Welcome, Guest. Please Login or Register
Decware Audio Forums
05/30/24 at 05:32:27 

Most recent 50 posts

Pages: 1
Send Topic Print
Replacing Output Tubes (Read 1031 times)
Verified Member

Music heals the soul

Posts: 28
Replacing Output Tubes
08/18/22 at 02:18:35
I just spent the last several hours replacing tubes one at a time to determine why I was losing 90 percent volume after 10-20 minutes of play time on my 1+ year old Torii MKIV.

The problem occurred on both left and right but at different times.  Each tube replacement still resulted in volume loss until I replaced the KT66 output tubes.  Problem solved.  Right channel..... Then left.

At least one tube on both channels failed within a couple of days of each other?  What are the odds?  Is this an indication of a problem with my power (not conditioned, straight from the wall) or other common component?  I would have replaced all 4 as a matched quad anyway, but seemed odd to have simultaneous failures.

I don't play super loud. Moderate listening time in the evenings.  Any insight would be appreciated.
Back to top

The Zen TORII MK4 // WiiM Pro Plus /w Tidal // Klipsch RP-600M
WWW   IP Logged
Seasoned Member

Posts: 202
Re: Replacing Output Tubes
Reply #1 - 08/21/22 at 22:36:34

I recommend writing to Steve directly, if you haven't already. He's the designer same creator of your amp, so will have the most comprehensive understand of your situation. He's generally very prompt with his responses.

Very sorry to hear about your experience. I had tube issues right out of the gate as well. Mine was likely due to tube damage during shipping. The good news is all will end well with Decware helping you, particularly with an amp under warranty. Good luck.
Back to top
  IP Logged
Tommy Freefall
Seasoned Member

Posts: 403
Re: Replacing Output Tubes
Reply #2 - 08/25/22 at 22:32:54
Over the course of about a year I experienced pretty much the same thing about 3 times with KT66 tubes. About every 4 months one or both of the channels would weaken or go silent.
I was convinced it was an amp issue.
I was on the verge of sending it back to Decware to diagnose.
As a last ditch effort, I decided to pop in a fresh set of EL34s instead of the usual KT66s.
That was about 10 months ago and the amp has run fine ever since without any issue.
I guess I was having bad luck - kept getting weak KT66s.

Back to top

Torii MkIV w/ 25th ann mods
Rachael SE34I.5
Benchmark AHB2
Zu Audio DWX Supreme
ZStage, ZRock2
Tascam CD-240
Border Patrol DAC
Benchmark DAC3 HGC
Bluesound Node
Zu Audio Mission speaker cables
Decware I/Cs
PI Audio MiniBUSS
Zenhead, Grado 325e, Z
  IP Logged
Pages: 1
Send Topic Print