EL34 & 6L6 characteristics

I have no specific suggestions, but for everyone's info the Primaluna Prologue II is apparently supplied with KT-88's, with the manual indicating that 6550's and KT-90's can be substituted, and that "you may also use EL-34, 6L6GC, 7581A and KT66 though power will drop slightly."

Regards,
-- Al

Saki,
I used the Shuguang Black Treasure 6CA7 in my Primaluna Dialogue One. It sounds to me to combine the best attributes of my NOS Reflector 6n3ce (6L6) and my NOS RFT Siemens EL34. Better detail and air, yet full, a drop of warmth, increase of quality bass. Generally all around better in my system. The Simens are also good performers. You might also like the Bugle Boy 12au7s in combo with Sylvania 5751 3 Mica Black Plates in the Primaluna. I know I like them a lot.

Mikirob ;
I have rolled the small tubes to Mullards for the ax's and radiotechnique for the au's and they made the biggest difference for me . I have lived with the EH EL34's for quite a while .
How plentiful are those Shuguangs and Siemans 6CA7's ?

Thanks

Saki,
The Shuguang Black Treasure 6CA7 is available in quantity from Rachel at Grant Fidelity. Likely about $300 per quad. Grant stands behind everything they sell. I also believe Trelja here, at Audiogon sells this tube. The RFT Siemens EL34 is harder to get and can be costly. I paid about $200 for a matched pair from Brent Jesse and $150 that matched well with the Jesse tubes from a friend.
I have also used the Mullards, very nice in 12ax7 position. I forgot to mention mention that I used the Gold Lion KT77s. Again, the Shuguang Black Treasure did it for me in both the Primaluna as well as my Coincident Dynamo 34SE. Best

David, most 6L6 vs EL34 comparisons EL34 come out the reverse of what you listed. Then again, EH tubes often sound among them most lush in the spectrum.

Generally, I would stick with the EL34, but try other brands. JJ E34L will come across a lot more as you described the 6L6, and in the right amplifier put forth an absolutely glorious midrange that almost nothing else compares to. JJ and Shuguang EL34 will track closer to what you described the EL34. These three tubes will come in at quite modest cost. EH 6CA7 will present the most slam, though in an easy to live with presentation. Shuguang Black Treasure and old Mullard do sound a better than the others, though at a higher price.

Of course, the amplifier itself plays a role. Your PrimaLuna features autobias, which provides a lot of convenience, though some implementations do not yield as much sonic flexibility as others. I've not lived with a PL amp, so I don't know how they react. With an amp where you adjust the bias, you can sometimes better dial in the tubes to your taste.