the juicy music uses 6922 tubes ,the newer ones also had the 6h30 tube these for sure present a more neutral presentation the slp98 uses the 6sn7 which creates a much wider sound stage as well as air around the instruments ,
if youwould like to call this bloomy but not much ,not like a 300b also if you use a good solid NOS tube they all sound a little different please also remember the 09 uses the great 5ar4 rectifier tube and this controls the balance of the performance the stock one is ok ,get a Vintage Amperex or Mullard they last for years , The Amperex white or orange pq 6922 tube
would give you a nice slightly warm balance .