[slinco]

Hello Roger -
I'm going to be making a tube purchase and have been looking over your TubeAudioStore website. After reading the information there I'm a bit confused. You mention that tubes are graded "A", "SA", "BB, and "CC", but when I look at the tubes listed for sale I only see one version for sale, with no grade shown (except for the low noise, super low noise choices on some of the preamp tubes). Am I missing something?

 Also, on the power tubes page, only one tube is branded "RAM" (a KT88). Does this mean the other non RAM tubes aren't tested as thoroughly, or are a lower grade?

Thanks for your help.

Steve

[Roger A. Modjeski]

Steve,

Sorry for the confusion over the grading system. A while back we changed from double letter grades that represented the values in each section. We have simplified the system so that a SLN tube has 2 super low noise sections. A LN has 2 low noise (A) sections. We still put the individual letter grades on the box for those who know which section of the tube needs to be quiet.

In a preamp some designers use both sections of the same tube as first amplifier left and right. Another designer might use section 1 as input and section 2 as second sage. This is what I did in the RM-1. This allows the use of tubes that have on quiet section and one not so quiet section such as an AB, AC or AD tube. Since the gain of the first outweighs the noise contribution of the second stage, the second stage will not add to the noise.

All our tubes are tested to the same standards and branded RAM though some photos may not show it.