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

Class D Switching Power Amplifiers and Power D/A conversion

iNuke 1000 - modifying crossover freq
iNuke 1000 - modifying crossover freq
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 2019, 09:17 AM   #1
fatpizza is offline fatpizza  Romania
diyAudio Member
 
Join Date: Sep 2016
Default iNuke 1000 - modifying crossover freq

So I have the non dsp version because I was using Peace with the onboard 5.1 soundcard as a digital crossover.
Now I've switched to an USB DAC (Topping D10) and I am forced to rely on the 100 hz crossover switch on the iNuke to power my sub.
Anyone know how to modify the internal crossover of the iNuke to a more sensible 60-80 hz (preferably 12db slope)?
  Reply With Quote
Old 5th February 2019, 07:31 PM   #2
Khron is offline Khron  Finland
diyAudio Member
 
Join Date: Jul 2005
Location: Finland
Send a message via AIM to Khron Send a message via MSN to Khron Send a message via Yahoo to Khron
All that seems to be easily-found is the NU3000 schematic, but it's reasonably safe(?) to assume the lower-power version isn't too different.

On page 3 is the line-level circuitry, and the circuitry you'll want to focus on is the one around IC12-B. Looks to be a 3rd order low-pass - an RC low-pass in front of a 2nd order Sallen-Key filter.

Audio Designs With Opamps -2
Active Filters
ESP Download Page
__________________
Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - Shenanigans
  Reply With Quote
Old 6th February 2019, 12:06 PM   #3
fatpizza is offline fatpizza  Romania
diyAudio Member
 
Join Date: Sep 2016
Quote:
Originally Posted by Khron View Post
All that seems to be easily-found is the NU3000 schematic, but it's reasonably safe(?) to assume the lower-power version isn't too different.

On page 3 is the line-level circuitry, and the circuitry you'll want to focus on is the one around IC12-B. Looks to be a 3rd order low-pass - an RC low-pass in front of a 2nd order Sallen-Key filter.

Audio Designs With Opamps -2
Active Filters
ESP Download Page
I filled in the values from the NU3000 schematic in this tool:

(Sample)3rd order Sallen-Key Low-pass Filter Design Tool - Result -

By changing C3 from 10n to 15n it gives me fc1 = 90[Hz] and fc2 = 78[Hz], which is what I need... I think.
Is there any need to change any other components?
  Reply With Quote
Old 6th February 2019, 12:23 PM   #4
Khron is offline Khron  Finland
diyAudio Member
 
Join Date: Jul 2005
Location: Finland
Send a message via AIM to Khron Send a message via MSN to Khron Send a message via Yahoo to Khron
Quote:
Originally Posted by fatpizza View Post
Is there any need to change any other components?
That depends on what you need, or what you're trying to achieve. And/or whether replacing capacitors is easier than resistors (or the other way around).
__________________
Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - Shenanigans
  Reply With Quote
Old 12th February 2019, 03:53 PM   #5
fatpizza is offline fatpizza  Romania
diyAudio Member
 
Join Date: Sep 2016
Quote:
Originally Posted by Khron View Post
That depends on what you need, or what you're trying to achieve. And/or whether replacing capacitors is easier than resistors (or the other way around).
I finally got around to messing with the amp.
I placed a 10n capacitor in paralel with the existing 10n capacitor giving me a crossover freq of 65Hz and it seems to be working just fine.
I have the amp hooked up via RCA to unbalanced TS adapters, and I noticed the amp works with just the inner contact of the RCA plugged in the adapter, is this normal?
  Reply With Quote
Old 12th February 2019, 04:08 PM   #6
Khron is offline Khron  Finland
diyAudio Member
 
Join Date: Jul 2005
Location: Finland
Send a message via AIM to Khron Send a message via MSN to Khron Send a message via Yahoo to Khron
Glad to hear all is well.

And sounds normal enough, assuming the signal source is earthed somewhere (in order to complete the circuit).
__________________
Khron's Cave - Electronics - Audio - Teardowns - Mods - Repairs - Projects - Music - Rants - Shenanigans
  Reply With Quote

Reply


iNuke 1000 - modifying crossover freqHide 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
Pls help with modifying DSP crossover Hydrogen Alex Digital Line Level 8 13th November 2018 03:12 PM
What crossover freq. for these 3-way drivers emretelci Multi-Way 24 5th August 2016 08:19 AM
Active crossover freq for TLK TL6 - suggestions? aspringv Multi-Way 2 10th January 2012 10:36 AM
Hi-freq Active Crossover Needed HipoFutura Solid State 6 30th July 2006 09:22 PM
HP crossover help (+ resonant freq) Dr. Apathy Parts 3 14th February 2006 12:39 AM


New To Site? Need Help?

All times are GMT. The time now is 07:49 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©1999-2019 diyAudio
Wiki