Newbee 6L6 question - I've blown one!

[Piers]

Hi,

Probably a numpty question but haven't found the answer here or through the power of google!

I have a Roadking II - my first tube amp and I've just had a severe short on one of the 6L6 valves (aged 6 months and 2 weeks so out of warranty - aggghhh!). I followed the diagnosis and rectification in the manual but it's definitely buggered so I need to replace it. When I looked online for replacement Mesa valves the only ones I can see have 10 AC GRY marked at the bottom of the valve but all the valves in my amp are marked 10 AC GRN.

I was more confused having checked the Mesa Boogie online store and seen their valves which they describe as being "The MESA 6L6 STR-440 is our very best overall 6L6 - It is a premium grade, US equivalent and our tube of choice in the production of all new Mesa 6L6 powered models" yet their picture also shows 10 AC GRY.

Very confused - pse help!

What does the GRN & GRY refer to?
Are they different?
If so is it ok to mix and match?

Thanks.

 

[trem]

Hi there..

The GRN (green) and GRY (grey) are color codes. They refer to the bias range of the tube. Some draw more current than the rest. Change all of them at the same time. According to Mesa, it doesn't matter which color code the tubes are as long as they're all Mesa labeled tube and as long as they're of the same color, because all Mesa tubes are within a narrow bias range anyway. Simul-class equipped amps though (your Road King not included), can have slightly hotter tubes on the outer slots.

So to summarize, don't mix and match, replace all of them. Go ahead and order, don't worry about the color.

 

[Piers]

Thanks for the reply, they're on order.

Just one more question. Roadking has 4 x 6L6's. How are they paired? The manual seems to suggest that as you look at them ordered 1-2-3-4, that 1-2 is a pair and 3-4 is a pair but it never states that is the case and when I spoke to the UK distributors they told me it was 1-4 and 2-3 (outer and inner).

Any ideas?

 

[trem]

Stick to the manual.

 

[Piers]

Just in case anyone else comes to this thread I checked with Mesa US: the Manual is wrong the tubes are arranged as inner and outer pairs so it is 1-4 and 2-3.

Every day's a school day as they say!

 

[trem]

Thanks.