Friend has AN-K’s he runs the AudioNote Cobra integrated and I have to say its a match made in heaven. Hugely enjoyable and some of the best sound I’ve heard in a while. Even the DAC is quite good in the cobra.
Not sure if it has sub out but IMO your better off using the hi level inputs to your sub then the low level ones. for example my REL recommended the hi level connection over the RCA/Balanced connection.
Another tube company I really like is Triode labs-Finale Audio out of Toronto. some of the best SET/PSET amps I’ve heard.
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