Gain evaluation of a preampli stage - 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 4th February 2009, 12:29 PM   #1
diyAudio Member
 
Join Date: Nov 2008
Default Gain evaluation of a preampli stage

Please, can somebody help me to evaluate the gain of the preamplifier stage figured in the attached image?
If yes, how?
Thank you very much.
Attached Images
File Type: jpg image.jpg (84.6 KB, 153 views)
  Reply With Quote
Old 4th February 2009, 02:42 PM   #2
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
Looks like some RIAA Phono.
Which means that the gain is different at different freq.
What the gain is at 1 kHz, nominal, I can not say.

Shuold be possible to run in spice simulator, to find out.
And get the AC Analysis frequency/gain curve.
__________________
lineup
  Reply With Quote
Old 4th February 2009, 03:10 PM   #3
diyAudio Member
 
Join Date: Nov 2008
Oh, this is certainly a line preamplifier stage, in fact this stage follows the volume control in a Marantz PM78 integrated amplifier. This means that is a strictly flat preamplifier.
Thanks however.
  Reply With Quote
Old 4th February 2009, 03:54 PM   #4
diyAudio Member
 
Andypairo's Avatar
 
Join Date: Sep 2002
Location: near Milano , Italy
At a quick glance the AC gain seems to depend mostly on the ratio between the 2k2 resistor and the series of 270Ohm+1K trimmer, so it can be adjusted in from slightly less than 2 to slightly less than 10.

Ciao

Andrea
__________________
I don't believe in audiophile components - except when I can get them at frugal-phile(tm) prices
  Reply With Quote
Old 4th February 2009, 03:59 PM   #5
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
Ok.
Gain between 2 an 10 for line amplifier makes sense.
Adjustable with the pot.
__________________
lineup
  Reply With Quote
Old 4th February 2009, 04:00 PM   #6
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Sofia
Quote:
Originally posted by lineup
What the gain is at 1 kHz, nominal, I can not say.

Shuold be possible to run in spice simulator, to find out.

Goodness gracious. Another spice junkie?
  Reply With Quote
Old 4th February 2009, 04:01 PM   #7
lineup is offline lineup  Sweden
diyAudio Member
 
lineup's Avatar
 
Join Date: Dec 2005
Location: the north
Don't you have Spice, analog_sa
Where have you been last 10 years
__________________
lineup
  Reply With Quote
Old 4th February 2009, 06:55 PM   #8
mjf is offline mjf  Austria
diyAudio Member
 
Join Date: Jan 2009
Location: Austria
hello.
quick estimated: (2.2div0.27)+1=8 high gain
and (2.2:1.27)+1=1.7 x lowest gain...
greetings...........
  Reply With Quote
Old 4th February 2009, 08:28 PM   #9
diyAudio Member
 
Join Date: Nov 2008
That's all, thank you very much!
  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
Gain stage with g2-feedback. jane Tubes / Valves 25 3rd July 2013 09:21 PM
New gain stage .. Opinions??? nitrate Tubes / Valves 4 26th January 2009 01:02 PM
Simple 12v gain stage dublin78 Solid State 10 14th April 2008 03:37 PM
Output stage with gain rtarbell Solid State 18 27th October 2006 07:15 PM
Heretical Unity Gain line stage PLUS a little gain ? yagas Tubes / Valves 7 24th January 2006 01:30 PM


New To Site? Need Help?

All times are GMT. The time now is 06:03 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