Can you use KT120's in cj power amps

[turntable]

I know you can use KT88's, however can you use the KT120's?

Or would you even want to?

Has anyone tried yet?

[joeinid]

My only concern would be the bias lights and set points are for certain tubes and mA settings. Does C-J have to recalibrate the lights for certain tubes? If not, the tube bias I assume, would be incorrect.

Joe

[Rafale]

Originally Posted by turntable

I know you can use KT88's, however can you use the KT120's?

Or would you even want to?

Has anyone tried yet?

It would be necessary to ask the question to Ed

[ronenash]

Depends on the model. The new LP66s and LP125m should be fine since the SE versions of amps use KT120 tubes. I have heard of people using them successfully in the Premier 8 and Premier 12 as well as the MV60SE.
The bias is not the issue with this tube since you will typically use them at the same bias point as the 6550c. The problem with the KT120 is the fact that they use more current for the tube fillaments (1.8A vs. 1.6A in the KT88/6550). CJ have built enough headroom into their power transformers and this should not be a problem. I would be carefull with earlier amps (MV50, MV75, etc.). I am not sure their transformers are up to the task.

[Coppy]

My guess is that if C-J is switching to KT120s in some units, it's about the lack of availability of quality 6550s in sufficient numbers a manufacturer would require. It probably has nothing at all to do with sound quality.

[Rafale]

Originally Posted by Coppy

My guess is that if C-J is switching to KT120s in some units, it's about the lack of availability of quality 6550s in sufficient numbers a manufacturer would require. It probably has nothing at all to do with sound quality.

If it is true it is disturbing for the users of 6550....

[turntable]

Originally Posted by Coppy

My guess is that if C-J is switching to KT120s in some units, it's about the lack of availability of quality 6550s in sufficient numbers a manufacturer would require. It probably has nothing at all to do with sound quality.

That may well be true. the best sounding 6550 the " Svet whinged C " is not made anymore.

[Rafale]

Originally Posted by turntable

That may well be true. the best sounding 6550 the " Svet whinged C " is not made anymore.

Do we know why? What is at present the best choice 6550?

[turntable]

Looks like this may be the main cause - a legal battle

SED NEWS

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August 2011 - Distribution of SED Tubes into United States of America

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IN JUNE 2011 PM of AMERICA CEASED TO OFFER A DISTRIBUTION SERVICE FOR SED TUBES INTO UNITED STATES OF AMERICA. PM of America is no relation to PM Components LTD which is a UK based tube distribution company that has represented the St Petersburg factory in all areas of the world except USA for many years.

PM COMPONENTS LTD HAS BEEN ASKED TO OFFER A DISTRIBUTION SERVICE INTO USA AND HAS ACCEPTED THIS INVITATION. PM Components LTD is investigating the logistics of shipping direct to USA customers from St Petersburg to achieve best possible pricing but is meantime able to offer shipments at the prices shown below and on the terms stated from the UK.

[Rafale]

SED 6550 C winged still available in EU, see the link
Watford Valves :: Product - 6550C/SVETLANA/WINGED C