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Seeking schematic for Rotel RB-890 power amplifier
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<blockquote data-quote="ludo" data-source="post: 94287" data-attributes="member: 691"><p>The MJLs should work fine, if they fit (larger package?) </p><p></p><p>The 2SD1047&2SB817s I had last all had a seriously sharp edge on the heat sink tab. It would pierce the mica washer in time. Had to be filed flat, then they actually worked OK :<img src="data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7" class="smilie smilie--sprite smilie--sprite1" alt=":)" title="Smile :)" loading="lazy" data-shortname=":)" /></p><p></p><p>Have sourced a lot of Toshiba 2SA/2SC big 'uns and small 'uns in the mean time. Let me know if you get stuck.</p><p></p><p>Things that work today and pop tomorrow for no apparent reason might also be oscillating. Have you had it on a 'scope?</p><p></p><p>It's partly superstition, and partly there is some reason to be superstitious, but I never keep bipolars that survived a blow-out. Replace the lot in a bank that has a dead one. Mosfets are more easy going about near-death experiences so one can trust the survivors, but not so with bipolars.</p><p></p><p></p><p></p><p></p><p>Thanks for the tip Joel. I just know it's going to come up one day. I've had that with a too long bolt to fasten the cover. The thing just kept coming back :-\</p></blockquote><p></p>
[QUOTE="ludo, post: 94287, member: 691"] The MJLs should work fine, if they fit (larger package?) The 2SD1047&2SB817s I had last all had a seriously sharp edge on the heat sink tab. It would pierce the mica washer in time. Had to be filed flat, then they actually worked OK ::) Have sourced a lot of Toshiba 2SA/2SC big 'uns and small 'uns in the mean time. Let me know if you get stuck. Things that work today and pop tomorrow for no apparent reason might also be oscillating. Have you had it on a 'scope? It's partly superstition, and partly there is some reason to be superstitious, but I never keep bipolars that survived a blow-out. Replace the lot in a bank that has a dead one. Mosfets are more easy going about near-death experiences so one can trust the survivors, but not so with bipolars. Thanks for the tip Joel. I just know it's going to come up one day. I've had that with a too long bolt to fasten the cover. The thing just kept coming back :-\ [/QUOTE]
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Seeking schematic for Rotel RB-890 power amplifier
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