Primaluna Prologue 2 Upgrades

Thanks Davide256

Yes, I may sound Mad, but, this is end station in tube rolling and if the OP would like to know what to do to make it better, why not this option, even it sounds crazy. You can find them in UK, some NOS, some used, but good testing, price depends and will be around GBP100 each, maybe more. There are places where you can get them in US to, but I am not sure about the price these days, as I bought them in Europe.

There are EAT KT88 as well, but I dont know if they are worth that kind of money, never tried them, besides, EAT do not build them, probably KR does, as their 300B to.

A quad of new factory matched KT120s should cost around $175 unless cryoed or something...I bought my set from an Ebay store a year and a half ago and they're still working and sounding great with no audible sign of wear, bias drift, explosions, or fatigue (hell, I'm wearing out faster than these tubes)...a bargain as far as tubeage goes.

Looks like "Maxmad" acts as his screen name. GEC's are like a holy grail of tubes, probably about the same cost as the OP's amp in total... if you can find them. The Tung-sol KT-120's cost about $240 for a quad and blew away handily the Gold Lion KT-88's which I paid more for and in the past year.And while EL-34's sound sweet, I really can't live with a tube that snoozes on percussion.

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.

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.

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 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

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

Replace the original KT-88 power tubes with KT-120's if you do nothing else. You will get significant improvement in bass and detail. Prima Luna OK'd the 120's use in all their amps at the beginning of 2013

Not parts, but I rolled tubes and the improvements were fantastic. I used all NOS made in UK around 50's Mullards / Brimars in pre and driver sections plus UK made NOS GEC KT88.
The tonality of amp become miles ahead from stock tubes, its like day and night, thats all I can say.

I had a tube pop and glow red so i sent it to mitch singerman at Kevin Deal's recommendation. While he had it i asked if there were any upgrades he would recommend and he suggested replacing the Solen outputs caps with Musicaps. since it was there and apart. Only cost me $100.00

Did it make it sound difference? Seemed a little smoother but not a huge change.

more change with tube rolling