Has anyone compared K150 tubes and the stock EL34s in Primaluna integrated/amplifiers?

I have a Primaluna Dialogue HP Premium with stock EL34s.  When the EL34s wear out, which I suspect will be a long time, what would I replace them with?  The KT150 is intriguing to me. 

Has anyone compared these tubes, especially in Primaluna gear?  I'm wondering if I would lose the EL34s midrange in exchange for the increased power of KT150s.  It's hard to find, however, a bad review of anyone using KT150s. 

Thanks all!  
i too have the dialogue hp premium and was thinking the same thing.  with the hp, i dont need the extra power, but have heard great things about the sonics.  i was also wondering where the kt120s fit into the picture sonically. 
Curiosity is killing me!  Kevin Deal at Upscale told me the EL34s have the best midrange, yet others seem to like the 150s over them.  
I was running the EL34 to Revel Performa3 F206s. Maybe not as power hungry as the Performa 2 series, but still not quite lighting them up.
So  I got the KT150 and Boom! Did the trick. I love em. Might add that the  Mullard CV4003 for the 12AU7 is freakin wonderful. (I hesitate to say it because Upscale has already raised the price since I got mine a few months ago.) Subbing those tubes out is a $1500 proposition but well worth it IMHO.
BTW the ultralinear mode has a bit of an agressive edge to it, and I hear reviewers saying they prefer the triode mode. With the Mullards the ultralinear mode is smooth as can be, and I never prefer the triode mode now.
With that combo, it is better in every way you want to list. And the bass is amazing. Hard to believe that kind of bass from a tube amp.

I have the Dialogue Premium rather then the HP .

I have found the Shuguang Black Treasure 6CA7's to be to my liking . Your stock EL-34's are quite good for that type of tube . I have tried many different brands of EL-34's .

I have also tried the KT-120's . They have a nice top and bottom range but I found them lacking in the midrange . The mids are where the EL-34's tend to shine .

Some of my journey , into tube rolling with the Dialogue Premium integrated , is documented here in 1 or 2 threads for both the power tubes and the small signal tubes .

Good luck

Saki70 which EL34's have you tried? What about Gold Lion KT77? How do the Black Treasures compare to the stock PL EL34? For example, tone, bass, extension, etc...?

What I have found so far is the stock tubes sound very good and the overall timing or cohesiveness is almost spot on. With some other power tubes I have tried the cohesiveness seems to be a little off. Did not like the KT120 AT ALL. Midrange was dry and etchy. I do have some KT150's and they sound MUCH better than the KT120. I do like the 150's but I am getting used to them. The voices and some soundstage seem to be more recessed or pushed back than with the stock EL34. However, the bass, punch and drive definitely has more impact. The 150's do sound very nice but ARE different than stock EL34. I will say this is they have more of an EL34 tone which I like.

I'm thinking of a Primaluna. How much of a sonic difference between KT88 and EL 34's?

samzx12 ;

Search Audiogon for my threads on this subject . The EL-34's are named and the results listed .

Happy Tunes

Question. Any tube sets (kt88,el34,etc) that are better for low volume listening? Probably 30% of my listening is at low volume. I currently have a Pioneer EQ that I switch on ( true bypass switch) for low volume that fills in the low end. I plan on keeping it in the chain when I go with tubes. 

Just bought a lightly used matched quad of Tung-Sol KT-120 for my Primaluna Dialogue Premium. Initial reaction is wow, where did all that bottom end come from?   Next reaction was where did that sweet accurate midrange go?  
Looking for something in between. KT-88 maybe?  
I still have a lot of listening to do before I really get a clear opinion on the KT-120. If you are looking for extra punch the KT-120 makes a positive initial impression. 

that's good to hear because I want to avoid losing the midrange sweetness too.    

I'm wondering if I combined the KT120 with Cifte 12AU7s what would happen to the midrange.  Did you keep the stick 12AU7s when you replaced the EL34s?
I'm going to try the following by next week: 

Pre-amp section:  Swap out stock 12AU7s for new old stock Siftie 12AU7s 
Amp section: Swap out stock EL34s for reissue Mullard EL34s.

