I bought a mud monster

[Hotrod]

I just bought a Mesa Boogie Trem-O-Verb head and I have a quick question for the tube guru's. It is used and about 1 year old and has the 6L6's in it. When the Stanby is off, they glo a nice orange, but as soon as I turn it to on, they get a blue glow them. It is all four power tubes and only the power tubes. What does this mean? I've never seen this before in any tube head, (that I know of). Anyhoo, I just got it yesterday and so far, I really like it. I can see now where someone may play one for a few minutes and walk away thinking it's just a muddy tone sucker [img]graemlins/laugh.gif[/img] . It's probably going to take a while to get it dimed in pretty good, but a lot of that is just all the combinations of settings this thing has. It appears to be very versital and I think I'm going to like it really well. I'm just concerned about the tube issue for now and I may even try EL34's later down the road just for some variety. Any input would be greatly appreciated.

And thanks to Troy and Matt of Ventt for taking the time to answer my onslaught of questions regarding the Recto series. It really helped a lot. Chuck also took a lot of time in answering questions for me and that was also greatly appreciated. (Just couldn't quite swing a SLO)

Thanks

[ March 18, 2003, 09:39 PM: Message edited by: Hotrod ]

[Cleveland Metal]

Re: I bought a mud monster

Some tubes emit a bluish-colored glow. There are TWO causes for this glow in audio power tubes. One is normal and harmless, the other occurs in a bad tube.

Power tubes will often show a very deep blue color. It can appear wherever the electrons from the cathode can strike a solid object. It is caused by impurities, such as cobalt, in the object and is harmless. It's normal and does not indicate a tube failure.

Occasionally a tube will develop a leak. The glow of ionized air is different from the fluorescence glow above. Ionized air is a purple color, almost pink. This color usually appears INSIDE the plate of the tube. It does not cling to surfaces, like fluorescence, but appears in the spaces BETWEEN elements. A tube showing this glow should be replaced as it can damage the amplifier.

[horns666]

Re: I bought a mud monster

John ...I love it when ya talk dirty [img]images/icons/rolleyes.gif[/img]

[Hotrod]

Re: I bought a mud monster

Thanks for the response Cleveland. So, these are kind of a rich, florescent, pastel blue and not really a purple. Do you think that might just be the natural properties of the tube? Seeing as to how they are all doing it, I don't necessarily think it is bad tubes, but I thought I remembered something about bias settings, if they are not right, your tubes might glow blue or bright yellow-white. I was just curious and I'll probably try to call Mesa tomorrow just to ask their tech support. I just wanted some opinions here, because I think there's better tube guys here than anywhere.

Thanks again

[OklaStrat]

Re: I bought a mud monster

If your bias is running too hot, the plates will glow cherry red. I wouldn't worry about the blue glow, personally. If you don't know how old the tubes are, get some new ones and put your old ones up as emergency spares. BTW, on the rectifiers I had generally the best tone was keeping the eq as close to 'noon' as possible. Any time I had eq knobs dimed or fully cut it really affected the tone in a bad way.

Pete

[Troy from VENTT]

Re: I bought a mud monster

Originally posted by Hotrod:
thanks to Troy and Matt of Ventt for taking the time to answer my onslaught of questions regarding the Recto series. It really helped a lot.
Thanks

<font size="2" face="Verdana, Helvetica, sans-serif">No problem! Glad to help. BTW, my 6L6's had a blue glow to them as well before I replaced them with my EL34's and those tubes were brand new so I wouldn't think there was a problem with the tubes.