2. amps-preamps
  3. 181044-132571

KT 150 failure

I bought a set of 150’s early this year for my Primaluna Dialogue Premium.  I’ve always run Gold Lion KT 66’s with no problems. Last week, during silence between songs, I heard this soft fluttering sound thru the woofer.  Cornwall’s.  The slightest tapping of the floor in front of the speaker produced the sound.  I went to the amp which is @6 feet away, and all looked fine- no red tube fail lights.  But the lightest touch to the far left tube really made the woofer flutter.  No red plate, static or popping.  After cool down and restart, tube is quiet until it warms up, then same situation.  Pulled them all and replaced with KT66’s.  All good now.  But I have a geeky question.  What happened with that tube?  In Dynaco Days, I had more dramatic failures.  It’s a fail, but what failed?  Thanks in advance for satisfying my curiosity.  

george53
jerryg123's avatar
jerryg123
3,429 posts
 

I have had great performance from my KT150’s and 170’s all purchased prior to the issues in Russia. Be mindful that all these Russian Tube Factories are US owned. How old are these 150’s? Meaning when did you buy them?

george53 OP
35 posts
 

I bought these in March from an outlet in Canada.  About the time that tubes were getting scarce.  I really just wanted some new 66’s or maybe to try some kt88’s.  All I could locate at that time were the 150’s.  Gave me a good excuse to move farther up the chain.  Long break in, but they sounded just great.  I’m hoping that this is a one off.  4 x expensive is a commitment I guess.  If it happens again too soon I’ll cut my losses and retube with 66’s maybe.  No whining from my end.  All this improves the quality of my life, every single day

tablejockey
3,805 posts
 

A microphonic or futzy  tube is part of tube ownership.

I've been pretty fortunate with my PL't tube consumption. NOS  US power tubes held up with 6 years of heavy use and had 2 PL branded Chinese EL34's go after couple years of moderate use.

I don't have any desire to try the KT 150 based on user  tube life reports, and price vs. expected tube life. PL HP user-8x power tubes of something over $50+ makes me think twice about what to try.

george53 OP
35 posts
 

Yup. Almost went with HP, but being retired, the cost of 8 tubes steered me to the Dialogue Premium.  Happy Happy.  This amp is on, a good portion of every day.  Tubes are the “cost of doing business”

tablejockey
3,805 posts
 

" Almost went with HP, but being retired, the cost of 8 tubes steered me to the Dialogue Premium"

I'm rounding 3rd base towards retiring. PL seems to fit retirement lifestyle-just turn it on and enjoy. 

Excellent "base" to use better than average sources/speakers. 

Happy listening during your retirement years.

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