Rolling KT150s in Primaluna hp integrated

I’m approaching 2 weeks into this tube roll and I have a better understanding of what the KT150s do.

The KT150s in the PL Dialogue Premium HP are a great match. It’s not easy to go back to other powertubes. I had to for a day as I dropped one when taking it out. In this amp (in my room, etc.) the KT150s just sound better. The power allows imaging and soundstage to be bigger and more controlled. The bass is without question more robust and controlled than I’ve ever heard with tubes or with 2 SS integrateds with my speakers. 

While I can’t say what others would like, I can certainly say that rolling KT150s in this amp create a big change. It’s really something owners should experience. I think the change could keep me out of the upgrade game for some time as it’s made such an improvement in sonics.

Using a combination of Mullards and Ciftes 12AU7s in the first four slots with the KT150s really dials things in to my liking.

What’s kind of surprising is the KT150s are not edgy, harsh, bright, etc. They just add more dynamics, control, authority, size and precision to imaging.

If anyone wants to buy a matched octet of Gold Lion KT88s, which I purchased from Upscale (not cyroed), PM me. They cannot have more than 300 hours on them as they are less than a year old and I ran them in rotation with 7581As, 2 types of EL34s, and now the KT150s. Such a great tube that I don’t think I’ll use with moving in the KT150s.

jb
I totally get your excitement, I have been in the same boat with the PL HP Integrated and rolling the stock PL pre 12AU7s to NOS Mullards/NOS Brimars and the EL34--> KT88s. 

As you said, swapping out the first 2-4 pre tubes makes critical sound changes, for the better for sure. I have floor standing speakers, so my next move would be to move up to the KT120s and keep the Mullards in the first two inner pole positions of the pre tubes, followed by the Brimars, then the 2 stock tubes. Since the KT120s would spread out its energy toward the highs/low, the Mullards would fill in the mids nicely.

But alas, I live in a place without AC that gets so hot in the summer that tubes are now "temperature-prohibitive". I will be having to sell the HP integrated to go to Class D ... scary.

1graber2

Same here.  I am planning to get a PL HP w/KT150 but my concern is the temperature.  Summer in Los Angeles can be as high as 107F.  Can you guys share your experience on how hot the amp gets with those tubes?  Many thanks!

Can you guys share your experience on how hot the amp gets with those tubes?  Many thanks!

From the EL34's 6amp to the KT150's 8amps there will be substantial heater temperature dissipation, if the heater voltage stays at 6.3v and doesn't sag under the extra load that the 150's will put on the filament supply.

Cheers George  

There is no issue with the load imposed by the 150s in this amp. The manufacturer endorses after it did significant testing before doing so.

The power transforners on this amp are massive. That’s why it weighs 60 plus lbs.

With respect to room heating, I live in Chicago so we see all sorts of temperatures from 10 below to 95 to 00 every year. Smaller EL 34 Tubes in their substitutes do not cause too much significant heating in the summer months. But it is definitely noticeable. I went the route of buying a class D amplifier last summer and moving the prima Luna to the basement.

Let me just say that after six months, I sold the class D amplifier and brought the prima Luna back up. I don’t know when I’m going to do this summer. The sound is to to die for so I’m just not sure. I might not care s out the heat. Or, I’ll buy a nice used integrated.

I didn’t have the opportunity to audition all different makes of class D amps. But the one that I did evaluate was not able to impress me long-term.