Looking for warm tube preamp (should pair well with Pass power amp), budget $6000

If you want to get a warmer sound from your SLP-05 try some NOS tubes. I love the old Sylvania tubes in it. Fuller and smoother then the stock tubes and just all around better sound. If you want a much warmer sound try NOS RCA tubes. I prefer the detail of Sylvania’s but everyone has a different taste and depends on the rest of your equipment. Try Brent at audiotubes.com.

there are NO NOS tubes you can sub for a 6H30 except a 6N6P - most would go into meltdown at the operating points they run at: they are mini power tubes. None would have anything like as low an output impedance. Their characteristics are very difficult to even come close to.

For the Cary SLP-05, it uses 6 6SN7’s.

mea culpa - should have read more carefully I assumed ARC

try swapping a couple of the 6H30 tubes with 6N6P‘s, preferably 60‘s Reflectors with the square getter if you can get hem. Should achieve what u want without changing gear :)

the SP14 is just a straightforward Aikido design, as published by John Broskie (see Tubecad Journal for full details) with regulated power supplies. Broskie also supplies pc boards and kits for versions which can use the 6SN7 and just about any other tube under the sun, should you so wish. Just google Aikido linestage, there‘s plenty written on the topology.