Simplistic NJFET RIAA - Page 453 - diyAudio
Go Back   Home > Forums > Source & Line > Analogue Source

Analogue Source Turntables, Tonearms, Cartridges, Phono Stages, Tuners, Tape Recorders, etc.

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 21st August 2010, 12:29 AM   #4521
diyAudio Member
 
Join Date: Apr 2003
Location: Southern Tier NY
Saw the same thing using Arta. Installing drivers for the E-MU 0404. Lets hope for better. I want to get a good set of measurements on the RIAA
__________________
Living Life Doing the Waltz in 4/4 meter.
  Reply With Quote
Old 21st August 2010, 12:39 AM   #4522
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
The resolution is good. The Riaa will hover higher anyway. Any residual tip stuff we can count out now we saw the raw loop. No worries. But its a nuisance you can be better off cleaning if possible with the EMU.
  Reply With Quote
Old 21st August 2010, 03:19 AM   #4523
diyAudio Member
 
Join Date: Apr 2003
Location: Southern Tier NY
No Joy. WIll have to work on it tomorrow
__________________
Living Life Doing the Waltz in 4/4 meter.
  Reply With Quote
Old 21st August 2010, 05:42 AM   #4524
diyAudio Member
 
Join Date: Apr 2003
Location: Southern Tier NY
Technically it is tomorrow I guess. Found the issue with the sound card, it was the driver. Took me many hours of frustration to find it. Back to M-Audio card as it has a lower noise level in this set-up.

Taken at 48000, 65536FFT Blackman. 0dB = 1Vrms
Attached Images
File Type: jpg 1kHZ FFT fixed.jpg (193.4 KB, 158 views)
File Type: jpg white noise fixed.jpg (189.3 KB, 149 views)
__________________
Living Life Doing the Waltz in 4/4 meter.
  Reply With Quote
Old 21st August 2010, 08:51 AM   #4525
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
I guess thats clean enough. Congrats.
  Reply With Quote
Old 21st August 2010, 12:03 PM   #4526
AndrewT is online now AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
in your previous plots the 60Hz and the +-180Hz sidebands on the 1kHz were almost certainly mains and intermodulation with the third harmonic.

Your latest seems to have lost that mains interference.
__________________
regards Andrew T.
  Reply With Quote
Old 21st August 2010, 12:51 PM   #4527
diyAudio Member
 
Join Date: Apr 2003
Location: Southern Tier NY
I agree as it makes perfect sense, but the only real difference between the good and bad was the software.dll used for the signal generation. I was able to repeat the same results and symptoms this morning.

Why is the third harminic so dominant?

I ask this as I have the RIAA hooked up right now. I don't see sidebands to the signal but I do see 60,120,180..... with the odd harminics spraying up into the higher freqs.
__________________
Living Life Doing the Waltz in 4/4 meter.

Last edited by SGregory; 21st August 2010 at 12:54 PM.
  Reply With Quote
Old 21st August 2010, 01:01 PM   #4528
AndrewT is online now AndrewT  Scotland
diyAudio Member
 
Join Date: Jul 2004
Location: Scottish Borders
I don't know why the odd harmonics become so dominant. But they are the source of the buzz we hear when the PSU to Amp connection is not quite right.
__________________
regards Andrew T.
  Reply With Quote
Old 21st August 2010, 01:10 PM   #4529
Salas is offline Salas  Greece
diyAudio Chief Moderator
 
Salas's Avatar
 
Join Date: Oct 2002
Location: Athens-Greece
Or show low level oscillations.
  Reply With Quote
Old 21st August 2010, 01:22 PM   #4530
diyAudio Member
 
Join Date: Apr 2003
Location: Southern Tier NY
How much of the issue could be related to incoming power quality? Just put my probe on the AC line-in and it looks like a triangle wave with the tops and bottom cut off tp fit it into 120V.
When I look at the harmonic spectrum closer it kind of looked like a triangle spectrum.
Attached Images
File Type: jpg Idle FFT.jpg (201.2 KB, 122 views)
__________________
Living Life Doing the Waltz in 4/4 meter.
  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



New To Site? Need Help?

All times are GMT. The time now is 05:17 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