Which power tube?Shuguang EL34B,Electro Harmonix EL34,Reissue MULLARD EL34,Reissue Gold Lion KT88,Treasures 6ca7-z,Ei KT90 ,Groove Tube EL34m , 6CA7

Shuguang EL34B

Electro Harmonix EL34
Reissue MULLARD EL34
Reissue Gold Lion KT88

Treasures 6ca7-z

Ei KT90 (Not in production)
Groove Tube EL34m , 6CA7(no longer listed on groove tube webpage).


First i have to say i have tested or listen to the above tube either in my own system, friends or in dealer system and not the result is not conclusive.
I would categories them under 2 batch distinctively by the origin of the tube.
I found even with the claim of different design I still find the sound characteristic is almost the same.
The first batch will be from China Shuguang that are more tonally pleasant but with bloated bass and sound “dirty” at the high.
This category of power tube is more suitable for small speaker or speaker with tight bass.In my system base on ls3/5a, i tends to favour this group.
This including the:
Treasures > GT 6CA7 = > GT EL34m(1ST BATCH)  => SHUGUANG EL34B

The second category will be from Russia.The sound is thin withn tight bass.Full range or big speaker tends to favour this group of power ube.
I also put the EI kt90 under this category as the sound is much closer to this category:

Ei   >    Gold Lion   =>   mullard   >     EH


>      BETTER
=>    EQUAVALENT OR BETTER.

I found that more better i rank  is usually improve on the dynamic and sound less "dirty".
This might lead to improve imagimg , soundstage and etc.Tonality is usually the same even with the claim of different design.


KLau

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.


KLau.