I'll follow-up with thoughts asap.
What did you think of the Cifte 12AU7 and reissue Mullard EL34 JB?  I tried this combo and found it sounds very good but lacking in bass weight. Overall the sound was very clear and concise but the Mullard doesn't have the bass of even the stock PL EL34.
@ samzx12

I have had the Mullard El34 Reissues in the PL Dialogue Prem Int Amp and felt the bass was ok. My biggest issue were cymbals(high freq) sounding rolled off at times. I then ordered the GL Kt77 and felt the treble was excellent and so far the bass is a little bit better, but I still need more break in. I only have about 70hours. Supposedly they need over 100hrs for the bass to appear.

I just recently got Cifte 12au7's. They have over 100hrs on them. I was surprised how smooth they were. I find them to be very musical. I was expecting from everything I read to be a thin, overly revealing type tube. They are not the thickest sounding , but are also not what I would call thin. I feel they are JUST RIGHT.
Great question regarding the Ciftes. 

When I had 4 of the 6 tubes being Ciftes, I felt that the sparkle and top end air were great but I felt there was a need for some syrup in the midrange and the low end was more subtle. 

I found two combinations worked well. 

1. Center two slots Cifte 12au7s, next inner two slots RCA black plates, and outer two slots any decent tube. 

2.  Center two slots Cifte, next four slots stick Primaluna 12au7s. 

This was kind of a blessing discovery because 6 Ciftes across the board are pricey. 

Just 2 Ciftes seems to be right in my room with my setup. 

Now, I can't say too much about the Mullard reissue EL34s as I had them in s week and then Gold Lion KT88s in for about a week. I will say though that the reissue EL34s were great to my ears, same as the GLs. 

I was was really surprised with the reissue Mullards. They sounded great to me. Tighter and more control than the stock PL EL34s. 

The KT77 is a good tube with plenty of bass however, I didn't hear it takes that long to break in.  I will take your word for it. Maybe the Mullards need more break in time but its noticeable that it doesn't have the bass output of the stock EL34 or KT77.  Aniwolfe what kind of speakers do you have?

The Cifte in my system do sound well however, they don't have the lushness of some other 12AU7's I have tried. I put in some Psvane in the front slots with good results. I will add that I got some GL KT88 and letting them break in and boy do I have some bass now.  Its too early to tell and will report back once they have more hours but so far the mids are nice. Not quite the stock PL EL34 but nice.

@ samzx12

Yes from everything I have read the Kt 77’s take 100-200 hrs for the bass to appear. My speakers are Eminent Technolgoy Lft-8b’s.

I’ll trade lush for some more air and separation with the Ciftes so far one my favorite 12au7 in the middle slot. I do like however the Tungsram 12au7 and the NEC Mullards quite a bit also.

Thanks for the heads up on the KT77 :)  What are the characteristics of the Tungsram?  The Mullards in my system while sounding ok seem to really deaden the sound or its like someone placed a sheet over the speakers. I am speaking of CV4003 NOS Mullards I bought from Kevin at Upscale. Do your speakers tilt to the warm side or cooler side? I have Tyler Acoustics newer Highland series and the tweeter is very revealing without being bright. The rest of the drivers are SEAS.

I do agree the Cifte's have air and separation. Really good tube. I did replace the stock PL AU7's with reissue Tung Sol and they are breaking in but they helped with the upper midrange glare I was getting with some recordings.


The Tungsram have a neutral smooth sound like the Ciftes but more bass and less air.

The NEC Mullard Longplates are more neutral than your classic British Mullard. They were made by NEC in Japan using Mullard parts/tools. Labelled Hewlet Packard. They are really amazing. Some for sale NOS on ebay, seller name I think is Spincards. Very reliable person to do business with. They are probably my favorite 12au7. Great soundstage, nice extension on top and bottom. Mids are glorious

aniwolfe thank you very much for the Mullard and Tungsram advice.I will check out the seller on Ebay. Happy listening.

I'm curious with your opinion concerning GL KT88 vs the KT77. I tried the KT120 and found them a bit glaring. I too, like aniwolfe, am using KT77 with Cifte tubes in my PL Dialogue Premium which sound wonderful. I'm using Cifte in the first 4 slots with the stock PL 12au7 in the last 2 slots. 

