Pre-Amp Tubes

[ngibson]

hey quick question do they pre amp tubes light up the same way as the kt 66.in the kt 66's theres an orange glow in the middle of the tubes but with the pre amp theres no glow only what i think looks like a ring of glowing dots inside the tube.which also could be a glare from the power valves
Nathan.

[Dave W]

Go on the computer and do a search for Eurotubes. Read everything you can on that site. It will be a good one stop for basic tube knowledge. It worked for me. To answer your question. No the preamp tubes will not glow like the big power amp tubes, not anywhere as bright. The small preamp tubes are a completely separate design compared to the power tubes. That goes for any amp. There are many placed on the web for basic to detailed tube info, I just recommend that one because they are quality people. Good Luck!

[ngibson]

thanks alot man ill check that out.

[ngibson]

still i can barely notice any light coming from them.would you say there gone

[Dave W]

I am not an expert, but I know preamp tubes are to last way longer than poer tubes. They do not have much light or orange color when you look at them because there is not as much juice going thru them. The power amp and tubes section has tons more juice runnning through so they are bigger and brighter. The power tubes need more juice to amplify the sound of the pramp section. That is a basic description. If your amp works then your tubes work. Now if you see the power tubes one bright and one not then thats a whole different thing. If your preamp tubes have any visable light in them you should be alright, again is the amp working, then your alright.

[Slashwannabe1]

My pre amps on every tube amp I've ever owned has had a noticable glow to them kind of a medium orange not as bright as the power tubes but still bright enough. If its dark where you can barely see I'd say it should be changed,but only first after a tap on the tubes with a plastic pen... very lightly while the amp is on tap on the suspected problem tubes and if you can hear the tapping through the speaker without tapping very hard then that tube is on its way out and I'd recomend changing asap. Some people look down at this method but it has always helped eliminate a bad apple for me, and after replacing the microphonic tube my tone was always much better.

Good thing to keep in mind is to take note of the problem tubes color relative to the other pre amps, if they are all uniform in color perform the tube tap test mentioned above. Generally if you are concerned about your amps tone and if it has changed it probably is a bad tube in the mix, but if there are no problems in tone or volume I wouldn't worry about the lack of glow.