Anyone tweaked the Onyko DX7711 integra CD-player?

Is somebody own and tweaked the Onkyo DX7711 integra CD player?
Briefly about the player itself:
The filter/receiver is SM5843AP, and the DAC is 2xSM5864AP, one for each channel, >9kg, robust mechanics. :rolleyes:

If somebody tweaked, what you did it with it?
I just own one, and I would like to change the opamps, but I do not know, which opamp can be suitable.
The existing opamp type is NJM4565DD.
I can not found any datasheet for it, only for the 4560 model.
May I replace it with OPA627 or AD825?
I think the clock circiut can be tweaked with Kwak Clock, but let's see.
My plan also to add one or two more transformers, to have separated for servo, digital and analog sections, change the main cable, and probably some capacitor upgrade (the existing is Nichicon, if remember well).

So, if somebody have practice in it, welcome! I need help!

Thanks in advance!

I have a DX77111 as well. Until now I only have eliminated the muting trasistors and replaced the ouput cap's with some MKP stuff. I' am stiil thinking to replace the complete output section.
Three opamps in a row for the fixed output makes me :mad: . The variabale output has another opamp, another set of muting transistors and output cap and 50 cm more signal path. If interested i can post a copy of the output section.

gr Klaas
Some details of the (fixed) output stage.
Any ideas what tos skip?

greetings Klaas


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Hello Klaas!

Yes, it looks, that the muting transistors can be eliminated.
About DAC: it seems to me, that the output here is balanced, and the first two opamp is for it.
The second two/three has to be modified somehow. Let me think about it a little.

As I have checked the schematics, it looks, that the PS have three sections:
1. Analogue PS, +/-15V, from same AC wiring the +12V for muting transistors supplied
2. Digital PS, separated regulators for servo driver (digital) unit and uP, separated for filter/DAC digital PS, from same AC line the mechanism control unit (motor, servo, etc.) supplied, with separated regulators.
3. PS for display unit (the display can be turned off in various steps), IR receiver, etc., there is nor regulator, only BJTs.

All together is 11 (eleven) regulators originally in the CDplayer, plus the PS for the display and driver unit!

The DACs running in balanced mode (?), one stereo DAC per channel.
But, there is too many opamps after the DACs.
Probably a totally another LPF section should be used? I do not know yet. Maybe the whole analog section can be eliminated and new installed.

JockoHomo, Everybody!
Any idea is welcome to us about this issue. What is your opinion?



2001-06-20 11:27 am
I have an Onkyo DX 706 and the schematics are almost the same as you published(the DAC is SM 5863 but the analog output stage is almost the same).
I have have made the following modifications:

1.Changed all resistors to 1% metal film

2.Changed all capacitors in the filter to Philips 1% polypropylen

3.Changed power supply diodes to BYV27(perhaps schottkys are better ?)

4.Bigger caps in the PS

5.A new transformer to supply the DAC & analog stage

6.Change the voltage regulators(the digital +5V to the oversampling filter & clock circuit and the +5 to each DAC´s analog PS) to LM317

7.New decoupling capacitators (OSCON)

8.Change the electrolytic output cap to a SCR polypropylen 10uF

9.Changed the opamps(I finally settled on the AD797(made some adapterboards because it´s a single opamp),but I have tried OPA2134,2604,OP275,LM6172,AD823(that one is OK).

10. Biasing the opamps to "class A" with a 2mA constant current diode

11.Eliminating the muting transistors

The most of these modifications is not very difficult to make if you have some experience.If you do not want to spend all that money(and time) you should at least try the constant current diode trick...You will notice the difference easy...

Please let us know your results.



2001-06-20 11:27 am
Attach the the diode with the anode to to output of the opamp,
Then the cathode(the one with the ring at it´s side) to pin 4 -Voltage.I used att constant current diode called E202 found at
I think that there are others at RS-components.
I found someone called J506 from Vishay that should work.
The article number in my catalog from RS is :290-8041
I will try to borrow a digital camera and take some photos.

Perhaps someone else can be of any help ??



2001-06-20 11:27 am
Hi Elso
I haven´t tried that yet,but you are probably right.
BUT this tweak is easy to to and cheap,it´s always a start...
Actually the mods I made have been done during long time,and this was one of the best so far along with the change of opamps,resistors & caps(in the filter).

I will probably try the clock-mod some day.
I have got the schematics from you Elso but that was a long time ago so perhaps you could send the latest to me ?

It would be interesting to build a new analog output stage(perhaps some of Jocko´s?)

Hi Elso,
I'm new to this site and have been reading some old threads as this one since i am interested to do some additional tweeks to my CDP such as replacing the digital clock. My rig is an Onkyo Integra 706 some 10 years old but otherwise excellent construction and sounds quite acceptable after all the massage but I'm sure it still can be improved.

The clock, as called by Onkyo information is an AccuPulse Quartz System which unfortuately dosen't say much to me. The DAC's are as you may know single bit data streem.

After reading most of the digital threads I'm sure you are the right person to ask this...

Which clock would you recommend be replaced with?: :confused:
Onkyo DX706 Clock

Hi apassgear,
The right person to ask? I am sure I am the most prejudiced on this one.:eek:
The Onkyo DX704 has a 33.8688 MHz clock according to the LCaudiosite. Chances are that your Onkyo DX706 has the same clock. Please check the frequency on the crystal. It is a oval metallic flattened cylinder.
I have found a source for <B>fundamental</B> mode 33.8688 MHz crystals that work succesfully in the KWAK-CLOCK.
AccuPulse Quartz System bla, bla, bla looks like a good name for my clock:
How about AccuPulse QUACK System?:xeye:
By hitting the e-mail button underlining this post you can get the latest schematic from me. Currently version 6.:)

AccuPulse Quack :scratch: or Kuak or.... sounds great.

BTW Onkyo 704 has different DAC as so does the DX7711, but this last has somthing simillar to the 706.

I have seen that DX 7711 has the NPC SM5864 a 20 bit DAC and the 706 has the SM 5861AP which I suspect is a 16 bit, have been unable to to see the data sheets since NPC discontinued these at the end of last century! and does not show it now on their website.

As for DF the 706 has a SM 5813AP.

BTW the scheme shown by someone on the thread (sory forgot his name and can't go back now in the middle of composing this post, but many thanks to him) related to DX7711 shows a similar
arrangement for the output as has the DX706 (4 OPamps!) which I have replaced with AD827. I mention this because in the near future I would like to have a balanced output.

Have three PS, one exclusive for the clock, well enough bla..bla..bla since my fellow thread readers are much bored with somthing somewhat outtraked from the original thread :eek: :D

P.S. Yea was Klass, thanks Klass nice to retrive this part of the circuit for us, I did needed it very much :)
No problom supplying the schematic ;)

Update about my dx7711. I tried to put the opamps in class A with a fixed resitor (10K) to the positive voltage rail. Also put some adhesive copper tape connected to ground on the DAC.

This cleared thing up a bit.Jus a bit smoother. Not trealy impressing. I'am now playing with a brand new Philips 963SA DVD/SACD player with CD upsampling to 192kHz. Very interesting for about 420 Euro in Netherlands.

If I have to make a ranking

1. SACD very 3D , clear and involving, Speakers disapear, sometimes a bit direct. Asks for attention. (rating 100%)
2. CD at 192kHz, flatter soundstage,high resolution, tonally only a bit less round ,still very clear (rating 80%)
3. DX7711,loses a bit on 2. Mainly in the detailing. (rating rating 70%)
4. 963SA no upsampling. A bit harsh on vocalsssss and cymbalssss, loses more details. Flat soundstage. (rating 50%).

gr Klaas