what could be the reasons for High freq roll off after 14khz - Page 3 - 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 2013, 04:51 PM   #21
diyAudio Member
 
Join Date: Aug 2012
i have this amp also which is the current one that im using
http://www.connexelectronic.com/docu...ier_Module.pdf
which has the same output RC RL networks.. so expect the same from both the modules..
  Reply With Quote
Old 4th February 2013, 04:56 PM   #22
diyAudio Member
 
Join Date: Nov 2005
What are you using for a signal source during your frequency response test? It would be much more likely that a cheap computer sound interface rolls off at 14k than a power amplifier. I don't see anything in the amp schem that would do it. Did you do a loopback test from source to mic input?
  Reply With Quote
Old 4th February 2013, 04:59 PM   #23
diyAudio Member
 
Join Date: Aug 2012
no R31 is not getting hot...
I cant see the values on the capacitors here..
is there any problem in the circuitry? you can see the image of that here..
http://connexelectronic.com/images/2...4702%20BPL.jpg
  Reply With Quote
Old 4th February 2013, 05:01 PM   #24
diyAudio Member
 
Join Date: Aug 2012
the test was done by a professional sound engineer i have seen the RTA on his mac which was showing clear rolloff one the curves after 14k...

well actually If the speaker out is connected before the inductor it sound fabulous... but after the inductor it rolls off..
  Reply With Quote
Old 4th February 2013, 05:04 PM   #25
diyAudio Member
 
Join Date: Jan 2011
Location: Fosser, Aurskog-Holand, Akershus, Norway.
you bought this as an assembled kit?
__________________
Sooner or later you end up with TANDBERG
  Reply With Quote
Old 4th February 2013, 05:09 PM   #26
diyAudio Member
 
Join Date: Nov 2005
You'd need something like a .2 ohm load for the 1uH inductor to cause audio band rolloff. You have something unaccounted for going on. If you have an RTA, why ask? Measure.
  Reply With Quote
Old 4th February 2013, 05:10 PM   #27
diyAudio Member
 
Join Date: Aug 2012
yeah i first wanted to see the quality and if it really worth the effort and then work on the own design knowing what are all the mistakes and any imp tips that I know before go for a decent design... but see found a bug kinda thing so just to know these first..
  Reply With Quote
Old 4th February 2013, 05:12 PM   #28
diyAudio Member
 
Join Date: Aug 2012
my friend has RTA i dont have but it was clear even by listening

so you say that using .5ohm added to the inductor will actually make it rolloff?
  Reply With Quote
Old 4th February 2013, 05:19 PM   #29
diyAudio Member
 
Join Date: Jan 2011
Location: Fosser, Aurskog-Holand, Akershus, Norway.
Quote:
Originally Posted by rhythmsandy View Post
my friend has RTA i dont have but it was clear even by listening

so you say that using .5ohm added to the inductor will actually make it rolloff?
0.1 to 0.5 should do the trick.
What are the physics on the coil? .18uH seemed a little too, eh, little.
(Wich should be good, since the rolloff probably woult be worse if the coils induction gets higher. )
__________________
Sooner or later you end up with TANDBERG
  Reply With Quote
Old 4th February 2013, 05:33 PM   #30
diyAudio Member
 
Join Date: Aug 2012
Quote:
Originally Posted by TANDBERGEREN View Post
0.1 to 0.5 should do the trick.
What are the physics on the coil? .18uH seemed a little too, eh, little.
(Wich should be good, since the rolloff probably woult be worse if the coils induction gets higher. )
0.1uH to 0.5uH?

if so what should be the resistor in parallel with it? it should be same?
  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
Mic preamp - strange high frequency roll off problem Andyroid Tubes / Valves 31 6th January 2013 09:08 PM
HELP: Eimac 75TL amp high frequency roll off HP8903B Tubes / Valves 71 30th April 2012 03:53 AM
Buffers high freq loss trv Construction Tips 21 22nd May 2010 10:53 AM
TDA1562Q low freq roll-off DrLex Chip Amps 7 8th December 2009 02:37 PM
H-Frame High Frequency roll-off? DIY_newbie Multi-Way 7 13th September 2005 04:06 AM


New To Site? Need Help?

All times are GMT. The time now is 06:00 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