Go Back   Home > Forums > >

Digital Line Level DACs, Digital Crossovers, Equalizers, etc.

DSP Xover project (part 2)
DSP Xover project (part 2)
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
Old 15th January 2021, 09:17 AM   #3521
jbator is offline jbator  Poland
diyAudio Member
 
Join Date: Aug 2005
Quote:
Originally Posted by 30m20 View Post
@jbator: Yes, I know how to workaround practically. It is only a question of interest, why Nick wrote this - or in other words: why not correct via positive post-gain?
Because of processing with high slopes you will have some small spikes in signal. You can try to post gain but on some material it will fire clipping notification.
  Reply With Quote
Old 16th January 2021, 01:34 PM   #3522
30m20 is offline 30m20  Europe
diyAudio Member
 
Join Date: Jul 2011
@fluid: then the question is, why there are two gains at all: if we are only allowed to diminuish, this could be done with pre-gain alone.....


@shining31: maybe minidsp has an advantage (only this one!): there might be enough headroom for processing.

But: what is enough? - Noone knows, how much gain the user wants for his deep bass frequencies. So, giving responsibility to the user might not even be a disadvantage.
  Reply With Quote
Old 16th January 2021, 04:15 PM   #3523
Shaun is online now Shaun  South Africa
diyAudio Member
 
Shaun's Avatar
 
Join Date: Aug 2001
Location: Cape Town, South Africa
Quote:
Originally Posted by 30m20 View Post
@shining31: maybe minidsp has an advantage (only this one!): there might be enough headroom for processing.
If by advantage you mean "dumber", then yes. Such is the risk of putting out a product with many tweakabilities and flexibilities: not everyone (i.e., very few) will appreciate it all. However, Nick's caveat still applies to miniDSP. Gain staging is simply about using the available dynamic range to maximum benefit. Nick was mindful to include physical LED indicators as well as graphical indicators in NUC to alert the user to clipping.
__________________
Shaun Onverwacht
|||||||||| DON'T PANIC ||||||||||
  Reply With Quote
Old 16th January 2021, 10:15 PM   #3524
fluid is offline fluid  Australia
diyAudio Member
 
Join Date: Jan 2009
Quote:
Originally Posted by 30m20 View Post
@fluid: then the question is, why there are two gains at all: if we are only allowed to diminuish, this could be done with pre-gain alone.....


@shining31: maybe minidsp has an advantage (only this one!): there might be enough headroom for processing.

But: what is enough? - Noone knows, how much gain the user wants for his deep bass frequencies. So, giving responsibility to the user might not even be a disadvantage.
Maybe to cater for the situation for when the input signal is too low coming in to the Najda. Lots of effects channels have "make up gain" settings. Najda is different in architecture than some other DSP processors and it clips hard so care is needed, the last part you know already.

If the signal is represented as a floating point number in the DSP the headroom is effectively unlimited for audio purposes. If / when it is converted back to integer as it must the gain will have to be reduced to avoid clipping.
  Reply With Quote
Old 17th January 2021, 04:53 PM   #3525
30m20 is offline 30m20  Europe
diyAudio Member
 
Join Date: Jul 2011
@shaun: you did not quote to the end: I think we share a similar opinion about miniDSP, but I expressed it a bit "milder".

Quote:
Originally Posted by 30m20 View Post
But: what is enough? - Noone knows, how much gain the user wants for his deep bass frequencies. So, giving responsibility to the user might not even be a disadvantage.
@fluid: O. K., I was just wondering, but I live with this for years and will continue. Its not a real problem.
  Reply With Quote
Old 29th January 2021, 06:15 PM   #3526
tuyen is offline tuyen  Australia
diyAudio Member
 
Join Date: Oct 2008
Send a message via MSN to tuyen
I accidentally removed of the opamps while the najda unit was still powered on.

Now the unit still powers on but the volume control is no longer working. The output is distorted but can still hear the music pass through but with constant pops every couple of seconds. Adjusting the volume doesnt change the actual outputted volume.

