Mesa power tube color codes vs Ruby tube PC number

[Orville]

This is related to another thread I started and got great help with, but I thought it would be more appropriate to channel this question thru a new thread.

I have Ruby el84's in my TA-30 Mesa. They are JJ's. They replaced Mesa el84's that I am 99% sure are Sovtec's. 1 Mesa went bad so my tech threw in a quad of Ruby's on my OK since I couldn't find another pair of Greens.
Ruby JJ's box says they tested at PC:23 TC:5950. I was not able to find much online regarding how Ruby tests their tubes so I am not sure how hot they are. They seem maybe a bit hotter than the Mesa Green, but since I don't have a working quad of the Greens I had to leave the out 2 sockets with JJ's and just swap the inside pair with working Greens and keep the amp at 15 watts.
Anyone have experience with Ruby's PC values? I read all over the web that JJ's el84 is well regarded, but i like the Mesa Green's better. I don't know if that is a tube mfg thing or is it a hotter tube thing. I also find that when shopping for Mesa tubes nobody seems to know or care what color code they are. Maybe that is telling me something, but I'd like to know.
Thanks !!

[ItsaBass]

Re: Mesa power tube color codes vs Ruby tube PC number

I don't know about the color codes (other than that my Mesa EL-84's were black).

What I do know is that my Express Plus would short power tubes left and right. (There is a thread here about it somewhere.) At the time (2012 or so), the manager of the Mesa shop in Los Angeles told me that they were considering switching to JJ EL-84's, because they were supposedly a bit beefier that what Mesa used. He also said that the Express is rough on power tubes, and expressed his frustration that there really wasn't much choice out there any more, so they were pretty much forced to pick from a bunch of bad options to source their tubes. He suggested that once my warranty was up, I switch over to the new old stock military spec EL-84's (I forgot the number that they use for them, but it's not EL-84).

Any rate, the point is that a highly experienced and factory trained Mesa employee basically told me that their EL-84's aren't that great. So I wouldn't be scared about doing any upgrades.

Strangely enough, the amp hasn't shorted any tubes since my last visit there.

[Darg1911]

Re: Mesa power tube color codes vs Ruby tube PC number

You may want to contact Dougs Tubes. I'm sure he can offer good advice and set you up with whatever you want.
The Tube Store and Tube Depot both have retube kits specific for different amps but I think they only offer full re-tube sets. But you can contact them to check.

This was the old Mesa to Groove Tubes "conversion". Not worth much (IMO). Not sure if there is a Mesa to Ruby one.

Mesa - Groove Tubes scale
Red = 4
Yellow =4
Green =5
Gray =5
Blue =6
White =6

[InbredJunk]

Re: Mesa power tube color codes vs Ruby tube PC number

If you can find out what your bias is, and compare that to mesa spec. It would be a good indicator. The green code tubes are supposed to be the closest to the middle ground as far as bias goes. Not hot and not cold. I was told this information by an old amp tech that may or may not have lost his mind. He's quite a character and I'm not sure I believe him or not.

I had the same question about their 6l6 tubes.

Sent from my SAMSUNG-SM-G891A using Tapatalk

[dave74]

Re: Mesa power tube color codes vs Ruby tube PC number

If you can find out what your bias is, and compare that to mesa spec. It would be a good indicator. The green code tubes are supposed to be the closest to the middle ground as far as bias goes. Not hot and not cold. I was told this information by an old amp tech that may or may not have lost his mind. He's quite a character and I'm not sure I believe him or not.

I had the same question about their 6l6 tubes.

Sent from my SAMSUNG-SM-G891A using Tapatalk

Yeah he is right, the greens are indeed in the middle of the range. I was told they were in the middle but that the difference would be very hard to tell with high gain.
I've requested and received all greens both times ordering Mesa str440 sets. Not for tone reasons,,,,,I just like the color green! lol who doesn't?

[BlueFrankie]

Re: Mesa power tube color codes vs Ruby tube PC number

I use the eurotubes guys. They really know Mesa's and provide tubes that can handle the harsh el-84 cabinet/combo environment.