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.

Meridian 103 clone
Meridian 103 clone
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 17th March 2017, 11:52 AM   #11
analog_sa is offline analog_sa  Europe
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Cascais
Meridian 103 clone
Hi Bob. Not too sure about the resistor values you have changed at the input stage.

From what i understand, this being an inverting nfb amp, places the input pair bases at virtual ground. Looking at the original circuit the input impedance is then 11k and there is a T-network in the feedback loop, only the value of the resistor in series with C1 is not shown. Your modified values do raise the closed loop gain but also reduce the input impedance excessively.
  Reply With Quote
Old 17th March 2017, 12:42 PM   #12
RCruz is offline RCruz  Switzerland
nhinstruments
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Meridian 103 clone
Thank you for your precious input.

I now increased input impedance and modified feedback resistors accordingly.

Gain is now a suitable 26dB... Now must do some stability sims and square wave behaviour.
Attached Files
File Type: asc Meridian 103 exicon power amp EVO7.asc (11.7 KB, 30 views)
__________________
RC
  Reply With Quote
Old 17th March 2017, 12:45 PM   #13
RCruz is offline RCruz  Switzerland
nhinstruments
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Meridian 103 clone
BTW

My name is Ricardo

The post 10 was taken from another thread and it belongs to Bob Cordell... I posted it here to justify my doubts about this being or not a CFA
__________________
RC
  Reply With Quote
Old 17th March 2017, 01:19 PM   #14
RCruz is offline RCruz  Switzerland
nhinstruments
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Meridian 103 clone
Something is wrong... I seem to have 0dB OLG
Attached Files
File Type: asc Meridian 103 exicon power amp EVO7 TIAN.asc (13.3 KB, 21 views)
__________________
RC
  Reply With Quote
Old 17th March 2017, 05:35 PM   #15
analog_sa is offline analog_sa  Europe
diyAudio Member
 
analog_sa's Avatar
 
Join Date: Aug 2002
Location: Cascais
Meridian 103 clone
Quote:
Originally Posted by RCruz View Post
BTW

My name is Ricardo

I knew that. Silly me
  Reply With Quote
Old 18th March 2017, 09:48 AM   #16
AndrewT is offline AndrewT  Scotland
R.I.P.
 
Join Date: Jul 2004
Location: Scottish Borders
Quote:
Originally Posted by RCruz View Post
............. got stuck with too low gain......
Open loop gain, or closed loop gain?
__________________
regards Andrew T.
  Reply With Quote
Old 18th March 2017, 11:59 AM   #17
RCruz is offline RCruz  Switzerland
nhinstruments
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Meridian 103 clone
Hello andrew
Did some work this morning so now i have 26db closed loop.
Will post a sch latter hoping you would comment on it
__________________
RC
  Reply With Quote
Old 20th March 2017, 07:04 PM   #18
RCruz is offline RCruz  Switzerland
nhinstruments
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Meridian 103 clone
Today I managed some free time for this.

I believe I am getting good results now...
Attached Images
File Type: png FFT 1KHz 1Vac.PNG (48.8 KB, 187 views)
File Type: png I square bases Q3 Q4.PNG (41.4 KB, 185 views)
File Type: png Phase margin 97 378Khz.PNG (84.5 KB, 183 views)
File Type: png SCH EVO8.PNG (58.1 KB, 190 views)
Attached Files
File Type: asc Meridian 103 exicon power amp EVO8 RESPONSE.asc (12.6 KB, 11 views)
File Type: asc Meridian 103 exicon power amp EVO8 TIAN.asc (14.3 KB, 8 views)
__________________
RC
  Reply With Quote
Old 20th March 2017, 07:06 PM   #19
RCruz is offline RCruz  Switzerland
nhinstruments
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Meridian 103 clone
C4 acts like compensation cap.

FFT @ 1kHz 1Vacin

Expert opinions are welcome off course
__________________
RC
  Reply With Quote
Old 20th March 2017, 07:29 PM   #20
RCruz is offline RCruz  Switzerland
nhinstruments
diyAudio Member
 
RCruz's Avatar
 
Join Date: Sep 2006
Location: Wallis
Meridian 103 clone
And here is the response ... 26dB at 1khz

I wonder why bass response is not linear....
Attached Images
File Type: png Response.PNG (85.8 KB, 160 views)
Attached Files
File Type: asc Meridian 103 exicon power amp EVO8 RESPONSE.asc (12.6 KB, 13 views)
__________________
RC
  Reply With Quote

Reply


Meridian 103 cloneHide 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
Meridian M2 clone - driver recommendations 68Spider Multi-Way 26 30th August 2016 07:20 PM
JVBDigital Vanity Lite 103 full resolution digital output board for Oppo BDP-103/103D noah katz Swap Meet 1 20th June 2015 10:47 PM
Meridian 103 overheating Impman71 Solid State 7 10th April 2012 10:15 AM
Can Anyone Identify This Component in Meridian 103/5 Power Amps Please? Thomo Solid State 13 26th April 2010 11:39 AM
Meridian 103 - bdy56 Transistor Alternatives? Thomo Parts 11 25th February 2008 02:26 PM


New To Site? Need Help?

All times are GMT. The time now is 08:30 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki