Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Burned out power tube
Burned out power tube
Burned out power tube Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 24th January 2008, 08:44 AM   #1
fauxpas is offline fauxpas  Australia
diyAudio Member
 
fauxpas's Avatar
 
Join Date: Nov 2007
Default Burned out power tube

I have replaced the chinese 6P3P tubes with 6L6GC tubes of various designs. I recently picked up some 6P3S-E reflektor tubes and they sounded great for all of an hour before one burned out. Interestingly, it was the one of four that was from a different batch as it had slightly different markings. The reflektor logo was bigger etc.

Is it likely just a dodgy tube? Or are there enough differences between the 6P3P and 6P3S-E to not use the 6P3S-E again?

They were these common ebay tubes.

An externally hosted image should be here but it no longer works. Please upload images instead of linking to them to prevent this.
  Reply With Quote
Old 24th January 2008, 09:37 AM   #2
Colt45 is offline Colt45  Serbia
diyAudio Member
 
Join Date: Feb 2002
Location: Canada
Send a message via ICQ to Colt45
I'm not sure what your amp is running at, but don't run these at 'GC ratings. 20w.. 25w tops... watch Ug2...
  Reply With Quote
Old 24th January 2008, 12:18 PM   #3
woodturner-fran is offline woodturner-fran  Ireland
diyAudio Member
 
Join Date: Jan 2006
Location: Ireland
Funny that. Same thing happened me last night with an EL84. I was the far side of the room. Amp was on, bias was stable and voltage to the screen was spot on. Heard a crackle through the speakers and it had burnt before I could get back to the power switch. When I took the tube out there was a crack in the base of the tube. Whether that caused the problem, or was caused by the problem I couldn't guarantee but they had been working OK up to that. These tubes have been physically roughed a good bit, in and out loads of times etc.

Tube glowed bright, almost white (amp upside down and could see the glow through the centre of the socket) Burnt a screen stopper as well.


Never had it happen to me before, so it was a bit of a shock!


Fran
  Reply With Quote
Old 24th January 2008, 05:17 PM   #4
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Burned out power tube
Quote:
Originally posted by woodturner-fran
Funny that. Same thing happened me last night with an EL84. I was the far side of the room. Amp was on, bias was stable and voltage to the screen was spot on. Heard a crackle through the speakers and it had burnt before I could get back to the power switch. When I took the tube out there was a crack in the base of the tube. Whether that caused the problem, or was caused by the problem I couldn't guarantee but they had been working OK up to that. These tubes have been physically roughed a good bit, in and out loads of times etc.

Tube glowed bright, almost white (amp upside down and could see the glow through the centre of the socket) Burnt a screen stopper as well.


Never had it happen to me before, so it was a bit of a shock!


Fran
I've had that experience a few times with EI KT90's and JJ KT88, at 500V and above the experience is quite spectacular - and quite unwanted..

In the case of KT90 which developed internal shorts internal components vaporized instantly resulting in a fractured envelope - and in one case the envelope actually exploded, both the screen and cathode feedback resistors simultaneously burst into flame. A cap bank equivalent to 1000uF charged to 525V packs quite a wallop, hehe..
__________________
"To argue with a person who has renounced the use of reason is like administering medicine to the dead." - Thomas Paine
  Reply With Quote
Old 24th January 2008, 06:34 PM   #5
tubewade is offline tubewade  United States
diyAudio Member
 
tubewade's Avatar
 
Join Date: Jun 2007
I would say that it was not due to the fact that the valve was an "E" version, but rather that it was simply bad from the beginning. If it worked fine with chinese valves to start with it should work fine with these, providing, of course, that they aren't defective.

Wade
  Reply With Quote
Old 25th January 2008, 04:29 AM   #6
TubeHead Johnny is offline TubeHead Johnny  United States
diyAudio Member
 
TubeHead Johnny's Avatar
 
Join Date: Jan 2005
Location: The emerald city, Seattle, WA.
They look like like the same tubes that Sovtek uses for their 5881/6L6WGC. They're mediocre quality, even though many guitar amp manufacturers use them. I have used Sovtek 5881 tubes in one of my hi fi amps, but was never quite happy with the sound. If you received these tubes at a super low price, I'm sure they weren't completely tested and "weeded out" before they left the plant. Your best bet would be to run everything through a tester before putting them in your amp. (But that won't cover everything, like catastrophic failures).
  Reply With Quote
Old 25th January 2008, 03:26 PM   #7
richwalters is offline richwalters
diyAudio Member
 
richwalters's Avatar
 
Join Date: Sep 2003
Location: Schwartzwald
Perhaps with so much rebranding going on with the Russian tube market, this is the right time for someone knowledgable to give us an update where which tube version is made by whom ? It is confusing.

Personally, I've always avoided the Sovtek brand (the logo with the pigeon) as I find them notoriously inconsistent. That is both signal and power types.



richj
  Reply With Quote
Old 26th January 2008, 03:12 AM   #8
fauxpas is offline fauxpas  Australia
diyAudio Member
 
fauxpas's Avatar
 
Join Date: Nov 2007
I have been obsessed with sourcing generic russian tubes lately.

Primarily reflektor and voskhod tubes.

Net sources indicate to me that the reflektor plant in Saratov manufactures svetlana tubes, or did.

Before the tube popped, I must say I was impressed and am sourcing more from a different person. I found the reflektor and voskhod pre amp tubes very nice too in 6N1P and 6N23P guise...

So far, I have auditioned 1 x chinese, 2 x USA and 1 x russian 6L6 variants in my amp, and the 6P3S-E russian tubes easily sounded the best. They sounded the fullest, while others had incredible clarity at the top, the 6P3S-E felt great through the entire frequency range.

REFLEKTOR-SARATOV
Click the image to open in full size.

VOSKHOD-KALUGA
Click the image to open in full size.
  Reply With Quote
Old 26th January 2008, 03:16 AM   #9
tubewade is offline tubewade  United States
diyAudio Member
 
tubewade's Avatar
 
Join Date: Jun 2007
I wouldn't define myself as highly knowledgeable, but I have used a few Russian valves so I can relate my experiences in case they are helpful.

My first set were sold as Sovtek 6L6GC, but they are actually 6p3s. They are still in service. They sound OK but are not able to handle high voltage or great dissipation. Treat them as a 6L6GA and they will last. I'm using them in in an old amp that called for 6L6G.

I've also used several set of Sovtek 6L6WXT+ and not had any problems. I've had them in my Heath W5s for a long time and they function perfectly. They will replace 6L6GCs, 7581s, 7027As and KT66s in everything I've tried them in.

I've purchased several lots of OTK 6n14n and 6n14n-eb to match some quad sets for my own use and have found these to be excellent quality. They are heavier than their NOS counterparts. Out of probably 60 or so that I have purchased only two have tested less than perfect on the tester and even these work perfectly in an amplifier. No failures. No problems.

My experiences may be atypical from what I've read but I have been satisfied with the Russian valves I've used. I believe all of these were manufactured by Reflektor.
  Reply With Quote
Old 26th January 2008, 08:20 AM   #10
richwalters is offline richwalters
diyAudio Member
 
richwalters's Avatar
 
Join Date: Sep 2003
Location: Schwartzwald
Regarding brands and tube longevity, this 1950's KenRad version of 5U4G is by far my longest service tube in current use and has outstripped 45,000 hrs service mark and still with good emission.

Where did the Ken Rad brand originate from ? Did it have
it's origins in Canada ??

richj
Attached Images
File Type: jpg 5u4g.jpg (52.7 KB, 465 views)
  Reply With Quote

Reply


Burned out power tubeHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Burned Up Transformer in HiFi 6p3p Tube Amplifier dmitch31 Tubes / Valves 3 26th February 2009 04:40 AM
HELP Aleph 5 is burned? zigo3 Pass Labs 5 20th February 2008 01:00 PM
Burned T-amp fixable? jaste Class D 1 8th November 2007 09:38 PM
burned JLH fuse by connecting to Tube preamp rchung Solid State 3 28th September 2004 10:51 PM
I burned my Aleph 3! Please help! Jesse Pass Labs 25 26th October 2003 02:56 PM


New To Site? Need Help?

All times are GMT. The time now is 09:29 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio
Wiki