Re-bias for different brand of 6550's?

[Kurtai]

Hey all,

My penta labs 6550's blew out in my vintage JCM800 and I just ordered in some Groove Tube 6550c's. Should I be able to plug and play, or do I need to get it biased since it's a slightly different 6550 tube? Thanks!

 

[Lake Placid Blues]

Re: Re-bias for different brand of 6550's?

You must re-bias, or at least check the bias, every time, even when using the same type of tube with most Marshalls. The new mini Jubilees and the Astoria amps are cathode biased but a JCM800 will require the bias be checked and probably adjusted.

 

[Kurtai]

Re: Re-bias for different brand of 6550's?

You must re-bias, or at least check the bias, every time, even when using the same type of tube with most Marshalls. The new mini Jubilees and the Astoria amps are cathode biased but a JCM800 will require the bias be checked and probably adjusted.

Much appreciated!

 

[The JEM Ghost]

Re: Re-bias for different brand of 6550's?

You must re-bias, or at least check the bias, every time

Completely agree, check bias every time you change power tubes, even if it would be the same brand and type! ;-)