Namely the Carvin TS100. To switch from EL34 to 6L6GC safely and back is it really as easy as a flip of the switch? or is adjusting the bias pot required as well
im pretty sure 6l6s have a lower output than el34s. I think 34s are 18w i might be wrong though.
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What im asking is if I can just pop in 6L6, flip the switch...and just play without having to further bias with the pot the old school way... (im sure it wont be optimal..im just asking is it possible)
pin setup is different, you'd have to switch some of the wiring around but its not too difficult if you are familiar with the pin setup of the tubes, and rebias as well. el34s and 6l6s draw different currents and have different operating points.

If you have an old school trim pot bias, you should be rebiasing every time you replace tubes.

edit: or is there a particular feature that I'm missing here?
Last edited by al112987 at Aug 15, 2008,
Inside the amp there is a bias select switch for tube type. There is also a bias potentiometer as well as a bias pot. Now what I am thinking is that the switch is there so that you can put in w/e EL34 or 6L6 to run it SAFELY...not exactly optimally (im guessing colder than what is optimal in order for it to be universal...) and im guessing that the bias pots are there to fine tune and get the desired amoung of mA's to the tubes. basically what i want to know is if i can put in 6L6 and run them without biasing them to the optimal 50mA (yet)
Then probably. If your amp has two independent bias channels, you probably don't need to rewire anything. I mean... you COULD run the tubes safetly but if they're biased too hot you will fry your tubes. Its best to just bias when you install them. I guess you could try it, play it and watch for redplating for now.
i also want to do this. i would like to have a switch installed (just for the pinout, itd be a little convoluted to actually have seperate bias paths i would assume).
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I called up thetubestore. they said i cant do it cuz most 5881s now are just 6L6GC that are relabeled, however tungsols are true 5881's. but i called carvin and talked to a tech and an engineer. they said that the bias is not set to maximum plate voltage for a 5881 (400mv) let alone a 6L6GC (500mv) so either will work with the switch. then you can go in with the adjustable bias and bias it as necessary to suit whichever tube you have in