    Tried three sets of wires, same result. The terminals looked good so I checked for loose or burned caps. Nothing visible to the eye. :(
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  • Zen Dragon
    Zen Dragon Posts: 501
    edited April 2006
    Sorry to hear the amp is unhappy. :(
    If it works for 10 minutes on start-up then goes dead it is likely heat related. Either a borderline failed component or a hairline crack in a solder joint or circuit run failing as the amp heats up.
    For mods you could look into updating caps for sure, maybe resistors, RCA jacks. Caps in the signal path as well as maybe upgrading power supply/filter caps.
    If you have the schematic you could try to find some of the more critical components.
    The Family
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    Do not one day come to die, and discover you have not lived.
    This is pretty f***ed up right here.
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  • AndyGwis
    AndyGwis Posts: 3,655
    edited June 2006
    Hey guys,

    One of my two TFM-6s started to do something similar to Polk's left NAD. Before putting it in storage for about three months, there did seem to be a bit weaker output from the left side. I cleaned the inside with compressed air and wiped down the inside and outside to remove dust and then put it away for a while.

    This weekend, I pulled it out to power some outdoor speakers. The left channel doesn't have any output anymore. Speakers are fine, tried different ICs, looked around inside for shorts, bad fuses, etc. Everything looked fine to the naked eye.

    Any troubleshooting tips? The amp is not worth service. . . but I would like to mess around with it and try to fix. It's not much good to me with only one channel, and I can always just save it for parts (I have a second TFM-6) if my self-service goes wrong.

    Let me know if there's any easy troubleshooting. I don't have the schematics (where do you find them anyways?).

    Andy
    Stereo Rig: Hales Revelation 3, Musical Fidelity CD-Pre 24, Forte Model 3 amp, Lexicon RT-10 SACD, MMF-5 w/speedbox, Forte Model 2 Phono Pre, Cardas Crosslink, APC H15, URC MX-950, Lovan Stand
    Bedroom: Samsung HPR-4252, Toshiba HD-A2, HK 3480, Signal Cable, AQ speaker cable, Totem Dreamcatchers, SVS PB10-NSD, URC MX-850
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  • AndyGwis
    AndyGwis Posts: 3,655
    edited July 2006
    Working now. Turned out to be an easy fix. . . no big deal.
    Stereo Rig: Hales Revelation 3, Musical Fidelity CD-Pre 24, Forte Model 3 amp, Lexicon RT-10 SACD, MMF-5 w/speedbox, Forte Model 2 Phono Pre, Cardas Crosslink, APC H15, URC MX-950, Lovan Stand
    Bedroom: Samsung HPR-4252, Toshiba HD-A2, HK 3480, Signal Cable, AQ speaker cable, Totem Dreamcatchers, SVS PB10-NSD, URC MX-850
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  • dorokusai
    dorokusai Posts: 25,577
    edited July 2006
    I would upgrade the capacitors and hotrod the connections ala Vampire Wire. If you enjoy it, why not.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
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  • ESavinon
    ESavinon Posts: 3,066
    edited July 2006
    How useful are you with an soldering iron?

    Bring familiar with nad products specifically nad amps, i can tell you how to check for a common problem affecting their amplifiers.

    Let me know if you're willing to go inside with an soldering iron.
    SRT For Life; SDA Forever!

    The SRT SEISMIC System:
    Four main satellite speakers, six powered subs, two dedicated for LFE channel, two center speakers for over/under screen placement and three Control Centers. Amaze your friends, terrorize your neighbors, seize the audio bragging rights for your state. Go ahead, buy it; you only go around once.
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  • AndyGwis
    AndyGwis Posts: 3,655
    edited July 2006
    Okay, thanks for the responses. I have good dexterity and can get my hands on a soldering iron without a problem. I would be happy to play around with the amp.

    I did find out that it is not a dead left channel after all, but, as others have experienced with this model amp, the left channel needs a significant input signal to "wake up," at which point it plays fine. My ipod just didn't have the gain/signal strength to get it going, but my cd player did.

    What could be a possible cause? Maybe a "stuck relay" as someone on AudioReview said for this amp? How would that be fixed?


    Thanks! I am also going to try to replace some RCA input jacks on both the Carver and my B&K Pro-10MC and ST-202. Carver will be the guinea-pig, help with procuring parts and instructions very welcomed!

    Andy
    Stereo Rig: Hales Revelation 3, Musical Fidelity CD-Pre 24, Forte Model 3 amp, Lexicon RT-10 SACD, MMF-5 w/speedbox, Forte Model 2 Phono Pre, Cardas Crosslink, APC H15, URC MX-950, Lovan Stand
    Bedroom: Samsung HPR-4252, Toshiba HD-A2, HK 3480, Signal Cable, AQ speaker cable, Totem Dreamcatchers, SVS PB10-NSD, URC MX-850
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  • ESavinon
    ESavinon Posts: 3,066
    edited July 2006
    Check the relays and rca solder joints.
    Better yet,buy some silver solder, remove the old solder from the rca and relay posts,hold down the relays and rca posts firmly while applying new solder. Nad amps develop cold solder joints in both of these locations over time due to heat and high amperage.
    I had the same problem you had and solved it in this matter.
    SRT For Life; SDA Forever!

    The SRT SEISMIC System:
    Four main satellite speakers, six powered subs, two dedicated for LFE channel, two center speakers for over/under screen placement and three Control Centers. Amaze your friends, terrorize your neighbors, seize the audio bragging rights for your state. Go ahead, buy it; you only go around once.
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  • reeltrouble1
    reeltrouble1 Posts: 9,312
    edited July 2006
    Or junk the ipod!!!

    RT1
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