|
Conrad-Johnson It just sounds right |
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
LP125sa - plate fuse blown.. now what?
Hi All,
I recently replaced the output tubes in my LP125sa, and after about three days of successful running, I have found that I have no output on the left channel, and the plate fuse indicator is illuminated. The instructions on how to replace the fuse are somewhat opaque in the manual, although all becomes clear when you remove the base cover. Sure enough, the left channel plate fuse is open circuit. Is it ok just to replace it and hope for the best?. I am presuming that there must have been some fault on one of the replacement tubes to cause it to blow. Am I running the risk of a problem by replacing it to test the tubes? Regards, Alex
__________________
Technics SL1210| Jelco SA-750| Benz Micro ACE SM MC| Squeezebox Touch/MCRU linear PSU | Cambridge Audio 851C | High Resolution Music Streamer II+ / Linestreamer + | Conrad-Johnson PV-15 Control Amplifier| Conrad-Johnson LP125sa| Avalon NP Evo 2.0 Speakers| Cardas Audio Quadlink-5C Speaker Cables and Interconnects| Finite Elemente Pagode Signature E-14 equipment support |
#2
|
||||
|
||||
If it was me, I would remove the new tubes from the channel that blew and replace them with the old tubes to begin with. If the fuze blows again I would disconnect all IC/speaker wires and try again
__________________
2 Channel - Esoteric KO3, VPI Classic, C2300, MS300, MEN220, Bryston 7b SST, B&W 802D, JL F113 (2), MDA 1000, Olive 4HD, Sonos w/Remedy, WW Silver Eclipse ICs , Stillpoints Ultra mini, MR85 tuner, Aurender A10 server Headphone listening - Audeze LCD3 with Moon Audio Black Dragon Balanced cables, Sennheiser HD650, WW silver Eclipse Nano cable, Bryston BHA-1 amp HT - MX135, OPPO 103D, B&W CDM7, B&W center, Sony 65" LCD |
#3
|
|||
|
|||
Thanks - that sounds like a sensible plan.
I hve had a look at the circuit board, and it looks like there is a lot of flux around the base of the of the sockets, and what looks like some possible scortching on the board. I'm going to examine it more closely tomorrow, and if I don't like the look of it it will be going back to the dealer for inspection and a check-over before I run it again. I do hope there isn't an issue as I would be unlikely to get it back this side of Christmas Regards, Alex
__________________
Technics SL1210| Jelco SA-750| Benz Micro ACE SM MC| Squeezebox Touch/MCRU linear PSU | Cambridge Audio 851C | High Resolution Music Streamer II+ / Linestreamer + | Conrad-Johnson PV-15 Control Amplifier| Conrad-Johnson LP125sa| Avalon NP Evo 2.0 Speakers| Cardas Audio Quadlink-5C Speaker Cables and Interconnects| Finite Elemente Pagode Signature E-14 equipment support |
#4
|
||||
|
||||
Quote:
__________________
Avid Acutus SP, NO ARM, Benz Micro LP-S, Whest Audio PS.40RDT SE, PS Audio DSMP+DS DAC, Simaudio Moon 700i, Dali Epicon 6, Simaudio Moon Nēo 430HAD, HiFiMan HE-1000v2, Chord Sarum SA XLR, RCA, USB, Chord Sarum speaker, Nordost Vishnu power, Furutech plugs, PS Audio P10+Chord Sarum SA power, Stillpoints Ultra SS, Ultra Mini and LPI, HiFi Racks rack, Audio Desk Systeme PRO+Keith Monks Omni RCM |
#5
|
|||
|
|||
Remember that generally tube power amplifiers require that the speakers are already connected on power up. It may not be a good idea to disconnect everything.
|
#6
|
|||
|
|||
OK, so I've had a closer look, and it isn't good news. there is a blown track around the base of v10, so the amp is a non-runner. I am engaging with the distributor about a return for repair, but it isn't going to be pretty - will need a hard-wired repair to the board, which I'm conceptually unhappy with.
__________________
Technics SL1210| Jelco SA-750| Benz Micro ACE SM MC| Squeezebox Touch/MCRU linear PSU | Cambridge Audio 851C | High Resolution Music Streamer II+ / Linestreamer + | Conrad-Johnson PV-15 Control Amplifier| Conrad-Johnson LP125sa| Avalon NP Evo 2.0 Speakers| Cardas Audio Quadlink-5C Speaker Cables and Interconnects| Finite Elemente Pagode Signature E-14 equipment support |
#7
|
||||
|
||||
Bummer. Sorry to hear about your amp woes. I just replaced the KT120 s in my LP70s. Maybe i should keep my fingers crossed. Its been very settled now for a while ( touch wood). Glad i didn't upset the apple cart, so to speak. I have only one suggestion for you. Mono Beatles. Have a very 60 s retro Christmas.
PS oh, sorry, you have the stereo version, not the monos. I was think SE not SA. Bummer. Last edited by Briz Vegaas; 12-14-2014 at 06:06 AM. |
#8
|
|||
|
|||
Hi Briz,
That's ok - I still had one working channel so the Beatles in glorious mono was still an option . Actually, thanks to the highly responsive distributor the amp has been repaired already and will be back with me imminently. Cause was an undisclosed manufacturing issue and was repaired FOC - can't say fairer than that, I suppose. Cheers, Alex
__________________
Technics SL1210| Jelco SA-750| Benz Micro ACE SM MC| Squeezebox Touch/MCRU linear PSU | Cambridge Audio 851C | High Resolution Music Streamer II+ / Linestreamer + | Conrad-Johnson PV-15 Control Amplifier| Conrad-Johnson LP125sa| Avalon NP Evo 2.0 Speakers| Cardas Audio Quadlink-5C Speaker Cables and Interconnects| Finite Elemente Pagode Signature E-14 equipment support Last edited by AlexM; 12-15-2014 at 06:32 PM. |
#9
|
|||
|
|||
Amp is back from repair and installed in the system, and sounding very nice indeed.
The damaged track has been repaired, presumably with a patch wire. It wasn't a tube related problem, but an issue with the solder mask being damaged that allowed a flash over, which is what caused the track to burn before the plate fuse blew. Not very happy with that, but it was fixed under warranty so no complaints about the service support.
__________________
Technics SL1210| Jelco SA-750| Benz Micro ACE SM MC| Squeezebox Touch/MCRU linear PSU | Cambridge Audio 851C | High Resolution Music Streamer II+ / Linestreamer + | Conrad-Johnson PV-15 Control Amplifier| Conrad-Johnson LP125sa| Avalon NP Evo 2.0 Speakers| Cardas Audio Quadlink-5C Speaker Cables and Interconnects| Finite Elemente Pagode Signature E-14 equipment support |
|
|
Audio Aficionado Sponsors | |