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Prima Luna Integrated - EL34, KT88, KT150, Brimar AU - My experience

Thought I would help out some who are considering rolling some tubes ......
Prima Luna Dialog Premium HP Integrated Stereo

Stock EL34 - Chinese I think
JJ/Slovakia KT88 - from ARS
Tung Sol KT150  - yep, these are it, and worth it, do it.. purchased matched from Upscale

First, I have to tell you, I LOVE this amp.  Prior to this, I had a pair of monster VTL Deluxe 300 monoblock tube giants.  In short, the VTLs were less veiled... but the PLs are so musical, believe it or not, better bass! yes, true. and way more fun to own given the tube rolling flexibility.  (I only use the amp in ultralinear, higher power mode).  Oh, and the auto biasing feature - no more burnt fingers or back twists!  BTW, VTLs were a pain and flaky - still loved them and owned them for about 15 years.

The PL comes stock with (Chinese I believe) eight EL34 power tubes.  Out of the box, the amp is stellar.  Why did I try rolling tubes?  Well I have a big stock of power tubes left over from my VTLs.... KT88s ... so after a few months of using the amp as stock... I tried the KT88s.  These KT88s are labeled JJ/Slovakia and BTW, Upscale said to me they won't carry these KT88s from JJ because "their quality control is awful".  Anywho, I put them in anyway. 

EL34 = beautiful.... just a wonderfully musical tube - nothing wrong here - PL did a good job choosing this tube
KT88 = more dynamics, a bit more power, better fuller bass, but something was a bit wrong on the top end.... had an odd edge up there.  Overall I am not sure which I liked more.... the EL34s are perfect but I liked the more dynamics and bass of the KT88.. but their top end ... hmmmm..... I would switch them and therefore hear their strength and say "these are better"... then I would switch and say the same thing.  Issue was there were trade offs.
KT150 =  This is the tube you want.  Compared to the EL34... a bit more dynamics, less veiled, much more power, deeper bass.  Sounds very linear top to bottom.   The only negative of the KT150s over the EL34s... I think the EL34s were a tiny bit more musical... but the KT150s are very musical themselves.  Overall, the KT150s are staying put.  Done.
More to the story.... before I purchased the KT150s I traded emails with Upscale... we discussed the JJ KT88s... they suggested swapping out the front two 12AU7 gain tubes with Brimar CV4003 NOS (made in the '60s).  So I did... and I hated them!  OMG.... they did something to the top that made my ears bleed.  I really let them break in but I had to pull them out as I just couldn't take it.  Now this was with my JJ KT88s.  Upscale responded to me and said I was the only one to complain and describe them as bright.  So... I put the amp back to stock.... listened for a few weeks... then I put the Brimars in with the EL34s ... well OK, much better.. but I still am not sold on the Brimars.  I did learn that my KT88s really do have something bad going on at the top end given these Brimars screamed their issue.  So.... let's buy some KT150s from Upscale.

Note: Upscale said that many like their KT88s over the stock EL34s due to the dynamics and bass improvements so apparently, these JJs have a sonic characteristic that is different than other KT88s.  Maybe.  If all KT88s sound the same, then I can't recommend them.  If they don't all sound the same, then I can say strongly, don't bother with the JJ/Slovakia brand.

I have not tried the Brimars with the KT150s.... right now I have no desire to do so the amp sounds so good.  I probably will try them some day... maybe in a few months.
Anywho... I hope this helps some folks. 

PeaceBruce in Philly

bruce_philly
soundermn's avatar
soundermn
344 posts
 
Bruce, I think you need to let the KT150s settle in for at least 100 hours.  I noticed that they change the most in the first 50, but will still settle in more for upwards of 200 hours.  I did that same thing you are... swapping things around.  I had EL34, KT120 and KT150s, as well as a variety of tubes in front.  Right now I have the KT150s and Ciftes.  The best thing I did was leave it all alone for a while, enjoy the sound, and let it settle in.  Now, it sounds fantastic, and I find that rolling the stock AU7s in, versus the Cifties, I like them both.  I have others like the 4003 as well, but I think the Cifties are pretty good overall.

