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
One more thing--

The Amperex do not show as great of a sound difference when I switch between triode and ultralinear settings.  Not a good or a bad thing...just a thing.
"Next up is a set of 6 ciftie military grade set of 12AU7s."

I don't have an extensive collection of different NOS, but do hear the subtle refinements of the 2 preamp(innermost). The 2 other stages don't seem to be as sensitive to rolling. I ended up changing all of them, just for the sake of continuity. Mine are a row of 50'sRCA blackplates. Now and then I switch the 2 innermost with Raytheon and the Mazda(Cifte)

I have a shoebox full of old American tubes from years of guitar amp spares.

There does seem to be audible differences with generic new tubes and NOS. 6@$50+ is a little steep for the euro fancy glass, so the RCA I purchased for $5 each work.

Once you start playing with NOS, IMO the subtleties are even greater, and don't warrant the high cost. Or likely, my hearing is just aging like the rest of me.

The Power tubes are what can be the real wallet killer. I've seen a little price discount for the KT150, but $800 is just out of my league when it comes to lavish spending.

Regardless, enjoy the roll.
--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.
Your observations are spot on. If these tubes are new, they will require a burn-in period.
The Amperex do indeed have more air and detail on top. They are not a warm tube, but should sound full-bodied. I have never owned the orange label Amperex, but their Holland factory tubes have deep bass extension so maybe your's need more time.
Wide, deep soundstaging is what these tubes are all about. Hopefully, you'll like their spacious presentation. If you do, in the future look for the "Bugle Boy" version which are their top of the line tubes.


I'm about 2-3 hours in and bass is more prominent and they sound less bright.  The detail and soundstage is great.  I'm going to let them burn in for 15-20 hours before I critically review them.

Thanks for the background and advice.  
You are going to get a lot of recommendations for the expensive and rare tubes on Audiogon.  If you don't want to spend the big bucks, start with some American brands readily found on ebay.  I will let you in on a secret. The older Raytheon black plates were terrific.  I then swapped in Raytheon Japan short gray plates and they were as good.  In my preamp circuit, these beat out the brands with the lofty valuations.  The best part is they are easily found under the Baldwin organ label and were screened for low noise and microphonics for Baldwin.
@rotarius ,

It's interesting to me you said that.  I'm a guy who likes to learn for himself so I had a thought similar, very similar to this.  I bought NOS Amperex, Ciftie, and used tube pull Baldwin brand tubes.  Here's a photo of the Baldwin:

http://i61.photobucket.com/albums/h61/jbhiller/Baldwin%20Tubes_zps8nw9ev2a.jpg?t=1487890945

Are these what you're referring to?  They are coming tomorrow.  Only $60 for the 6 I need for my preamp section.
@jbhiller ,
Those look like Sylvanias.  Those are pretty nice although not as warm as black plate Raytheon or RCA.

Update on the rolling of Amperex 12AU7 Mullard, Blackburn, Lancashire factory tubes (orange world, mid 70s vintage):

I've got a good 12-15 hours on the tubes now.  The high end is more extended than the Primaluna 12AU7s and it is certainly clearer. 

The bass has come on nicely; there's plenty of it and it matches the Primaluna 12AU7s in quantity and has better defined form. 

The tubes sound warm enough, strong and detailed.  I surely prefer them to the stock ones.

One thing that has proven interesting with them; with these tubes I like streaming via Tidal to my DAC better.  Everything sounds crisper and more alive, and they closed the distance between my vinyl rig and digital.  Vinyl is still preferred and better overall to my ear, but digital is definitely more tolerable. So, this makes the investment all worth it.  I'm excited to hear streaming music whereas before I hadn't used it very much over the last 6 months because vinyl was upstaging it significantly.  I think I'd have buyer's remorse or felt I learned a tough lesson if the NOS Amperex didn't sound as good as what they swapped.  

Oh man!  I'm now a curious tube roller.  
"..and used to pull Baldwin brand tubes"

Jbhiller-if you're not already familiar:
http://www.audiotubes.com
Reasonable  pricing on tubes. Especially the cosmetically imperfect, otherwise fine RCA,GE brands.


Jbhiller, if those sylvanias turn out to be usable, please let me know your opinion and comparison to the Amperex ones.  

If you like the Amprex tubes from Britain you would love some 7316's !

I use 4 of them in the top 4 positions and the Primaluna's in the bottom 2 positions  . The bottom 2 positions ( nearest to the front) don't really benefit

from rolling . The 7316's are probably the priciest of the bunch though .

Good Luck

"the bottom 2 positions (nearest to the front) don't really benefit"

saki- do you mean to 2 INNERMOST positions?
its always been my understanding(per distributor/most of discussions) is first stage L/R channel of the preamp circuitry(the other 2 are do other technical stuff)that do make audible sonic difference(good or bad)

I find this to be the case. YMMV...its audio. 

If you do hear as stated, go with it.
@rotarius 

i certainly will  I cannot get the amperex out as they sound sooooo good. 
7316s are Amperex premium 12AU7s.  I have some labeled Mullard, but they were manufactured in the Amperex Herleen Holland factory.

As good as these 70's Mullards are, most people think the early 60's versions are even better.

On the more affordable end, RCA and GE 5814 blackplates from the 50's are nice.  The 5814 is a mil-spec 12AU7.

I also like the German RFTs that are typically labeled made in England.

I'M SO CONFUSED !!!

tablejockey ;

Thanks for catching my mistake ! You are right !

So sorry... I meant the outer most tubes . The one on the extreme left and the one on the extreme right . 

Happy Tunes

Has anyone tried the Brimar 12au7 in the 2 L/R slots? I understand it to be a nice tube. Impressions?

I'm not familiar with your circuit but auto-biasing is related to the power tubes not the driver tubes.

tablejockey ;

I found the Brimar/ECC82 to have better voice delineation than Amperex with about an equal guitar portrayal . Also it had less top end extension but a nice sparkle , liveliness and air although not as musical as Amperex and RCA clear top . Kind of like a lessor CBS .

This is from my notes of a couple years ago .

Happy tunes .

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.