Keep us updated with the KT88

Ron I need to listen more to get a good grasp on the GL KT88.  So far they are favorable. Great bass control, top end extension is good with no brightness,  mid-range is nice but I'm trying to find the correct 12AU7 combo. The Cifte is in the front two and reissue Tung Sol in the last 4 slots. I am liking it so far and I will say this. I like the GL KT88 better than the KT150. For some reason the bass is fuller and stronger. YMMV but maybe the amp handles the 88 tube design better than the 150? Kind of shocking and I feel I have several hours on the 150 to get a decent feel for them. Maybe they need more time? Not sure how long most people feel they need, but I think with any tube after 25-50 hours one should get a good opinion or feel of the sonic characteristics. 
Just a quick update. I put the stock PL 12AU7 back in the last 4 slots in place of the Tung Sol and prefer the stock tubes. Also replaced the Cifte with NEC Mullard 12AU7 in the front 2 slots. Not sure what to think at this point the NEC have more definition and transparency. In other words more energetic without being bright.  Sill haven't rolled other power tubes yet for comparison.  
could you tell what kind of speakers are You using with Dialogue HP ?
i wondering if this amp can run such speakers like AP Virgo V

Little late chiming back in on this thread, lots of music to listen to 😀

I am am now running all Gold Lions in my Primaluna. Six of the ECC82/12AU7 Gold Lion reissue and four KT-88.   Beautiful mids and highs, bass is deep and accurate when the recording delivers it. Very accurate, very happy. 
Have tried quite a few tubes in the HP Dia prem.

The other nice sounding tube if you like the warmth of the EL34 is the re-issue Mullard KT88s.

great midrange on that tube.

would also suggest the EL 6CA7 Fat bottle. very musical sounding tube.

have also tried the Tungsol 6550 and KT-120s. Both are a great match for the amp, and sound extended on the top and bottom but do not have the midrange of the Mullard '88s or the EL34s.

the other tube not to forget is the first input tube, 12au7. Rolling in a NOS Mullard or other desired choice has a large effect on tonal qualities.

Timely discussion for me.  I recently purchased a the Dialogue Premium HP Integrated, and I'm thrilled with the sound quality of the stock tubes. It's also the quietest amp I've ever had in my system.  I just ordered the KT150s and NOS 12au7 Mullards.  Can't wait to try them out.  I am running them with Harbeth C7es3 speakers in an all analogue system.

Will let you know how it all sounds once they arrive.

Best, Scott
I have I have the hp dialogue premium power amp and was amazed at how dramatic the improvement was by using NOS mullards 12au7s in the v11& v12 positions.  The soundstage was so much bigger and deeper into proac monitors, which have a great soundstage to begin with.
FWIW ..  Before plugging in a higher output example of the 6550,  PLEASE insure the amplifier design will handle the higher load.
Contact the designer of the amp and ask them if there may be a problem.  Without question, it WILL be a tearful experience when flipping the switch and not clearing the launch pad..  pc
I just realized that I hadn't followed up.  The KT150s are really amazing.  I have been using them for a few weeks, and I just keep smiling.  They provided both power and finesse with a great soundstage.  Nice bass, and an amazing midrange.  Very coherent from top to bottom.  Highly recommended.  

I just may try the KT150 in my HP after hearing the results of this thread. 

Not being able to use the cage however, is a negative. Maybe no big deal since I don't have any small children/pets running around.

In my opinion, everyone commenting about sound quality on a dual-mode amp like the PrimaLuna Dialogue Premium should indicate whether their observations apply to ultralinear mode, or triode mode, or both, if that is the case.
I've only run in ultralinear with KT150.  Have Revel Ultima Salon 2, and have a VTL TL 7.5ii pre using 12AU7 tubes I like for their neutrality (I think they are PSVANE - essentially sorted out chinese tubes).

Sounds is very fine, and I have not felt the need to tweak.  They warm up and we are off to the races with sweet (but not drippy rich) tonality from bass to treble, definition with out etch, dynamics (maybe a bit wobbly on bass if its hit hard, but with a musicality that covers the loss of ultimate control).  Love the sound.

I assume the GL KT88 are fully broken in so what is your opinion vs the GL KT77? Since you indicated the 88s have better controlled bass and top end extension, what about the mid range? 
Yes I tried the 90s when I had my Dialogue PL Premium and did not like them at all.  Felt as if a blanket was over my speakers.  YMMV but felt it was horrible in this amp.  

Resurfacing a six (6) year old thread after a friend asked me a question today. Some old comparisons here - thought I'd give the post a try and see :) Since I don't have any KT77s lying around, only KT120s, KT150s, thought I'd try a post here. Does anyone here feel comfortable remembering back or reporting out by chance -

The ask, for a friend:  

"has anyone on Agon compared a KT150 to a KT77 in their amps before", pros/cons of each, what do you hear comparatively?: