Thinking About Tube Rolling Again

[Byron4]

I have been using a pair of Quicksilver Mini Mono's for the past 5 years and I really like the sound of these amplifiers. Mike Sanders designed these amps for the el34 tube so he recommends using the el34's, kt77's, and 6l6's. I am still curious how the bigger tubes such as the 6550's, kt88's, and the kt90's would sound in these amps or any other amps in comparison when driving floor standing speakers even though it would not increase the power output. I am currently using Alon 1 speakers and seem to have enough power for reasonable listening levels using the smaller tubes. If anyone has done any comparisons recently your opinions would be appreciated.

[Almeida100]

I have a JOLIDA JD202A from late 1990’s and have roll the Chinese valves with JAN PHILLIPS 12AT7 (inverters), SOVTEK 12AX7LPS (drivers) and four 1999 SED Svetlana’s (“S” logo).
With this tube set, the amp sounded better, but dynamics and middle/treble extension was a bit shy, and dynamically, this set made the amp still a bit slow.
Than I read somewhere a review about ERSE MPX series capacitors, and decided to change the original block capacitors for these ones.
The “new” amp was completely different, having a stunning dynamics, pin-point imagery, with mids/treble on the bright side. Sometimes, depending on the record being played, that dynamics and bright treble seemed to my tastes somewhat aggressive. Bass was not too extended, but utterly tight, tuneful, making it very easy to follow bass lines.
That said, I went for a change on the driver stage, and tried a 5751 tube, this time from JJ TESLA, to calm down the things. First impressions are that bass is slightly less tight and tuneful, as well as imagery is slightly less focused (and these are, for sure, strong points of the SOVTEKs 12AX7LPS), and the above mentioned aggressiveness has gone (at least hearing the same records on same chain).
One of these days I’ll try the SOVTEK 5751s, said to be constructed the same way as the LPS’s.