Onkyo DX 6850=DX 706 upgrade

[gabrielbecheanu]

Hi
I have a CD made by Onkyo model DX6850 (DX 706 American version) and I would like to make him an upgrade. I study the service manual and I decide to upgrade the digital part of the CD player. One of the difference between DX6850 and 6870 is the clock generator.
I found on EBay an oscillator on the right frequency Vanguard Ultra precision Golden TCXO, 0.3ppm 16.9344MHz - eBay (item 120627335095 end time Jan-26-11 05:42:02 PST)

Any suggestion about my idea to install the new oscillator on the CD player, I will see any differences?
Thanks

 

[aparatusonitus]

Any suggestion about my idea to install the new oscillator on the CD player, I will see any differences?

Simple answer is no, deal with the digital power supply first...you don't want LM7805 as voltage regulator there...use J-fet CCS -> TL431 -> good elcap//film//ceramic for digital supply decoupling at devices pins as possible.

 

[gabrielbecheanu]

Thanks for the info.
I put this question because a friend of mine put another clock in his TEAC VRDS 10S CD player and I sow a huge improvement.
I believe that through this change that I'll enhancing efficiency and performance of this CD player
I made some changes, I changed NJM5532 with OPA 2134 and have removed the muting transistors

 

[aparatusonitus]

You can put rubidium clock inside if you want, but it will not perform one zilch better then simple crystal clock until you deal with grounding and power supply...and remember clock psu is analog psu, not digital!

 

[gabrielbecheanu]

To modify the PSU is too much for me at this time, I must study about CD players modification.
I try to find some tutorials to modify this CD but no one made something like this for this CD player.

 

[gabrielbecheanu]

Hi aparatusonitus
I Received A few days ago the TCXO clock But as you said i think i must start to improve the digital power supply. I sow some pictures on the web But I Would like more specific advice to upgrade this CD. I have the service manual for all Three models (6850,6870,6890) I think you know me better than me all the differences between those CD players.
Can you give me more advice in this project?
An interesting pictures
Thanks

 

[mlloyd1]

it's probably too late for me to say this, but i'll do it anyway
you want a low jitter clock (to help achieve low jitter, the clock will require use of a low noise power supply).
you don't need a "high accuracy" clock - accurate frequency of operation and low phase noise/low jitter are two different things. Search around here more for some helpful background.

I have a DX-706 and DX-6800 myself. To me, a lower jitter clock improves the sound of my DX-706. At the moment, my DX-706 uses the Hagerman clock (info here: Hagerman Technology LLC: HagClock Audio CD Low Jitter Precision Clock Oscillator DIY Kit). Again, search this site for ideas and information about other clocks.

good luck,
mlloyd1

 

[gabrielbecheanu]

Thanks mlloyd1
As you know our CD player can be easily upgrade to DX6870. The main board are the same except some missing parts and transformer. I think I will start to upgrade the power supply an use two transformers instead of one.
I will like to know more how to modify this CD player. I think this CD player has more to offer.
Best regards

 

[gabrielbecheanu]

Hi
Today I almost finish to upgrade the CD player. I have to put four more components near to the Optocoupler two resistor and two capacitors one near to the new oscillator and one near to the Optocoupler. The reason that I don’t put them is that i don’t know the value of them. This components are not in the service manual, the only way is to find a (6870 708) and see the value of them
Any one who has a 708 CD player can tell me the value for these components.
R504
R501
C504
C304

After that the upgrade will be complete
Best regards

 

[SoNic_real_one]

Gabi, I would replace also the Opamps that you have.

I am talking about Q403, 404, 405, 406 - NJM5532 were great back then, but today there are better options. I suggest LM4562.

 

[gabrielbecheanu]

The op amp now is OPA 2134 but I can’t see a difference between 5532 an 2134
I will try LM4562, I use it on my DAC with CS4398 the output was with 5532 but now I have 4562. I like this OP amp.
In the CD player I changed the filter capacitors with Nichicon Fine Gold.

 

[SoNic_real_one]

I wasn't impressed by 2134 either. Not bad, just not sensible better...

 

[stephensank]

The OPA134-series is a WAY better chip than you guys think. The problem is that you don't give it adequate power supply support. The 2134 can deliver serious peak currents to the load, and benefits enormously by very copious, instantly available stored supply energy. The LM4562 sounds a bit etched compared to a properly supplied 2134. If you don't hear a difference from 5532 to 2134, either your remaining system is inadequate or you are strangling the dynamics & richness of the 2134 by typical, woefully inadequate supply support.

 

[SoNic_real_one]

I did test it following a TDA1541. Maybe that was the problem... however, to my ears, the LM4562 performed better in the same place (I/V).
And from this paper results are pointing in the same direction.

 

[apassgear]

Thanks for the invitation, I still have this cd player which is wonderfully constructed I have done numerous tweaks and changes mainly to the dac/audio PCB, for one thing I separated the trafos adding two more, one to the dac and a second to the audio circuit, have change also opamps and several types and brands of output caps. - I gave up, never sounded good, I still use a Magnavox CDP650 on my main system8, highly modified tho.
I have some other DAC's and wish I could do a new board to change completely that board.
So no useful hints or tweaks for this one.

Cheers

 

[gabrielbecheanu]

Hi thanks for your replay.
I use the cd player as transport for a DAC with CS4398 but i always eanted to upgrade this 6850-706 to a 6870-708.
Tomorrow a friend of mine will receive a 6870 and i will know the value for some parts and i will finish mine, i will made some test between them.
I will post here the results of the test.

I like this CD because it is a cheap machine and well build with good components,
Before to start modifying i made a test between 6850 and CEC TL 51xr and also a Yamaha CD S 2000 both are almost 1500 euro.
Conclusion: I like the Onkyo DX 6850 i will never pay 1500 euro for a CD like those two .

Best regards

 

[memoire101]

Hi there I have the Onkyo dx-706 (BH) since 2 days from a relative who never use it. It is brand new (from plastic white paper in the box ) and I want to know if I can upgrade this component to have a near hi-end cd player. If yes what are the pieces electronics parts to change and with witch parts number to change them please ?

Sorry for my english I talk french ( quebec city) ... This player is amazing and built as a tank lol

thks all !

 

[memoire101]

Hi all ! I have a dx-706 brand new since 2 days ( onkyo integra ) and i want to know witch parts to change to make a hi-end cd player ?

thks for your help and advise

Mario

 

[opteron]

Changing op-amps, capacitors etc is wasting time, not always putting better parts give better sound!!! If you want a really good sound producing by this machine cut out analog outputs completely, take signal straight from DAC's in to new and simple analog section with two Ecc88 without opamps and all that stuff. That is very good result solution. But again HiEnd? I doubt... There are much better CD's for such modification (like cheap Denon's, Kenwood... with PCM1702, Marantz, philips etc with TDA1541, Onkyo with PCM58 and much, MUCH more) - with them, You can get far better sound than from 6850/706.

Regards

 

[memoire101]

Thanks Opteron. A friend of mine with this 706 made change as the 2 analogue output and the rotate motor to a brand new motor ( to turn the disk ) . Cause I dont have 1500-2000$ and more so I want to got the most of this onkyo dx-706 . Now just have to find a technician who can bypass the analog plugs ( rca ) and take from the dac signal to a pair of rca high quality output . Thanks for your help .