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
tablejockey
3,771 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
3,771 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.

jerryg123's avatar
jerryg123
3,429 posts
 

We’ll my rig only has 4 power tubes and have a load of 88s 120s 150s and 170s. Started buying when tensions were building in Russia. Had some insider info with a couple of joint ventures we were doing in Russia and Ukraine. Also when all the Russian scientist and engineers bailed from NASA in Houston. 

george53 OP
35 posts
 

Jerry, off topic, but always like to ask folks what differences they heard between those tubes.  Accepting different amps, rooms etc.  I still like to hear people’s opinions.  I always suspect that differences are there but not earthshaking.  In the same equipment.  If these 150’s don’t work out down the line,,,,I have other observations to mull over.  Thanks 

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