If you enjoy a very linear, extended freq. response(without glare or bloat), liquid mids(no coloration) and wide dynamics: The pre-1968 Siemens CCa is the tube for you. The ones manufactured after '68(silver plate under getter support and internal date code) are rather strident on top. The early CCa's are very costly lately, because so many share this opinion, but worth every penny. The E188CC/7308 is no slouch either. In an otherwise transparent system, they will provide you with a very natural presentation. Whatever tubes you choose to seek out: Be certain they are tested and certified "pre-amp grade".
