My first tube roll in a Primaluna Dialogue HP Integrated


First off, special thanks to tomy6--a fellow audiogoner who helped me identify, with specificity, the exact tube I was swapping in:  an Amperex 12AU7 tube made in the early to mid 70s; Great Britain Mullard factory. 

I swapped out stock Chinese sourced Primaluna 12AU7s--6 of them--from the preamp section. 

The process of rolling and twisting in a gentle swaying motion is really easy, yet there's an subtle art to it.  By the time I hit my 3rd or 4th tube, I got the hang of it.  In my mind's eye, I had a vignette of many folks who came before me, installing tubes.  I pictured repairmen with--what I think they had--a tube caddy, full of tubes separated by cardboard dividers like bottles of wine.  

I didn't bother to clean the somewhat oxidized-looking tube pins, which were much darker and tarnished than the 2016 Chinese Primaluna 12AU7s.  I rolled one set out, and dropped the other in. 

It was interesting to see the Amperex tubes flash up on startup.  I wondered if they were going to blow!  They flashed brightly and calmed almost as fast as they lit up.  My pessimism nearly expected the amp to signal that I had a bad tube or two.  Primaluna's autobiasing automatically kicks in and handled that--just like Mesa Boogie guitar amps.  

Things sounded just fine out of the box. I'd say no better or no worse than swapped tubes.  I've been running them now for 90 minutes.  The difference is real yet subtle. Here's what I think:

--The Amperex tubes have more top end attack.  I wouldn't call it bite. There's more detail on top....not much, but it's there. 
--The Amperex may be less warm.  The bass seems to be more defined but there's less of it. 
--The Primaluna's sounded a bit bloatier, which was kind of nice in some ways, yet in another it's making me thing and digest these differences. 
--While the soundstage of the Amperex seems to go back deeper than the Primaluna, it seems like I'm sitting a bit farther back from the performance.  I cannot tell which I prefer.

I haven't had a chance to really crank the volume and get them heated up and pumping.  

I have no strong takeways from this experiment yet and I certainly haven't decided which I prefer.  Next up is a set of 6 Ciftie military grade set of 12AU7s.  

Different indeed!  


128x128jbhiller
saki70-
your insight is appreciated. Guess I will pass on those. I have a hard enough time really picking out the subtleties between the 4 brands I have on hand.

Presently rockin with a full rack of RCA glass:6L6G coke bottles and a row of blackplates. Clean and clear with plenty of energy of both ends to the spectrum.
I'll just leave well enough alone and contemplate new speakers sometime this year.

tablejockey ;

That sounds like an excellent decision ! Contentment is so underrated compared to upgraditis ! LOL .

Myself...I am content with Shuguang 6Ca7's and vintage 7316's . Very extended , clear , detailed and above all musical .

Happy Tunes

After years of hardly listening to my venerable PL 7s"10 yrs" and Pl Premium Pre"about 3 years old" i decided to swap out all the tubes to try them out. Hearing that a new pwr tube was out Kt 150, i was excited to try it but alas checked PL website and it was a no go. So i went with a matched octet of tung sol kt 120. These sounded terrible to me and was hard to wait for them to settle in often turning them way down as i could not think with them in the background at the office. 2weeks and 24/7 of leaving them on they started to smooth out. They replaced a set of goldlion kt 88 that i really liked and was starting to regret my decision. As all i got was a tighter bass, softer mids and thinner highs. 

So now that im stuck with the 120s, how do i go about rollin the signal tubes? I read that all the signal tubes in the Pre make a big difference not just the front 2 in the v1 position, and that only the front 2 12ax7 in the pwr amps would help , with the rear 12au7 making not much change. I want more 3d larger than life soundstage, with airy highs and more prominent silky smooth warmer midrange. I am willing to mix and match all the tubes and i am open to all suggestions.

Currently i dont play the records no more, cause i got too lazy to change them constantly, and now have gone digital 100% I use a PS audio perfectwave DAC with bridge ii, and an old idecco for iphone listening as well for the all tube effect. Speakers currently are Opera seconda ii, or SF Liuto or Wharfedale Jade 7s, all these are great tube players IMO. All wires and pwr cables are good enough. 

The tubes i have are sylvania "baldwin" 12au7 on the pre, philips rectifier which adds a tad of warmth, IMO should have stuck with the PL rectifier. on the pwr 7s mono, reissue goldlion 12ax7 b??? and RCA cleartops. I could borrow some Mullards 12au7 from my Ayon setup in my living room, but they look so old im afraid they would just break off. Everytime i turn that on the getter flashing scares me.  

After reading many posts and not working in my office, i have concluded that some tubes cost way too much and do not want to go there. So these are on the shopping list to try, Amperex 7316 , Telefunken 6211, Brimars 4034, Ei 12ax7, siemens E83CC, Slyvania 5751 or RCA BLACKPLATES. So if anyone can best help me not buy all and try, my child may go to private school for another month.
thanks in advance.

Sorry for hijacking the post , as mine is a question for suggestions and help. 
aionlim-the authority on PL  is the distributor @ Upscale Audio.

Kevin also sells a  bazillion tubes, he can offer insight on the tube rolling thing.