Which ECC83 or 12AX7 sounds very clean, neutral and honest?

This is probably the top class among ECC83 tubes, because they are intended above all to work cleanly and precisely:

ECC83 Premium S4A – sounds very clean and spatially structured, rich in detail, but not analytical – BTB tip

ECC803S Tung-Sol GOLD – sounds precise, clear, slightly tighter in the bass, and never becomes annoying

ECC803S JJ – clean, clear, honest, but slightly rounder in the highs

Unfortunately, the cleanest NOS tubes now cost a lot of money and have become rare, as there is naturally high demand here. To avoid unpleasant surprises, these should be purchased from a specialist dealer such as BTB Elektronik:

ECC803S Telefunken – the finest of the ECC83 tubes – the best, without ifs or buts

E83CC Siemens – without any doubt outstanding – everything is there, it does not become annoying, sounds like a tube – our NOS tip