Question about Discrete Based(Transistor) Amps? - 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 31st August 2003, 04:14 PM   #1
diyAudio Member
 
Join Date: Sep 2002
Location: USA
Default Question about Discrete Based(Transistor) Amps?

I would like to know if Amplifiers based on a Discrete Transistor design need a "break in" period before they actually start to sound good, open up, or is this just a "myth". Especially Class A designs.
  Reply With Quote
Old 31st August 2003, 04:19 PM   #2
diyAudio Member
 
Jan Dupont's Avatar
 
Join Date: Apr 2003
Location: Copenhagen, Denmark
Send a message via MSN to Jan Dupont
With that question your are almost sure of dividing the diyaudio users into two groups
I like to make a burn-in test, mostly to assure that the amps are working proberly.... If it has any effect on the sound I can't tell you... I never notised any difference
__________________
Free Schematic and Service Manual downloads www.audio-circuit.dk, Company: www.dupont-audio.com, Joint venture: www.DupontMantra.com
  Reply With Quote
Old 31st August 2003, 04:51 PM   #3
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
TomD

Break-in has little to do with amp type or class. A lot of the subjective effect is due to passive components, mostly capacitors, but diodes and transistors are also known to break-in. Some listeners are more sensitive to the effect than others. While i certainly notice changes in the sound of wires and caps, if a component sounds really bad in the first place no amount of break-in will ever make it amazingly good. Yes, i've read opinions to the contrary but tend to take them with more than a pinch
  Reply With Quote
Old 31st August 2003, 06:26 PM   #4
diyAudio Moderator Emeritus
 
jean-paul's Avatar
 
Join Date: Sep 2002
Location: Germany
Quote:
Yes, i've read opinions to the contrary but tend to take them with more than a pinch
Black Gate anyone ?
__________________
It's only audio. Official member of the Norske Brillegeit Gang.
  Reply With Quote
Old 31st August 2003, 07:36 PM   #5
diyAudio Member
 
Join Date: Aug 2003
Location: Swampscott MA
Default Amp Break In

The only "break in" I have noticed to date has been the large electrolytic caps in the power supply. When they are first turned on the ripple and noise are a bit high but they come down to normal level a day or so later.
The break in that most audiophiles talk about as far as I can tell is just time getting used to a new piece of equipment. Seems like more physcology than anything else. Most well designed equipment out there has more in common than most would care to believe.
d.b.
__________________
I was an audiophile until I found out what they were doing in the recording studio.
  Reply With Quote
Old 31st August 2003, 08:27 PM   #6
sam9 is offline sam9  United States
diyAudio Member
 
sam9's Avatar
 
Join Date: Jun 2002
Location: Left Coast
This may get me cat calls, but I think it's the owner/listener that "breaks in". In my case it's actually the opposite -- when something I've newly built is first listened to (provided there isn't something drasticly wrong with it) I'm so amazed and astounded that it works that I'm convinced it's the best amp of all time. After a few weeks it starts to sound more ordinary. :
  Reply With Quote
Old 31st August 2003, 08:50 PM   #7
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
Guys, you may think that experienced listeners actually go through the pain of adjusting to the sound of new equipment but let me assure you that's seldom the case. New equipment gets burnt in either by Fm interstation noise, pink noise, square waves, repeat CD or 'proper' burn-in generator. I always do one of the above with cables and thus my ears do not adjust. Yes, the sound of practically every bit of audio kit changes but the differences are seldom dramatic.
  Reply With Quote
Old 1st September 2003, 03:24 PM   #8
diyAudio Member
 
Join Date: Apr 2003
Location: Cambridge, UK
Whenever I've built a new amp I leave it switched on and connected to a dummy load for a day or so, just to check that it's thermally (& electrically) stable. I wouldn't risk my best speakers on a brand-new circuit, so I couldn't tell you what it sounds like without 'running in'.

Electrolytic caps use the applied DC bias to chemically regenerate the dielectric layer, so it's plausible that their characteristics change within a short time of power first being applied. I'm never heard of anything analogous for, say, transistors or resistors, although if you run any component at or beyond its maximum working temperature (e.g. a class-A amp with insufficient heatsinking) all sorts of parameters will start to drift.

Cheers
IH

PS. Ears undoubtedly adjust to accomodate different tonal balance over time. Put your TV sound through proper speakers for a week, then try going back to the TV's own. It never sounded this bad before...
  Reply With Quote
Old 1st September 2003, 03:48 PM   #9
JoeBob is offline JoeBob  Canada
diyAudio Member
 
JoeBob's Avatar
 
Join Date: Nov 2001
Location: Montreal, Canada
I'll second the TV sound, we get used to sounds that we hear, only after we've heard better do they sound bad.

Human hearing is really complicated and there are always ongoing debates on weather we can hear a difference in passive parts of even wires, burn in should be grouped with those, a phenomena that is not understood...
  Reply With Quote
Old 1st September 2003, 04:57 PM   #10
DrG is offline DrG  South Africa
diyAudio Member
 
Join Date: Aug 2003
Location: South Africa
In my experience most equipment sounds a little stark until operating temperature/thermal equilibrium has been reached. To me this is most noticable in class A amps and tube stages.

By extension, the initial break-in period should be longer. Like a car. Most still have a run-in period and all must reach operating temp before given a little stick...
  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
Opamp based Amps - Question lshtram Solid State 3 6th January 2008 12:32 AM
THAT transistor headphone amp (250ma discrete opamp) design sanity check. Russ White Headphone Systems 19 13th December 2007 12:52 PM
Op amp based preamp with discrete output hags Solid State 11 17th September 2007 09:24 AM
Need help with discrete op amps. cadaverdog Pass Labs 6 17th September 2006 10:03 PM
Discrete amp based on LM38-- family internals? tiltedhalo Solid State 1 16th November 2005 01:06 AM


New To Site? Need Help?

All times are GMT. The time now is 05:15 AM.


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