[beat]

Hey guys,
I am setting up a PP kt88 amp for my friend. The chinese tubes that came with the unit are two matched pair instead of a matched quad. I know it will have to be biased after I get them in there but what would you guys do.. 1. have the matched ones on only one channel or 2. mix them so each channel gets one of each? Two measure 38 and other two are at 56 so the difference is relatively substantial.

thanks, Beat

[JohnR]

Put a matched pair in each channel. Since it's a push-pull amp you want the two tubes for each channel to be closer in characteristic -- the bias adjustment will then bring both tubes into the right operating range.

(Unless the amp has individual bias adjustments per tube, which is fairly uncommon I think. Even so, I would do the same thing.)