[morsel]

We need to compare the AD8620 with dual AD8610s to see if the performance is the same. I hope it is. The specs are close, but not identical. Time to get more of the regular BrownDog SO8 to DIP adapters.

http://brndog.com/so8.html

 

[aos]

Yes, you can order them. The price is exactly twice that of AD8610, i.e. it is 12 dollars US. How long will it take for them to ship it to you is another matter.

Canadians, be aware that if you order from Analog you'll have to pay brokerage fees. I have not seen any of their distributors sell AD8610 in small quantities (i.e. less than 100 or even 1000) and it'll probably take them couple of months to even show AD8620 as available on their sites.

 

[PhopsonNY]

Ok time for another stupid question...!!!

As formerly stated, I have 16.6v supply rails for all the opamsp in my SCD777es and I would love to use the ad8620s if they are as good as the ad8610s in my buffer/servo stage and maybe my "mix amp" (balanced to unbalanced) stage. Hence voltage must be reduced to 12v if this is to be possible.

I know Sony suggests and LDO for this but building and installing a daughter board and then cutting the existing supply rails is I know beyond my knowledge/skill. Besides I am not sure what effect it will have on other parts of the system.

Strange Idea, but what if I installed a small resistor at the voltage connection pin of the opamps to be used. I know this is physically difficult, but I remember from High school that V=IR.

I am presuming the current is constant here so with measurement an calculation, I could get this v down to 12.

Please comment and I know I am probably over simplifying the situation.

 

[aos]

PhopsonNY, you can go to www.dddac.de and look at modifications that guy did to his 777ES.

Your idea is not stupid at all, but I'd also add a 12V Zener. As the current that opamp is drawing varies with the signal and the load, voltage it sees on its rail would vary also, which is not good. With Zener it'd be constant. Resistor has to be calculated so that even at highest current (opamp + Zener regulation) voltage is still 12V. Rather than hacking your ultraexpensive player, I'd recommend non-destructive approach, build something on a separate board and feed it from the main board. See website above for some ideas...

 

[ppl]

I noted some strange Things going on with the AD-8512 upon power down and this can damage a current source connected to the output of this opamp unless protective measures are taken. rather that retype i will refer you hear http://headwize.powerpill.org/ubb/sh...ays=20&fpage=2

 

[morsel]

I finally ordered some AD8620 and AD8065 opamps. They should be here in a week or two. It will be fun to critically listen to the entire opamp collection once I get my CD player overhauled and hooked up to a META42.

 

[PhopsonNY]

As I could not do without music anymore, I had to replace the noneworking ad746s in the buffer/servo stage.

I did not want to go back to the ad712s or the ad8512s.

I will have to say that the ad8066s may turn out to be even better when they come out, but these are excellent.

All the bass and lower mid qualities of the ad8512 or maybe the ad8610s, but also the sweet mids and extended highs that were missing from the ad8512.

I cannot say they are as good as the ad8610s as I have not done a direct comparison, but the music is beautiful and lots of fun. I cannot wait till I get round to current loading them to see if I get a further improvement.

This makes me eager to try the ad8065s in the I/V position.
I might even try the ad8066s in the mix amp position too.

 

[ppl]

The AD-8065 and the Dual version i belive are only +/- 12 volt rail max. Ill will check the data sheets again. An Exalent opamps ror 15 volt Rail I/v Convertor use is the LT-1357 and it's dual of whitch resided in my Magnavox CD player for quite a while. I now use the AD-8620 since that player uses +/- 10 Volt rails. Wounderfull I/v opamp, The AD-8610 & 20 are.

 

[PhopsonNY]

Hi PPL,

thanks for the note. The ad8065 is supposed to be able to take up to 24v if I am reading the data sheets right.

It seems to be working just fine in my scd777 in I/V position.
I had ad2064s there originally and then the ad825s. Upon your recommendation I am trying these, current loaded of course and they sound wonderful. I am not exactly sure yet, but it seems the midrange is even more neutral than the ad825s.

The only porblem I have is a continuous hiss noise from the speakers once the mute relays disengage. Noticable from seating position, but not a problem when music is loud.

Newbie question, but what is causing this?