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

The Lounge A place to talk about almost anything but politics and religion.

Breaking / Burning In Tubes - A New Thought
Breaking / Burning In Tubes - A New Thought
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 9th February 2019, 01:34 PM   #1
jomac is offline jomac
diyAudio Member
 
Join Date: Dec 2018
Default Breaking / Burning In Tubes - A New Thought

I have recently purchased a tube amplifier for home stereo listening, and even though I have MUCH experience with guitar tube amplifiers, I wanted to throw something out there for consideration as it relates to breaking in tubes....

I read everywhere about the length of burn-in time required for pre and power tubes, and there seems to be quite a difference between tubes and various manufacturers. Some people state that they have to burn in their tubes for 10 hours before they "settle down" or some other descriptive word or phrase, while others state 100 or more hours being required. This is a real head-scratcher for me because most tubes are essentially using the same materials in their construction. I understand that the mass and surface area of the plates and getters may be different, but I don't think that this would explain the time required to burn in a tube. Sooo....

I have a theory, and I may not be alone in this or even be the first to posit such an idea. I believe that breaking in tubes has more to do with the number of heat cycles the tubes undergo rather than the length of time they are played. The most physical stress that a tube encounters is when it is warming up or cooling down. When a tube is up to temp and doing it's thing, the only thing that is going on is a transfer of electrons. The path that the electrons are taking isn't creating any type of break-in, or is it?

To test this theory, I have a 12AX7 / 12AU7 pre section in my amp. I played music through the amp for many days before the sound "settled in" and I could start to hear that warm rich bass and mid-range. As is common, I wanted an even better silky mid-range and richer bass, so I rolled some new production Mullards into 12AX7 sockets, and nos Brimars into 12AU7 sockets. Instead of going back through 100+ hours of break-in time, I did the following. In addition to my regular listening of 1 to 2 hours per night, I also power cycled my amp with no-load 4 to 6 times per day - - fully heating the tubes each time (approx :15 to :30 minute cycles). I was astonished after 3 or 4 days of doing this (maybe 20 cycles total) at how rich and warm the bass and mid-range became. And, let me tell you that the nos Brimar CV4003's had an over-the-top amount of air in the mid-range when I first heard them and the bass was not very well articulated and controlled, but now they are just WOW!

Literally, within 4 or 5 short listening sessions over the course of a week, plus 15 to 20 power cycles through full heating and cooling, the tubes are producing such a sweet amount of tonality and richness. Here, a month later and 100+ hours of listening, the sound has not changed at all. Maybe it has improved further, but I haven't noticed any other significant changes in sound.

So, what are some additional thoughts on this theory?
  Reply With Quote
Old 9th February 2019, 04:43 PM   #2
Palustris is offline Palustris  United States
diyAudio Member
 
Palustris's Avatar
 
Join Date: Aug 2006
Location: Cape Cod
"Here, a month later and 100+ hours of listening, the sound has not changed at all."

That's an amazing achievement! After 100 hours you are still able to remember exactly how the "tubes" sounded that very first hour.
  Reply With Quote
Old 9th February 2019, 04:49 PM   #3
jan.didden is offline jan.didden  Europe
diyAudio Member
 
jan.didden's Avatar
 
Join Date: May 2002
Location: Westende Resort, BE coast
Quote:
Originally Posted by jomac View Post

So, what are some additional thoughts on this theory?
Have you considered the possibility that it is you that is breaking in? You are much more malleable than a tube.

Jan
__________________
Cable: a potential source of trouble interconnecting two other potential sources of trouble - Erik Margan
Linear Audio pubs and articles . The SilentSwitcher now at diyaudio store SilentSwitcher. Keeping in touch with SY.
  Reply With Quote
Old 9th February 2019, 04:50 PM   #4
kodabmx is offline kodabmx  Canada
diyAudio Member
 
Join Date: Oct 2011
Location: Toronto
I'm just going to wait and see what/if DF96 has something to say about this...
  Reply With Quote
Old 9th February 2019, 04:50 PM   #5
JonSnell Electronic is offline JonSnell Electronic  United Kingdom
diyAudio Member
 
JonSnell Electronic's Avatar
 
Join Date: Dec 2012
Location: The Jurassic Coast, England. GB
Someone has an over zealous imagination caused by the 'expensive component syndrome'.
__________________
Support for Fender, Marshall and all Valve Equipment; Audio Innovations, Audiorama FU29, Quad and Leak. www.jonsnell.co.uk
  Reply With Quote
Old 9th February 2019, 05:26 PM   #6
jazbo8 is offline jazbo8
diyAudio Moderator
 
jazbo8's Avatar
 
Join Date: Jan 2011
Location: In Transient
Breaking / Burning In Tubes - A New Thought
Moved to the Lounge.
  Reply With Quote
Old 9th February 2019, 05:44 PM   #7
Galu is online now Galu  Scotland
diyAudio Member
 
Join Date: Apr 2018
Quote:
Originally Posted by jomac View Post
I believe that breaking in tubes has more to do with the number of heat cycles the tubes undergo rather than the length of time they are played. The most physical stress that a tube encounters is when it is warming up or cooling down.
The accumulated stress due to the expansion and contraction of the electrodes may affect the life of the valve, but I'm not aware of any mechanism by which 'power cycling' the valves in the way you suggest would influence the sound of the amplifier.
  Reply With Quote
Old 9th February 2019, 06:00 PM   #8
dhaen is offline dhaen  Europe
diyAudio Moderator Emeritus
 
dhaen's Avatar
 
Join Date: Jun 2002
Location: U.K.
I'm normally a sceptic about these things but don't some valves such as the 6C33 when used in OTL "settle down" their DC conditions after a bit of use?

In line with Jan's theory, I believe I'm far more malleable than any circuit:
I have an open plan house, so I fitted ceiling speakers in a couple of rooms for sound "reinforcement". When new, I was disappointed by the sound, but now I find it quite acceptable. I'm sure it was my malleability rather than a change in sound of the class D amps, or the mass produced ceiling speakers.
  Reply With Quote
Old 9th February 2019, 06:15 PM   #9
Galu is online now Galu  Scotland
diyAudio Member
 
Join Date: Apr 2018
Quote:
Originally Posted by dhaen View Post
I'm normally a sceptic about these things but don't some valves such as the 6C33 when used in OTL "settle down" their DC conditions after a bit of use?
That may well be the case, but jomac's theory is that switching new valves on, then off, six times a day for a period of 15 minutes each time, over 4 days will improve their sound.

The question is, how well does this stand up as a theory and can it be substantiated by experiment?
  Reply With Quote
Old 9th February 2019, 07:10 PM   #10
schiirrn is online now schiirrn  Germany
diyAudio Member
 
Join Date: Nov 2018
New tubes need a few hours (3-5) for emission to stabilise. If you measure current draw you will see it goes up. This means that the operating point changes. If the amp is designed badly enough that change will be audible.
  Reply With Quote

Reply


Breaking / Burning In Tubes - A New ThoughtHide 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
Breaking in tubes wanders The Lounge 13 4th February 2017 07:30 PM
breaking in amp and Tubes, TSE. Guarnera Tubelab 3 21st April 2016 04:53 AM
The Burning Amp Festival-Burning Gadgets Preview Zen Mod Everything Else 116 25th June 2015 07:38 AM
Breaking in your tubes? Lingwendil Tubes / Valves 3 6th June 2009 05:48 AM
whats a good time for breaking in tubes karma Tubes / Valves 2 14th May 2003 07:51 PM


New To Site? Need Help?

All times are GMT. The time now is 05:00 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki