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

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

Pioneer PD9700 analogue stage question
Pioneer PD9700 analogue stage question
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 12th November 2010, 08:13 PM   #1
paulrerrie is offline paulrerrie  United Kingdom
diyAudio Member
 
Join Date: Jan 2008
Default Pioneer PD9700 analogue stage question

Hi. I was just curious to know, do R577 & C567 (see schematic) form a (12KHz) low pass filter? The stage is described as 'Buffer & de-emphasis' & I wondered if this was intended to actually filter the audio signal rather than decouple digital/RF noise.

Thanks, Paul
Attached Images
File Type: jpg Output stage.JPG (71.4 KB, 52 views)
  Reply With Quote
Old 13th November 2010, 12:03 AM   #2
SoNic_real_one is offline SoNic_real_one  United States
diyAudio Member
 
Join Date: Jan 2008
Location: Virginia
Looks like that. If the 0.0056 is a 5.6nF capacitor...
  Reply With Quote
Old 13th November 2010, 07:41 AM   #3
Mooly is offline Mooly  United Kingdom
diyAudio Moderator
 
Mooly's Avatar
 
Join Date: Sep 2007
Pioneer PD9700 analogue stage question
The whole opamp stage forms what's called a "multiple feedback" filter and is inverting at DC. The opamp is configured as an integrator (C565) and it's performance is hugely opamp dependant. That may be one reason why the stage uses FET's to boost output stage current delivery.
  Reply With Quote
Old 13th November 2010, 10:31 AM   #4
paulrerrie is offline paulrerrie  United Kingdom
diyAudio Member
 
Join Date: Jan 2008
Wikipedia calls it a 'multiple feedback topology' and from the corner frequency calculation, it only appears to be filtering at very high frequencies.
  Reply With Quote
Old 13th November 2010, 12:51 PM   #5
SoNic_real_one is offline SoNic_real_one  United States
diyAudio Member
 
Join Date: Jan 2008
Location: Virginia
The integrator made with C565 (680pF) is filtering very high. But the one at the input was in question... Is a simple low-pass with 2k4 resistor and 5n6 capacitor. That has -6dB at some 11.8 kHz.
  Reply With Quote

Reply


Pioneer PD9700 analogue stage questionHide 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
Analogue output stage maxpou Digital Line Level 0 18th April 2009 03:48 PM
Help on improved analogue stage p.heimpold Digital Source 1 17th March 2007 10:16 AM
Shematic for Pioneer pd9700 petronius Digital Source 0 16th February 2007 10:56 PM
Harsh trebble after clock upgrade on Pioneer PD9700 wreeve Digital Source 12 23rd September 2005 05:20 PM
TDA1540 analogue stage dariusku Digital Source 2 9th September 2005 08:01 AM


New To Site? Need Help?

All times are GMT. The time now is 09:39 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio
Wiki