Help with Carver TFM-25

nguyendot
nguyendot Posts: 3,594
edited December 2011 in Electronics
Just picked up a Carver TFM-25 and the left channel sounds very scratchy.

It's constant. Where should I begin?

thanks
Main Surround -
Epson 8350 Projector/ Elite Screens 120" / Pioneer Elite SC-35 / Sunfire Signature / Focal Chorus 716s / Focal Chorus CC / Polk MC80 / Polk PSW150 sub

Bedroom - Sharp Aquos 70" 650 / Pioneer SC-1222k / Polk RT-55 / Polk CS-250

Den - Rotel RSP-1068 / Threshold CAS-2 / Boston VR-M60 / BDP-05FD
Post edited by nguyendot on
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Comments

  • thsmith
    thsmith Posts: 6,082
    edited August 2009
    Most likely the power rail voltage needs to be adjusted or a transitor is hot or a cap is leaking or bulging.

    carveraudio.com forum or Rolland at Hi-Tech or Rita.
    Speakers: SDA-1C (most all the goodies)
    Preamp: Joule Electra LA-150 MKII SE
    Amp: Wright WPA 50-50 EAT KT88s
    Analog: Marantz TT-15S1 MBS Glider SL| Wright WPP100C Amperex BB 6er5 and 7316 & WPM-100 SUT
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  • treitz3
    treitz3 Posts: 19,923
    edited August 2009
    The amp needs to be serviced if you have ruled out all other components in your rig, including cables.
    ~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
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  • nguyendot
    nguyendot Posts: 3,594
    edited August 2009
    The amp is the only thing new to the setup, I simply replaced the NAD 214 with the Carver.

    I already knew it needs service, that is why I asked where to begin, otherwise it'd be working.

    My main questions were what to look for in the amp itself, such as thsmith was pointing me to. I looked inside and there are no bulging caps, none leaking or burnt. It looks like the distortion is coming from the input stage. When you turn up the volume past 1/4 or even close, the amp goes into protect mode. If I pull the left channel connection from the input stage the to amp stage, the issue goes away - no protect mode. I swapped the right channel connection to the left amplifier and it plays clean. This leads me to believe there is a bad component or connection on the input stage PCB. Since this PCB is removable I believe it should be easily serviced. There aren't that many components on it and I believe in 4hr or less anyone handy with a soldering iron can replace all the components (i am not handy with one).

    Is there something I should look for on this pcb specifically?

    thanks
    Main Surround -
    Epson 8350 Projector/ Elite Screens 120" / Pioneer Elite SC-35 / Sunfire Signature / Focal Chorus 716s / Focal Chorus CC / Polk MC80 / Polk PSW150 sub

    Bedroom - Sharp Aquos 70" 650 / Pioneer SC-1222k / Polk RT-55 / Polk CS-250

    Den - Rotel RSP-1068 / Threshold CAS-2 / Boston VR-M60 / BDP-05FD
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  • Polkersince85
    Polkersince85 Posts: 2,883
    edited August 2009
    Some of the earlier TFM-25s were bad about the transistor solder connections. Hope this helps.
    >
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    >This message has been scanned by the NSA and found to be free of harmful intent.<
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  • Tony M
    Tony M Posts: 11,545
    edited August 2009
    Your pretty good with circuits tuan, I think your going to fix that thing.
    Most people just listen to music and watch movies. I EXPERIENCE them.

    “Anger is an acid that can do more harm to the vessel in which it is stored than to anything on which it is poured.”
    --Mark Twain.
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  • nguyendot
    nguyendot Posts: 3,594
    edited August 2009
    Polkersince85 wrote: »
    Some of the earlier TFM-25s were bad about the transistor solder connections. Hope this helps.

    On the input stage PCB?

    If so I'll resolder them, there aren't many.
    Main Surround -
    Epson 8350 Projector/ Elite Screens 120" / Pioneer Elite SC-35 / Sunfire Signature / Focal Chorus 716s / Focal Chorus CC / Polk MC80 / Polk PSW150 sub

    Bedroom - Sharp Aquos 70" 650 / Pioneer SC-1222k / Polk RT-55 / Polk CS-250

    Den - Rotel RSP-1068 / Threshold CAS-2 / Boston VR-M60 / BDP-05FD
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  • cwsmith68
    cwsmith68 Posts: 434
    edited December 2011
    Anyone in the club good with fixing Carver amps? TFM LINE?
    Main system:
    Denon PRA-1500, Denon POA-2400, Denon TU-660, Denon DCD-2560, Denon DVD-2910, Denon DRS-640, Denon DP-30L II w/DL-301 mc cart, BSR EQ-3000, DCM Timeframe 600's
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  • gdb
    gdb Posts: 6,012
    edited December 2011
    There is only one place that I send Carver gear to: http://www.hitechaudioltd.com/ Talk to Rolland.:wink:
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  • cwsmith68
    cwsmith68 Posts: 434
    edited December 2011
    Cool. Thanks. I'll give em a call next week.
    Main system:
    Denon PRA-1500, Denon POA-2400, Denon TU-660, Denon DCD-2560, Denon DVD-2910, Denon DRS-640, Denon DP-30L II w/DL-301 mc cart, BSR EQ-3000, DCM Timeframe 600's
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