2. amps-preamps
  3. 152366-13953

Kondo Ongaku needing advise

Need advise from members. 

This is my Kondo ongaku amp. I bought it brand new from a US dealer in 2008. I started notice some discolouration 2-3 years ago on the copper chassis. It is getting worse. It likes kind of rusting but it is NOT on the surface. It is growing from the inside of the chassis. If you feel the surface of the chassis by hand you cannot feel it and the surface is smooth. The local dealer inspected the amp and found nothing wrong except the chassis. All other plates are in mint condition as I really take good care of it. I emailed Kondo Japan company and they asked me to ship it back to the company for repair/ replacement. I live in Asia and, even do, the company quoted me USD 6500 for replace of that chassis. Anyone has a better idea of what it is and how to treat? It’s a bit too expensive to replace one chassis at the cost of USD 6500.


nicksun
gsm18439
895 posts
 
Can you upload some photos?
roberjerman
4,319 posts
 
Typical copper corrosion! Regular polishing with Copper Brite will keep it at bay!  The only permanent fix is application of a clear sealent (laquer or polyurethane) over the copper. Be thankful it is only on the inside! It will NOT affect the sound quality! 
roberjerman
4,319 posts
 
Silver does the same thing - it turns black! Copper turns green/blue when exposed to air (oxidation - rust). A clear sealant applied before this happens is the solution. I thought that the Ongaku's outer surfaces had this already done? Apparently the inside was neglected! Rather unacceptable in a $40K+ amp!
testpilot
897 posts
 
Did you ask Kondo if the copper top plate is raw copper or copper with a clear coating?  If the former, you can expect copper to oxidize.  If clear coated (which protects copper from oxidizing), I would ask Kondo why the top plate is now oxidizing?  Perhaps a manufacturing defect?
More to discover