Looking for a softer tube


Currently using Philips SQ E88C tubes in my preamp (Lector Zoe ) and am looking for another tube that can give me the same detail, but a little warmer / softer on the top.

The Zoe can use a variety of different tubes :

12AT7/12AU7/6CG7/12BH7

So open for suggestions.
bjamz
Check with Andy at Vintage Tube Service's. His check process is impeccable. Tell him that you want "phono stage" tubes which are the least noisy.
NOS RCA 12au 7 Black top or clear top will work, and they are not as expensive as Mullards. I also believe their softer. In no way am I knocking Mullards, just differentiating.