Monday, November 30, 2009

Power tube saga.Treasures 6ca7-z,Gold lion reissue KT88,Ei KT90,GE 6550A

Power Tube.

Last week was a very interested week where 4 type of power tube been tested on Marantz 8b.To make this possible the bias is been modify to accomodate the 6550 and kt88 tube. The sequence tested is as follow;

TREASURE 6CA7-7, Shuguang celebrate make this to celebrate 50th anniversary.

Treasures 6ca7-z

Gold lion reissue KT88

Ei KT90

GE 6550A.

At that night I rank them as follow

1ST GE6550A

2ND Ei kt90

3rd treasures 6ca7-z and reissue kt88.(Both have their own sound characteristic that may appeal to different user)

As time is not permitted we have not tested the Sylvania and telefunken metal base EL34 that in the owner collection.

I still say NOS tube still rule.Even  Marantz 8b that been optimise for EL34 i still prefer  the NOS GE 6550A 

*More picture will be add later.



  1. Thought that EL34 tubes shoot out should be carried out on M8. Interesting result. I wonder how GEC KT88 perform vs the GE6550.

  2. Hi Lee,

    too bad we don't have any GEC kt88 here.