Are new tubes supposed to do this?

I have a pair of VTL Mono 120 that uses 4 807 tubes per side. Previously it had Chinese Shinto tube that came with it but I decided to change to a few of RCA and General electric tubes that I had on hand.

After changing and making sure I had the correct bias, I pressed play on my cdp but about 5 min. into the song, all of a sudden there was a very bright flash almost like a burst of lighting discharge came on in of of the tube accompanied by a very loud static noise from the speaker. I got scared then hurried to turn off the cdp BUT not the amp to make sure the music stop. The flash went away. When I remeasured the bias point of that specific tube again, it read almost 0V (260mv is the recommend bias point). I decided to try playing the cdp again to see if the same thing would happend again but this time, everything seemed fine -- no flash nor pop -- and the music didn't seem to suffer in term of quality.

But to make sure that the tube itself was not to blame for the bizarre thing, I then exchanged for another Ge tube. I then turn on the amp again but right at the moment when the amp was turned on, there goes that big flash again in that same tube position which prompted me to turn of the amp immediately. I told myself what the heck, held my breath and turn on the unit one more time. BUT this time there was nothing, just a small static sound but went away immediately after 1 or 2 second. I then replay the same song for about 10 minutes but everything sounded fine. I then turned off everything, waited another 15 min. to turn the amp on again, everything seems fine now but initially there is still a few soft tick and pop but then it all went away.

One thing I did which I thought might have caused it is that I change the tube when the amp was still warm. I don't know if you have to wait for the amp to cool down before changing the tube.

I am new to tube but I don't know if anyone had similar experience or know what was going on with what my amp? I will probably try to call VTL on Monday to see if they know anything.

By the way, RCA and GE tubes sound a lot more transparent, airy, more 3D, bigger soundstage than the Chinese tube. I just couldn't believe the differences.
I think you have a bad tube. It may get worse. You should call whoever sold it to you and try to get a new one.
No, they're not supposed to do that. It sounds like some voltage may be arcing across the tube pins at turn on. You might want to look at the underside of the circuit board to see if you can locate the place (burnt spot) where the arcing is taking place. If it were my amp, I'd take it to a tech for service rather than risk damaging the amp. I'd want to take care of this minor problem before it became a major problem down the road.
They shouldn't do that, and it is NOT a minor problem when an amp smokes output tubes in minutes. It went from normal bias to zero volt output, and flashed another tube in the same location. The only possibilities are: very poorly matched tubes, a bad batch of tubes (for example, you may have tubes that were rejected by someone else), incompatibility with GE tubes or an amp malfunction.

I recommend seeing if the amp performs properly with the original tubes; if so, the amp is not at fault, leaving only the tubes as culprits (if it doesn't bias properly, the flashes damaged the amp). I seem to remember that VTL likes to use higher than usual plate voltages, and maybe the GEs cannot handle it. If the RCAs work fine, maybe you should track down some more of them and dump those GEs.
Does your amp delay the B+ at turn on? Tubes, output tubes in particular, can arc if the high voltage is present before the cathode can build up a sufficient space charge of electrons. This can also occur with "weak" or old output tubes that are driven hard. There isn't enough space charge to supply the current needs and cathode stripping can occur; which can lead to arcing.
John: I am not sure if the amp delays the B+ at turn on.

On thing I forgot to mention is that I replace the tube when the amp is slightly warm. Maybe there was a mismatch in temprature between the tube at turn on but I am not sure.

On thing I notice is that the trouble tube does not have a blue glow on its glass surface like the others in the same amp.

I bought those tubes from Ebay so that may explain whay tubes are bad.

Does anyone know of a good place to buy some good RCA 807?
My other tube that was good now went up in flame too. Somehow the bad tube is now affecting others ... like a virus.
Yes. A shorted tube can cause all kinds of problem from blowing your output transformer, retifier tube, and other things in the chain.
i don't think the VTLs delay the B+. I've smoked a number of fuses due to power surges but the only problem i had with tubes was from a near lightning hit which took out the fueses and one tube. given the fact the tubes were going in the same location i'd vote for an amp problem and not use it until you fix it so you don't follow a potential minor problem with things like trannies.

sounds to me like something is shorting out. the impact of the amp being warm could be that when hot the trouble spot has expanded to cause the short and when cold it doesn't make contact. I had a guitar amp with a bad resistor connection that mad the amp cut out until it warmed finally went totally south. also replacing the tubes a couple of times could have moved the socket enought to maybe seperate the trouble spots. send it in!
I think it was a bad tube I put in. After putting back the tubes that known to be good, everything was fine.

Thanks for all input.