OPPO DV-970HD modification - diyAudio
Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, 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 16th August 2011, 09:23 AM   #1
diyAudio Member
 
Join Date: Apr 2008
Default OPPO DV-970HD modification

I have OPPO DV970 which I have bought from ebay because of very positive review.

The first impression was very good. I have liked the fat and musical sound, the bottom and middle frequency seems to be fine but the top end was not so good. After one-two hour of listening the sound of the Oppo is tiring me.
I have spend many hours with oscilloscope to measure and many hours to listen my oppo to improve the sound. Because I have only one Oppo DV970 player I have use the other player for reference which is with the some DAC CS4360 inside but with tube out section. However here is what I have done mostly on the power supply section.

Here is schematic and board of the SMPS.
Attached Files
File Type: pdf OPPO Power supply.pdf (68.2 KB, 129 views)
File Type: pdf OPPO Power supply board.pdf (175.7 KB, 75 views)
  Reply With Quote
Old 16th August 2011, 11:07 AM   #2
diyAudio Member
 
Join Date: Apr 2008
Here is the power supply and current for the different line:
- 3.3v digital section for MediaTek take 0.75 A and are well regulated with very low noise.
- 5V digital and analog power supply of the DAC take 0.05A and is very bad regulated with a lot of noise. After checking what cause this noise I have noted that the motor drive servo control circuit is connected together with digital/analog DAC power supply.
- 5V power supply of the motor servo control take 0.5A
- (+9V and -9V) for opamp's take 0.01A and are very well regulated with low noise especially at -9V.

So my purpose was to separate the 5V DAC supply from BA5954 motor servo control.

The PCB is very well made with a lot of holes and jumpers so the work is easy.
I have try many way to made well controlled power supply line with low noise but the most proper manner is to force SMPS feedback circuit to control 5V line not 3.3V. This is done by removing jumper JP502 and place jumper at JP506 and change resistor R509 with 3.3K. Now the 3.3V line will be post regulated from 5V line via UZ1084-3.3 device. For this purpose TC505 and TC506 was increased to 1500uF (I have use Rubicon MBZ 1500uF/16V) and L507 was increased to 3A. For the diode D510 I have try MSR860, 1N5822, FR307, SF36, HER307, SR360 but the best working diode is SR580. For UZ1084 I have use 470uF/16V for input and output. D513, TC514, L506 and TC510 should be removed if you want to free the space. In every case D513 must be removed. Install UZ1084 in place of JP507 or JP514 (I cannot remember) because there is close +5V input, GND and 3.3V output. Now we have excellent 5V and 3.3V power supply.
  Reply With Quote
Old 16th August 2011, 12:41 PM   #3
diyAudio Member
 
Join Date: Apr 2008
For the 5v analog/digital DAC power supply remove jumper JP501 which connect the two 5v line and place D507, TC515, L509 and TC508 to build separate 5V line. For D507 I have use SR580 again but the holes should be enlarged. Measure the new 5V line and If everything is fine you should read 5.45V on this line. If the line is below 5.45V change the R509 with 3.4k, 3.6k so that you have 5.45V. Now the 5V line will be post regulated from 5.45V line via LD29150 device. I have use LD29150 in DPAK package.
For the input pin put 470nF and for the output pin 33uF/10v. I have install it in place of JP520. Now 5v analog/digital DAC power supply is ok.

Last edited by ivodonchev; 16th August 2011 at 12:44 PM.
  Reply With Quote
Old 16th August 2011, 12:53 PM   #4
diyAudio Member
 
Join Date: Apr 2008
Here is schematic of main board
Attached Files
File Type: pdf Main Board schematic.pdf (110.4 KB, 129 views)
File Type: pdf Main Board.pdf (115.6 KB, 61 views)
  Reply With Quote
Old 16th August 2011, 02:27 PM   #5
diyAudio Member
 
Join Date: Apr 2008
In the main pcb place capacitor TC231 and TC236 which are missing. I have use 47uf/25v Elna Silmic II. Remove all ceramic capacitor near opamp (C2138,........,C2143) and place two 47uF/25v Silmic II for +/-9V near TC220. Use the GND hole of TC220 for the Silmic's and the other legs of caps directly to the +9 and -9V trace (scratch the trace).
  Reply With Quote
Old 25th September 2012, 07:12 PM   #6
diyAudio Member
 
Join Date: Sep 2012
Hi, thanks for the schematic. Do you happen to have one for the power supply of the 981HD? I am trying to repair it, and while the power supply for the 970 appears similar, the part designators are different. I am trying to determine the value of R511, which is burnt.
  Reply With Quote
Old 25th January 2014, 05:56 AM   #7
jaxparo is offline jaxparo  United States
diyAudio Member
 
Join Date: Jan 2014
I also need a schematic for the DV-981HD. I need the value of R511 also. I suspect it's 1.5KΩ same as the DV-970, but I'm not sure? Anyone got this schematic?
  Reply With Quote
Old 28th January 2014, 07:30 AM   #8
tvicol is offline tvicol  Romania
vicol-audio.ro
diyAudio Member
 
tvicol's Avatar
 
Join Date: Jan 2005
Location: Bucharest
Send a message via Yahoo to tvicol Send a message via Skype™ to tvicol
Here are some modifications I made on OPPO's.
Look, learn and implement. Mod's can be extended to a higher level - it is up to your budget and what you want to obtain.

vicol audio : oppo 980h audio tuning
vicol audio : oppo 981hd audio tuning
vicol audio : oppo dv-983h audio tuning

Regards,
Tibi
__________________
Shiga 2013 GB SHIGA MKII
Vicol-Audio
  Reply With Quote
Old 28th January 2014, 03:03 PM   #9
marce is offline marce  United Kingdom
diyAudio Member
 
Join Date: Jun 2007
Location: Blackburn, Lancs
Quote:
Remove all ceramic capacitor near opamp (C2138,........,C2143)
Doesn't this remove the higher frequency decoupling caps?
  Reply With Quote
Old 29th January 2014, 06:38 AM   #10
tvicol is offline tvicol  Romania
vicol-audio.ro
diyAudio Member
 
tvicol's Avatar
 
Join Date: Jan 2005
Location: Bucharest
Send a message via Yahoo to tvicol Send a message via Skype™ to tvicol
Quote:
Originally Posted by marce View Post
Doesn't this remove the higher frequency decoupling caps?
Decoupling caps used in OPPO are very cheap X7R. These exhibit very high piezoelectric effect. Beside this X7R have huge variations with temperature and potential applied. In the end, instead to get rid of HF noise, you are inducing a lot of noise in audio band due piezo-efect.
Up to 400Khz an Vishay or Arcotronics MKT/MKP will have same ESR as the ceramic one, without any X7R mentioned problems.

Regards,
Tibi
__________________
Shiga 2013 GB SHIGA MKII
Vicol-Audio
  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
Oppo DV-983H service manual or schematics? Audio Maniac Digital Source 0 11th August 2011 12:10 PM
Oppo Digital DV-981HD f/s garage1217 Swap Meet 2 6th January 2011 06:19 PM
DC Offset in Oppo DV-981HD sonidos Digital Source 7 23rd September 2010 01:27 PM
OPPO DV-980H Service Manual volturnofelix Digital Source 2 14th November 2009 09:21 PM
Oppo DV-981HD output impedance vizion Digital Source 4 23rd May 2008 11:23 AM


New To Site? Need Help?

All times are GMT. The time now is 07:32 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