Only changing 2 power amp tubes in Mark IV?

[Herbie the Rad Dorklift]

I think my Mark Ivs about ready for some new power tubes, but I can;'t afford to get 4...

Can I buy 2 for the outside tubes just for now, then buy 2 more later on? Or do I have to buy a 4 set?

Cheers.

 

[kmanick]

inner and outer run in pairs.
get one pair and put them in the outer slots and run in class A
until you get a set for the inner pair.

I think my Mark Ivs about ready for some new power tubes, but I can;'t afford to get 4...

Can I buy 2 for the outside tubes just for now, then buy 2 more later on? Or do I have to buy a 4 set?

Cheers.

 

[stokes]

It is always best to do all 4 so you know you have them matched to run as efficiently as possible,but as long as you are using Mesa or some tube that is rated for your amp you will be safe.It may or may not sound its best,but it will be safe,even run in full power,no need to run only class A.Just change in pairs as described.As tubes burn in and wear some the bias point will drift a bit,so be aware that when you decide to change the other pair,buying a pair that matches the first pair wont be a "perfect" match anymore,depending on how long you wait to get the second pair changed.