Onix SP3

Can somebody please tell me why when I turn my amp on the rear tubes (small ones) on either side go really bright for a millisecond and then dimmer down? It plays and sounds fine, the bias is set correctly. It has been doing this since I bought it. It has had minimum use, maybe 50 hours (if that).
Anyone got any ideas please?
some tubes like Mullards do that all the time..My guess is your not having any problems to worry about..
When I owned tube equipment, I had a preamp with 12AU7 tubes. Certain brands would flash brightly when powered on. I checked with two tube vendors who assured me that the flash was nothing to worry about -- that it was a characteristic of some brands and not others. So perhaps the same is true for the tubes in your Onix.
Yep, it's normal for many small tubes from Eastern Europe. My EI's love to flash. Interestingly Russians just aren't 'flashy' at all. I guess I prefer flashy tubes, just so long as they are not power tubes. :-)
Thank you guys for clarifying that for me!.