Tube rolling Audio Note DACs

I have an Audio Note 2.1x balanced DAC. One of the output tubes recently went bad (they were stock Philips) so i replaced them all with NOS in a bit of tube rolling fun. However, I could swear the new output tubes -- 7308/E188CC Siemens 1969 branded Westinghouse -- have a recessed midrange, but I can't be sure about this as these tubes also have better bass and high-end output than the stock tubes. They may just be better balanced.

Any other output tubes to try on the AN DAC?

Thanks.