Crown K1 & K2 Refurbishment

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   Finally got round working on two of my Crown K series amps that have been gathering dust.  Legendary class I BCA design.  

First one K1, had a slight fault where one IOC light would illuminate dimly and the K2 would only start up occasionally.   

Both amps required a full recap on all boards. Original ones, the  ESR were getting higher when checking boards over.  K1 also had little solder on some joints of components so re flowed them.  Nichicon PW and VZ caps used.  Lots of 100uF caps on these boards and bi-polar 2.2uF's.  Higher voltage and higher temp than the original caps.   K1 was built in 1997 early model and K2 in 1999.  The K2 solder joints and PCB seemed higher quality, than the early K1. very easy to de-solder and solder.  Nice solder flow.

Put back together, output modules carefully put back onto heat pads and torqued down equally and then resistance checked between case and modules.  Overlap/underlap checked on scope at first start ups which was fine.  Load tested and met specs and abit over.  Forgot how good these amps sound.  Amazing clarity and tight bass from the high damping factor.  Much better starting up now too.  

Edited by shaun1264 - 18 April 2020 at 8:36pm

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shaun1264 Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 06 September 2013 Location: Surrey Status: Offline Points: 292	Post Options Post Reply Quote shaun1264 Report Post Thanks(0) Quote Reply Topic: Crown K1 & K2 Refurbishment Posted: 18 April 2020 at 8:28pm
	Finally got round working on two of my Crown K series amps that have been gathering dust. Legendary class I BCA design. First one K1, had a slight fault where one IOC light would illuminate dimly and the K2 would only start up occasionally. Both amps required a full recap on all boards. Original ones, the ESR were getting higher when checking boards over. K1 also had little solder on some joints of components so re flowed them. Nichicon PW and VZ caps used. Lots of 100uF caps on these boards and bi-polar 2.2uF's. Higher voltage and higher temp than the original caps. K1 was built in 1997 early model and K2 in 1999. The K2 solder joints and PCB seemed higher quality, than the early K1. very easy to de-solder and solder. Nice solder flow. Put back together, output modules carefully put back onto heat pads and torqued down equally and then resistance checked between case and modules. Overlap/underlap checked on scope at first start ups which was fine. Load tested and met specs and abit over. Forgot how good these amps sound. Amazing clarity and tight bass from the high damping factor. Much better starting up now too. Edited by shaun1264 - 18 April 2020 at 8:36pm

Earplug Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 03 January 2012 Location: Europe Status: Offline Points: 7216	Post Options Post Reply Quote Earplug Report Post Thanks(0) Quote Reply Posted: 19 April 2020 at 9:15am
	Nice. They are good amps - but lack of fans does cause problems - like the caps drying out, etc.
	Earplugs Are For Wimps!

shaun1264 Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 06 September 2013 Location: Surrey Status: Offline Points: 292	Post Options Post Reply Quote shaun1264 Report Post Thanks(0) Quote Reply Posted: 27 April 2020 at 9:25pm
	Thanks :) amps are working well so I'm quite confident on my work