ARC SD135 will not turn on -- fearing the worst
Yesterday my Audio Research SD135 power amp failed. I turned it on, and the amber protect light quickly turned to green---and then winked out. Then, nothing. Replacing the fuse changes nothing. I have an old ARC D130 that I was able to swap in; it and the rest of my system are working fine.
I sent an email to Audio Research service. Actually, I replied to a previous note from them about the service they were performing on this same amplifier. A few years ago, they replaced a bunch of parts and sent it back, and the amp has seen only light use since then. In his note, Kalvin mentioned problems with the ThermalTrak transistors. I noticed a recent thread that claims these parts are no longer being made. And Kalvin has retired. I hope ARC can do something for me. Any suggestions?
By the way, my power amp is fed by an ARC LS 27, and the speakers are Vandersteen Treo.
I sent an email to Audio Research service. Actually, I replied to a previous note from them about the service they were performing on this same amplifier. A few years ago, they replaced a bunch of parts and sent it back, and the amp has seen only light use since then. In his note, Kalvin mentioned problems with the ThermalTrak transistors. I noticed a recent thread that claims these parts are no longer being made. And Kalvin has retired. I hope ARC can do something for me. Any suggestions?
By the way, my power amp is fed by an ARC LS 27, and the speakers are Vandersteen Treo.
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- 9 posts total
A follow-up from ARC, with some suggestions:
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Here's a thread from two years ago, about another broken SD135. In this poster's case, ARC gave him a credit toward a new amp. The thread discusses the ThermalTrak transistors, which had been discontinued. There's a new version of those parts, but it's not compatible with ARC's design. Apparently, ARC never found a workaround using the new versions of the parts. https://forum.audiogon.com/discussions/my-amp-is-broken-not-sure-what-to-do-any-recommendations/post?highlight=sd135&postid=1637744#1637744 ARC service suggested that used ARC models D240, DS225, DS450 might be of interest. Perhaps a used Ayre power amp might also be a candidate. My preamp is an ARC LS 27, and the speakers are Vandersteen Treo. Thanks! |
I would like to hear from anyone who has replaced the ThermalTrak transistors recently. My tech tells me that replacement parts are entirely compatible with the original amp design: The type # changed slightly, from NJL3281D & NJL1302D to NJL3281DG & NJL1302DG, to signify lead free. This simply means the solder used to "pre-tin" the device pins is no longer lead/tin blend. There was NO other change to device. But I heard a second-hand account from a Mcintosh tech that they had several amps fail because there was indeed a difference between the leaded and non-leaded devices. So is there more to this story than just the part numbers? It would help to have validation from someone who had repaired an SD135 recently. Thanks... |
Regarding ARC's product suggestions to me, has anyone compared the SD135 with its class-D successor, the DS225? I'm not sure about the class-D. But the DS225 has a lot more power supply energy storage going for it, and no overall negative feedback, according to https://www.arcdb.ws/model/DS225 I'm also interested in Nakamichi Stasis amps, although I haven't seen any comments about their use with Vandersteen speakers. |
- 9 posts total