Opamp upgrade in Sony SCD 777es to AD8610?

[PhopsonNY]

Hi there,

I fully admit I am new to DIY at this level, but I was wondering what anyone thinks of replacing the audio board opa2604 opamps in the SONY SCD 777es with the new Analogue Devices AD8610 opamps?

My research suggests that this opamp outperforms the opa627 with the added benefit of a more neutral midrange and speed of the ad825 with deeper bass response.

Any thoughts or suggestions?

TIA

[sonnya]

The max. working voltage on the AD8610 is +/-13.5V
Check the rails. Normaly it is +/-15V or more

If you mount them. Check if they oscillates at the output?. If the oscillates maybe they need better decoupling.

Sonny

[PhopsonNY]

Hey Sonnya,

thanks for the feedback.

Lcaudio.com and audiocom-uk.com make dual AD825 modules with decoupling capacitors on them.

If I replaced the AD825s ont hes modules with the AD8610s, is you think that might make it work?

[sonnya]

Should be no problem.

Sonny

[John S.]

The 2604 is supposed to be a pretty good IC. As a fellow 777 owner, I've been tempted to get mine modded, but the fear of having it develop problems and the need to use the warranty have kept me from doing this. I hope and pray that I never need to send it out. I gather that there have been some issues with these units regarding the spindle/motor/sled section. Y ou may want to think twice about doing any mods. I DO admit that the temptation is great though.

[PhopsonNY]

Hi John,

I must admit this is an issue, but I have lready made several mods to my 777 and I am extremely happy.

If you are ver tempted here are the 2 mods that you have to do first. I found that they greatly improved my players perfromance.
I also shanged a number of passive components, but they are another story.

1. Replace the rca jacks with WBT, CARDAS or other high spec jacks and at the same time you simply must do #2.

2. Wire the audio signal directly to the jacks from the audio board bypassing the pin board.

3. Reconfigure the grounding.

See the following llinks:

http://www.audioasylum.com/forums/hi...ges/41691.html

http://ryoko.telhope.com/~tkchan/777mod/777Mod.html

[John S.]

I've done this kind of stuff to lesser players,along with changing output IC's. I'd like to see someone come out with a kit of parts and instructions for doing a full mod.

[PhopsonNY]

modwright.com has a whole tube output stage he offers.

I am actually waiting for;

www.vacuumstate.com

they have a kit that taps the vc24 chip and bypasses the rest of the audioboard right to a whole new set of output jacks.

They take the bitsream feed and use a low pass filter with on a separate pc board with its own power supply.

They actually give a choice or single ended or balanced outputs.

This will shortly be available as a full kit with instructions for the SCD777es.

I am indulging my hobby as I know the vacuumstate's kit will be better than the opamps, but I would like to see how much better it is than the best opamp driven signal.

[John S.]

The modwright site seemed to be disfunctional,so couldn't find anything about them. And I'm somewhat leary of circuits that use the 6DJ8/6922/ECC88/7308 family of tubes. I was a former owner of an Audible Illusions preamp that I became very dissatisfied with. Sounded more like solid state.After a bit of reading around, I discovered that others felt the same about equipment that uses this tube. I've found a 12AX7A(I use 5751's) based preamp more pleasing to my ear, but as they say... YMMV. Each to his own.

[Brussel Sprout]

Vacumestate's board sounds interesting. I wonder if the LCAudio Zap Filter can be connected directly to the bitstream output? - It's a bit cheaper than the Vacumestate mod, but doesn't include labour...


-Mark.