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

Solid State Talk all about solid state amplification.

Power Amplifier Input Sensitivity
Power Amplifier Input Sensitivity
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 21st June 2018, 05:32 PM   #1
AlanF00 is offline AlanF00  United States
diyAudio Member
 
Join Date: Jun 2018
Location: Colorado
Default Power Amplifier Input Sensitivity

I haven't found any clear statements of audio industry standard input sensitivities for power amplifiers. My survey of various amps turns up various sensitivities, such as 1.35V rms for Douglas Self's gain-of-21 "Blameless power amplifier" (p. 311, "Audio Power Amplifier Design", 6th Ed.) which can produce 100W into 8 ohms.


Does the audio industry have any standards on input sensitivity for maximum power output?


Obviously, if there is one standard, then amplifier gain will depend on it. For example, Self's "Blameless" amplifier has a voltage gain of 21, whereas a 200W design would require a gain of nearly 30 for the 1.35V rms input.


I've found pre-amp output voltages up to 4V rms, which perhaps implies that power amp input sensitivities don't vary all that much from Self's 1.35V number.
  Reply With Quote
Old 21st June 2018, 11:45 PM   #2
THD+N is offline THD+N  United States
diyAudio Member
 
Join Date: Jul 2007
Location: Orlando, Florida
There is not an audio industry standard. Most amps fall between 1 or 2 volts RMS for input sensitivity. This is dictated by a few design choices, one being noise. High gain will increase noise, so you donít want to set the gain too high.
  Reply With Quote
Old 22nd June 2018, 10:22 PM   #3
AlanF00 is offline AlanF00  United States
diyAudio Member
 
Join Date: Jun 2018
Location: Colorado
Quote:
Originally Posted by THD+N View Post
There is not an audio industry standard. Most amps fall between 1 or 2 volts RMS for input sensitivity. This is dictated by a few design choices, one being noise. High gain will increase noise, so you donít want to set the gain too high.

Thank you.


What tradeoffs do people generally make beyond reducing noise?


I well understand the tradeoff between gain and stability, but assuming that good stability is achievable (i.e., stable loop gain), what other things do people worry about?
  Reply With Quote
Old 24th June 2018, 11:36 AM   #4
nigelwright7557 is offline nigelwright7557  United Kingdom
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
The usual standard is 0db, around 1 volt RMS.
__________________
PCBCAD51 pcb design software. 2018 version out now with lower prices >> http://www.murtonpikesystems.co.uk
  Reply With Quote
Old 25th June 2018, 01:07 AM   #5
Burnedfingers is offline Burnedfingers  United States
diyAudio Member
 
Join Date: Nov 2002
Commercial designs can be .7 or even .5 for full output.

Common input levels to obtain full power in "home" equipment generally is anywhere from 1 volt as stated to some amps I've seen that require 2.50 for full output.
  Reply With Quote
Old 25th June 2018, 05:49 PM   #6
bogdan_borko is offline bogdan_borko  Serbia
diyAudio Member
 
bogdan_borko's Avatar
 
Join Date: Nov 2005
Location: serbia, zajecar
Quote:
Originally Posted by nigelwright7557 View Post
The usual standard is 0db, around 1 volt RMS.
Yes, but long time ago, before cd players... now it's all over the place, 0.5 to 2 or more volts.
__________________
Svakog dana u svakom pogledu sve manje nazadujem.
  Reply With Quote
Old 25th June 2018, 05:55 PM   #7
nigelwright7557 is offline nigelwright7557  United Kingdom
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
Quote:
Originally Posted by bogdan_borko View Post
Yes, but long time ago, before cd players... now it's all over the place, 0.5 to 2 or more volts.
That's why audio mixers go into the red at 0db.
Its an industry standard.
__________________
PCBCAD51 pcb design software. 2018 version out now with lower prices >> http://www.murtonpikesystems.co.uk
  Reply With Quote
Old 28th June 2018, 07:17 PM   #8
east electronics is offline east electronics  Greece
diyAudio Member
 
east electronics's Avatar
 
Join Date: Jan 2006
Location: Athens GREECE
Most preamps of the past or near past amplify between X10 or X20 for now days sources a good balance between juice and noise will be X6
__________________
SERVICE ΕΝΙΣΧΥΤΩΝ ΚΑΙ ΙΑΠΩΝΙΚΩΝ ΜΗΧΑΝΗΜΑΤΩΝ ΗΧΟΥ www.eastelectronics.gr
  Reply With Quote
Old 28th June 2018, 08:07 PM   #9
nigelwright7557 is offline nigelwright7557  United Kingdom
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
Quote:
Originally Posted by east electronics View Post
Most preamps of the past or near past amplify between X10 or X20 for now days sources a good balance between juice and noise will be X6
I use x5 in my mixer designs for amplifying line level.

For stage use its good to have the mixer show red at 0db or some expensive speakers are going to get fried.
__________________
PCBCAD51 pcb design software. 2018 version out now with lower prices >> http://www.murtonpikesystems.co.uk
  Reply With Quote
Old 28th June 2018, 08:09 PM   #10
CharlieLaub is offline CharlieLaub  United States
diyAudio Member
 
Join Date: Mar 2007
Location: California
Quote:
Originally Posted by AlanF00 View Post
I haven't found any clear statements of audio industry standard input sensitivities for power amplifiers. My survey of various amps turns up various sensitivities, such as 1.35V rms for Douglas Self's gain-of-21 "Blameless power amplifier" (p. 311, "Audio Power Amplifier Design", 6th Ed.) which can produce 100W into 8 ohms.


Does the audio industry have any standards on input sensitivity for maximum power output?


Obviously, if there is one standard, then amplifier gain will depend on it. For example, Self's "Blameless" amplifier has a voltage gain of 21, whereas a 200W design would require a gain of nearly 30 for the 1.35V rms input.


I've found pre-amp output voltages up to 4V rms, which perhaps implies that power amp input sensitivities don't vary all that much from Self's 1.35V number.
I believe that either 0.707Vrms or 1Vrms is the consumer "standard". The problem is that manufacturers do not really hold to it. I have an Adcom amp from the 1990s with an input sensitivity of 1.75Vrms when in bridge mode.

With an analog preamp this was (in the past) never really a problem because most of them could put out 5Vrms or so. These days I have DAC outputs connected directly to amplifiers and I discovered that some of these only have 1Vrms output capability! I now make sure to choose my DAC a little more carefully in terms of its max Vout,rms.

If you reduce the gain of the amplifier and then require a higher voltage to reach the same output power you have also reduced the noise gain. My guess is that this explains upward creep in the input sensitivity.
__________________
Visit my Audio Web Page <<--CLICK TO LEARN MORE-->> Get my LADSPA plugins
  Reply With Quote

Reply


Power Amplifier Input SensitivityHide 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
Advice on instrumentation needed to measure Ampís Input Sensitivity and Power Output. dannoto Equipment & Tools 5 28th October 2016 10:11 PM
Amplifier sensitivity for RCA and XLR input Macleod Solid State 20 17th March 2010 01:43 PM
How to raise input sensitivity on power amp? jazzpeter65 Solid State 5 15th December 2003 11:59 AM
Son Of Zen Input Sensitivity rutcho Pass Labs 3 30th November 2003 03:46 PM
Power Amplifier Sensitivity EternaLightWith Tubes / Valves 13 3rd January 2003 11:49 AM


New To Site? Need Help?

All times are GMT. The time now is 05:52 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki