Opamp upgrade in Sony SCD 777es to AD8610?

[fmak]

These things should be banned unless they can be silenced!!!

 

[PhopsonNY]

SCD 777es can use ad8610/ad8620

AD confirmed that these opamps should work fine to a maximum of 26v when voltage is applied to a single rail.
ie is ok up to

+0v and -26v

or

-0v and +26v...

They say it is the total difference that matters... just be that the voltages are well controlled

This is good news for those of us with the SONY SACD Players...

I have the ad8620 in the Buffer/servo position replacing the ad712.

So far Works just fine with single rail voltages of 16v...

Had the ad8610 dual modules in I/V position and they failed, but stupidly forgot to replace a connection when closing up and this may have effected the opamps

 

[NAP 160]

Re: Sacd mods

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:
hi john i have done this mod on two 777es players i have never used the chip you qote. but i replaced the burr brown chip with the AD826 AN and the sound stage opens up, lots more deital bargin upgrade for the price. all the best john
http://www.audioasylum.com/forums/hirez/messages/41691.html

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

 

[Joseph0]

unfortunately, if the internal schematic of a soic8 dual op-amp is the same as an audiocom adapter, making two single soic8 opamps into one 8-dip dual, you are providing each of the two opamps in the ad8620 +16VDC and -16VDC, 32VDC, exceeding the 26V limit.

An externally hosted image should be here but it was not working when we last tested it.

however, the 777es/scd-1 schematic does show the opamps inside the ad712, one receiving a single supply of +16VDC, the other -16VDC, and not a +/-16V dual supply for both, (as though the amps inside AD712 are two completely independant amps with single supply rails). If the V+ and V- pins of the ad8620 are not connected to each opamp, a single V+ for one amp, V- for the other, the 26V limit wouldn't seem to be exceeded.

 

[Joseph0]

the 'regulator amp', IC107, IC207 on Sony board, two of four uses of AD712 is actually supplied +/- 9VDC, so AD8620 is certainly ok there.
the 'line amp', IC104, IC204 is the one supplied +/-16VDC.

 

[peranders]

Are you aware of that you have waken up a thread from the stone age?

 

[Joseph0]

nope. I'm trying to find reason not to unsolder the AD8620's I put in 'line amp' position before finding +/-13V limitation.