Enjoy the music for a while, then roll tubes in 3 or 6 months.
bruce_philly OP
31 posts
 
Mullards NOS.
OK, so I am now done... seriously, I think I am done.....
I left the PL 12AU7s in ..... so the amp is stock except for the KT150 power tubes.... the KT150s appear to be stable... amp is stable... sounds wonderful.  Now I have the Mullards sitting here staring at me.  OK, in they go...... guess what... they sound really similar to the Chinese 12AU7s stock in the PL!   Honestly, the amp sounds great with either.  I am leaving the Mullards in..... there is just nothing wrong with this system now.  Nothing.  If the Mullards crap out, I will just put the original Prima Luna 12AU7s back in and be done with it.
Interesting journey.....  This Prima Luna integrated is one of my better buys.  If you consider it, I can't imagine you not being happy with one.

PeaceBruce in Philly
decooney
1,949 posts
 
bruce_philly OP28 posts08-03-2018 1:26pmMullards NOS.
OK, so I am now done... seriously, I think I am done.....
I left the PL 12AU7s in ..... so the amp is stock except for the KT150 power tubes.... the KT150s appear to be stable... amp is stable... sounds wonderful. Now I have the Mullards sitting here staring at me. OK, in they go...... guess what... they sound really similar to the Chinese 12AU7s stock in the PL! Honestly, the amp sounds great with either. I am leaving the Mullards in..... there is just nothing wrong with this system now. Nothing. If the Mullards crap out, I will just put the original Prima Luna 12AU7s back in and be done with it.
Interesting journey..... This Prima Luna integrated is one of my better buys. If you consider it, I can’t imagine you not being happy with one.

PeaceBruce in Philly


-------------------------------------

Similar conclusion exactly one year later today. Found similar tube combo results with a completely different preamp/amplifier. Same output and input tubes though. It has been a journey for me too with other amps using GL KT88s, Shuguang EL34s, TS KT120s, and now staying with Tung Sol KT150 output tubes paired with NOS Mullard input tube in combination for an interesting combination and result.

My mono amps run KT150s and utilize 12AU7 for input and 12AT7 for the driver tube. Not sure I’d ever go back to other output or input tubes once discovering this combo when deciding to stay with KT150s.

Next?
Will be interesting to see how long the KT150 lives like this before some other new high output tube comes along and moves it off the pedestal.

tablejockey
3,882 posts
 
As a long time owner of PL amps, always interested to read what others hear with different tubes.

Like everything audio, a particular tube doesn't always have the same end result in a particular system.

I have heard the KT150 many times. Nice, but 8@$100 each, it made me think twice about dropping that much cash on tubes.

The 6l6G has been in my HP for several  years. Not quite the EL34 mids, and more convincing bass. They have their own, unique sound that is pleasing to my ears.
It's a lower powered tube,  but I don't have any volume issues.

Also a cool vintage look, being a 60 year old tube. Unlike new tubes, they fire up like lightbulb.

As a bonus, you can still find them for a reasonable price. 

I hear the Brimar as a more relaxed tube for the gain position. The Cifte does seem to add more excitement in the highs. I prefer the Brimar,after listening with the Cifte for a few years.Speaker design probably has a factor in performance.
 
soundermn's avatar
soundermn
344 posts
 
@tablejockey 
I agree about the cost of the KT150s.  But, I do like them!  I would really like to hear the 6L6G, but don't want to buy any more tubes.  Maybe next year.  

Anyway, I wanted to share that I found a set of new KT150s on eBay for about $550 for the set.  They've been working perfectly for two years without a hitch.  So, options are out there... even if Uncle Kevin would say not to buy tubes on eBay.

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