Ive confirmed its not the opamps being the issue. Im suspecting it is just the cs3318 chip (and nothing else). Is there a way i can confirm this? Annoyed with myself for being careless! 😓

Thanks in advance.
  Reply With Quote
Old 31st January 2021, 01:39 PM   #3527
Shaun is online now Shaun  South Africa
diyAudio Member
 
Shaun's Avatar
 
Join Date: Aug 2001
Location: Cape Town, South Africa
If you have the capability, you could probe the input (individually) of the volume control chip. If the signal reaches there intact, you'll know the problem lies downstream. Inserting or removing a component while live can cause damage. In this case, the op amps are powered from a higher voltage than the digital chips. The act of removing an op amp under power can result in an arbitrarily harmful voltage being fed to the neighbouring circuitry.
__________________
Shaun Onverwacht
|||||||||| DON'T PANIC ||||||||||
  Reply With Quote
Old 8th February 2021, 04:53 PM   #3528
Speedysteve7 is offline Speedysteve7  United Kingdom
diyAudio Member
 
Speedysteve7's Avatar
 
Join Date: Dec 2009
Location: Hants/Berkshire/Surrey
Quote:
Originally Posted by tuyen View Post
I accidentally removed of the opamps while the najda unit was still powered on.



Now the unit still powers on but the volume control is no longer working. The output is distorted but can still hear the music pass through but with constant pops every couple of seconds. Adjusting the volume doesnt change the actual outputted volume.



Ive confirmed its not the opamps being the issue. Im suspecting it is just the cs3318 chip (and nothing else). Is there a way i can confirm this? Annoyed with myself for being careless! DSP Xover project (part 2)



Thanks in advance.
I've got a Najda board that half powers up.
The 5v polarity was switched inadvertently DSP Xover project (part 2)
Perhaps one good board could be made out of them both?

I have a new board and a spare one in case that dies DSP Xover project (part 2)
  Reply With Quote
Old 10th February 2021, 04:05 PM   #3529
jbator is offline jbator  Poland
diyAudio Member
 
Join Date: Aug 2005
Quote:
Originally Posted by Speedysteve7 View Post
I've got a Najda board that half powers up.
The 5v polarity was switched inadvertently DSP Xover project (part 2)
Perhaps one good board could be made out of them both? You can also check those two close to 12V connector.
DSP Xover project (part 2)
Did the same with 12V some time ago. Only inductor close to connector broke (it's kind of fail safe/fuse). I have replaced it and board worked fine.
Check one from the attachment.
Info from charpaK recieved then
"This small inductor is rated for roughly 0.4 A and will fry if the current exceeds that value - typically a short circuit - so it acts also as a fuse.
Not a big problem! Replacing that part will fix the issue."

This is one I have used as replacement

LQH43MN220K03L MURATA
Inductor: wire; SMD; 1812; 22uH; 320mA; 0.94Ω; 10%; 4.5x3.2x2.6mm
Attached Images
File Type: jpg najda05.jpg (197.9 KB, 92 views)

Last edited by jbator; 10th February 2021 at 04:17 PM.
  Reply With Quote
Old 10th February 2021, 05:02 PM   #3530
nounouchet is offline nounouchet  France
diyAudio Member
 
Join Date: Feb 2012
Location: Lyon
DSP Xover project (part 2)
I had the same problem. I also changed the inductance (same reference) which had completely melted.
nounouchet
  Reply With Quote

Reply


DSP Xover project (part 2)Hide this!Advertise here!
Thread Tools

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
DSP Xover project chaparK Digital Line Level 141 3rd July 2011 11:16 AM
Help Please for simple active Xover project dcathro Analog Line Level 4 9th September 2010 06:47 AM
Violet DSP Evolution - an Open Baffle Project cuibono Multi-Way 211 18th May 2010 03:26 AM
Software digital DSP ... Xover/filters/EQ ?? JinMTVT Digital Source 2 8th October 2004 07:02 AM
DSP card & proper xover for heathkit 859A speaker cabinet x. onasis Multi-Way 6 22nd April 2003 08:39 PM


New To Site? Need Help?

All times are GMT. The time now is 10:13 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki