mark IIC+ question about tranny edit: tube question

[kirk19]

Hi

How do you know if you have a 105 tranny. My serial number is 13778. What are the uprgrades on these to the original design? Thanks for the info

 

[Elpelotero]

look at the outside of the power transformer. it will have the number 105 embedded within its code.

 

[kirk19]

Hi

Thanks for the info it appears that I dont have a 105 tranny. I would like to know if its possible to change the 6l6 power tubes with mesa str430 tubes without having a problem with the bias. I know mesa is fixed bias but this is an early one and I dont know if the bias of this unit comes in the range of the bias nowadays used in boogies. Can I just swap the tubes out for new mesa 6l6 tubes?

 

[kirk19]

also I want to know witch tubes best to use in poweramp and preamp of the IIC+ since I think they might need replacement pretty soon. Thanks in advance

 

[Mahoner]

also I want to know witch tubes best to use in poweramp and preamp of the IIC+ since I think they might need replacement pretty soon.

What makes you think that the tubes need to be changed?

If you don't gig a lot the tubes will generally last a long time.

Pre amp tubes tend to go a lot quicker than power amp tubes. If you tap a pre amp tube with a pencil, and you get a "feedback" type of sound, it should be replaced. Don't worry about "matching sets".

A drastic loss of tone or volume is usually a power amp tube issue.

I recently had a C modded to a C+ and had Mesa install STR 440's for power tubes per Mike B's recomendation. THe amp sounds just as good as my other C+ with RCA Black Plates.