Primaluna - Rolling pre tubes question...

Learsfool, I had the same experience, after rolling all of the tubes in my monoblocks; I quickly put the 12au7's back in.

Dmhenley ;
I am sorry the Cifte's didn't work out for you .
If the price doesn't scare you... try some 7316's in the input section . Far & away the best that I have tried to date .
For less money you could try Amperex made by BEL in India which would give a good taste of the 7316's . Both of these offer a warm tone . The BEL's may be around the same price as the Cifte's .
Amperex 12AU7 D getter long plates were not to my liking in this position . I have not tried Mullards with this amp but did use them in my previous amp , a Prologue II which used 12AX7's for inputs .
I tried Amperex Valvo's for drivers and they didn't work out either . The Valvo's tended to take away what the 7316's brought in , as did others that I tried as drivers .
I have not been able to find other tubes for the driver section that don't detract from the various input offerings .

Learsfool & Orpheus10 ;
I have been thinking along those same lines concerning the PL 12AU7's , they seem to be rather neutral also . They allowed me to here a large difference between the KT-120's and the 6CA7's when used as inputs . The difference was less prevalent with other tubes rolled into the input section . So far they are the best drivers that I have tried , allowing me to hear all of the different tubes that I have rolled .

Saki70 -
I do like the Cifte's, but I did lose some presence in the mids and upper bass. Much like all of your experiences were, I found swapping the stock PLs back in brought me back where I want to be.

Eventually, I will continue to experiment - this is all good education for me.

I think I'll enjoy the music for a bit before I go down the rabbit hole again.

Thanks again

That's cool...you may find that what you have ain't so bad !

Happy Tunes

I'm about to put up some info on the PrimaLuna website about this. First, in preamps all the small signal tubes have an equal effect on the sound and you can change out just one pair if you want.

On power amps and integrated amps the two 12AU7 (in older models 12AX7) that are in the center are the input tubes and they have gain, so they will make the most difference.

I've spent a lot of time on this. The stock tubes are surprisingly good sounding. Fabulous. The French-made 1962 vintage Cifte's will have a little more extension on top, and that's why the mids are not as up-front. But that will change in time. They have a lengthy break in period. I would say a couple hundred hours. But really it takes longer than that.

I've been running 60's vintage Mullard M8136 and they are really nice. I don't know if they are for me exactly. They have more body. The mids are fuller and pretty. But the reason it sounds this way is because it's more laid-back on top.

I've also tried some British-made Brimar CV4003. These are hard to find, but we recently scored a nice quantity of perfect ones. I've always liked them. They are between the two above.

I have customers with really good ears tell me that they love the stock tubes and I agree. I hope this helps. If you guys have questions on this it's really great to put them up here or audioasylum as others DO benefit even years later from your data.