Primaluna Prologue 2 Upgrades

I preferred the EL34 in the PL2 and in fact ran a combo of winged c's and new sensor mullards.

I too rolled the input tubes to Mullard for the AX7's & some French 1956 military's from La Radiotechnique for the AU7's, as suggested by Kevin Deal . The AU7's were not as important as the AX7's .
These made a huge difference in the warmth and tonality of the sound . They did not affect the great top end extension but did increase the base a bit . It also responded favorably to the EL-34's by Electro Harmonic's . The people at Upscale Audio stated that a power chord upgrade did not do much and therefore did not recommend it .

These changes increased the warmth/tonality , which is what I wanted to do . I felt that the stock tubes tended to make it sound like a SS unit . To me it is better but not generally what someone is looking for when trying to upgrade parts . For that type of better I would just change amps all together . You did not state what type of change it is that you are looking for with the upgrade .

Good Luck

Thanks for the replies.

I have gone through the tube changes, have Mullard NOS input/driver tubes and Svetlana EL34 output tubes. As you say Saki70, it does make a difference to the performance character of the amp, much more preferable to my ears.

I was really asking if anyone had done any major component changes such as cap and resistor changes to, probably, better specified/quality components.

The Prologue 2 is such a great amp once the tubes are changed to other ones, I was wondering if anyone had taken it any further, or whether it is possible to improve the performance.

I recently put a pair of Psvane 12AX7 T IIs in a Jolida and they sound great...clear highs and tight bass, with an overall clean presentation without tubey artifice. There was nothing wrong with the Tubestore "Preferred" 7025s I had been using but was interested in a roll for my own amusement, and I am sold on these tubes. Note: get these from the Canadians as I had some issues with the Chinese Ebay dealers...resolved but took a while.

EL34 NOS Tesla's were very good, but not at the level of NOS GEC KT88, so, before you do any change, I hope you have the funds to do that roll. KT88 are simply much better tubes, power and delicacy, where EL34 cant match.

I also tried NOS Tung Sols 6550 Smooth Black Plates and Sylvanias, but again, KT88 GEC's simply eats them for breakfast.