solid state amp warm-up time, myth or fact? - diyAudio
Go Back   Home > Forums > Amplifiers > Solid State

Solid State Talk all about solid state amplification.

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 19th October 2003, 04:15 AM   #1
AJT is offline AJT  Philippines
diyAudio Moderator
 
AJT's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
Default solid state amp warm-up time, myth or fact?

there are some claims that amps can benefit from warm up time, please give your insights into this....thanks
  Reply With Quote
Old 19th October 2003, 06:43 AM   #2
AJT is offline AJT  Philippines
diyAudio Moderator
 
AJT's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
i read in one of the onkyo integra high power amps brochure, that warm- up time of at least 20 is suggested to get the sound right, what can you say about this? what is the engineering basis for this if there is,
  Reply With Quote
Old 19th October 2003, 07:01 AM   #3
diyAudio Member
 
li_gangyi's Avatar
 
Join Date: Jun 2003
Location: Woodlands Circle
Not sure...caps values and ESR shifts when it heats up???
__________________
Kids in the back seat cause accidents...Accidents in the back seat cause kids...
  Reply With Quote
Old 19th October 2003, 08:04 AM   #4
djk is offline djk
diyAudio Member
 
djk's Avatar
 
Join Date: Feb 2001
Location: USA
I once rebuilt a 200W Mark Levinson amplifier. Every transistor was replace in both channels. Every capacitor. The bias was identical. The amplifier warmed up faster on one channel than the other. One side sounded fine after 10 minutes, the other took about 20 minutes. The channels sounded identical after warmup.

After close examination it was found that one channel had a different brand of resistors for the 1/4W sized parts. Same 1% values, just a different brand.

Go figure.
  Reply With Quote
Old 19th October 2003, 08:48 AM   #5
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Yes, solid state amps take time to warm up... sometimes they get better over days -- one of the reasons i never bother turning my amps off.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 19th October 2003, 09:44 AM   #6
AJT is offline AJT  Philippines
diyAudio Moderator
 
AJT's Avatar
 
Join Date: May 2003
Location: Palatiw, Pasig City
Default so there really is a warm-up time?

and this is because of capacitors charging and transistors coming up to temp?
  Reply With Quote
Old 19th October 2003, 09:52 AM   #7
diyAudio Member
 
Join Date: Sep 2002
Location: Sweden
Quote:
Originally posted by djk
I once rebuilt a 200W Mark Levinson amplifier. Every transistor was replace in both channels. Every capacitor. The bias was identical. The amplifier warmed up faster on one channel than the other. One side sounded fine after 10 minutes, the other took about 20 minutes. The channels sounded identical after warmup.

After close examination it was found that one channel had a different brand of resistors for the 1/4W sized parts. Same 1% values, just a different brand.

Go figure.

Unfortunately manufacturers use different definitions for the
power ratings. One brand may be reasonably cool at the
rated power while another brand may be close to overheating.


As for the warm-up time, most transistors are likely to be
operating well within their margins, so they will probably
heat up slowly to the steady state operating temperature.
  Reply With Quote
Old 19th October 2003, 10:23 AM   #8
Electrons are yellow and more is better!
diyAudio Member
 
peranders's Avatar
 
Join Date: Apr 2002
Location: Göteborg, Sweden
Blog Entries: 4
Quote:
Originally posted by djk
The bias was identical.
You mean the setting or the bias current, the value? Apperently not (the value), because of the different heating up times.

My contribution to this thread is that I suspect that a "cool" amp is less sensitive compared to a "hot" one.

Leaving it on, I think a "hot" amp has nothing to gain if it's left on 24/7. It will probably break down much sooner compared to an amp which is switched on when it's actually used. Costs money also to have it on, except for houses with electrical heating.
__________________
/Per-Anders (my first name) or P-A as my friends call me
Tube Buffered Gainclone in work |Thread || Diamond buffer |Thread for the group buy | Wiki
  Reply With Quote
Old 19th October 2003, 10:28 AM   #9
diyAudio Member
 
li_gangyi's Avatar
 
Join Date: Jun 2003
Location: Woodlands Circle
So what actually causes the "better" sound?? Or izzit the sound that stays permantely after it heats up?? I haven got a problem with needing to heat up amps before... I mean SS ones...and I thought they didn't need serious heating up...
__________________
Kids in the back seat cause accidents...Accidents in the back seat cause kids...
  Reply With Quote
Old 19th October 2003, 12:23 PM   #10
diyAudio Member
 
ashok's Avatar
 
Join Date: Jun 2002
Location: 3RS
Default Turning it off and on.

Quote:
Leaving it on, I think a "hot" amp has nothing to gain if it's left on 24/7. It will probably break down much sooner compared to an amp which is switched on when it's actually used.
Actually turning it off and on many times is worse than leaving it on all the time. This is because turning it on is the most stressfull time for the components of the amp. Especially the power supply and power switches and relays.

Most research organisations leave their equipment on most of the time. On off periods are minimised. Apart from other reasons reliability is one reason to reduce on off cycles.

So leaving it on all the time is a good practice . Amps also take time to break in - may be months ! Leaving it on also stabilises the operating point. So when you want to listen, it is ready. The only negative thing about this is that in countries where the power fluctuation is very bad it might kill the amp if you get spikes or high voltage often. So you will have to do this judiciously.
People with power hungry amplifiers may be forced to turn them off due to their idle power consumption! That I guess probably covers most Class A users except Nelson's amps and similar types.
Cheers.
__________________
AM
  Reply With Quote

Reply


Hide 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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
TDA1541A - Double Crown - Myth or Fact - How to Test poynton Digital Line Level 9 18th June 2009 11:32 AM
Off topic: SAF........ fact or myth???? rabbitz Multi-Way 19 14th April 2004 10:24 PM
The Solid State Wiki - Your solid state reference guide Jason Solid State 0 25th June 2002 05:26 PM


New To Site? Need Help?

All times are GMT. The time now is 03:13 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2