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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!  
jbhiller
jbhiller's avatar
jbhiller OP
464 posts
 
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. 



samzx12
883 posts
 

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.

aniwolfe
544 posts
 
@ 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.
samzx12
883 posts
 

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.

aniwolfe
544 posts
 
@samzx12

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

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