AD797BRZ vs AD797ARZ

[mab1376]

Whats the major difference between these two?

I'm very new to the diy audio scene so i don't have any idea what the data sheet specs mean.

Thanks in advance!

[stratus46]

Originally Posted by mab1376

Whats the major difference between these two?

I'm very new to the diy audio scene so i don't have any idea what the data sheet specs mean.

Thanks in advance!

http://www.analog.com/static/importe...eets/AD797.pdf

On the top of page 3 you'll find the worst case input bias current is lower for the 'B' grade, the input offset voltage is about half for the 'B' grade and the input offset current is lower for 'B'.

I think there are typos on the power supply rejection spec. A call to the field engineer would clear that up.

Most applications would be fine with the 'A' grade but some uses would benefit from the tighter 'B' specs. Of course the 'B' chips cost more.

'R' is the SOIC-8 package likely in tubes of 25 or 50 pieces. 'Z' means RoHS compliant. Are you sure you wouldn't find the DIP-8 package easier to work with?

Anything else?

G²

[mab1376]

awesome! thanks!

i had one other question,

what the difference between the OPA637AU and OPA637SM? and is it worth the crazy money difference?

Auzentech, Inc. OPAMP
Auzentech, Inc. OPAMP

The AU is $70 whereas the SM is $250

Also whats the difference between the 627 and 637? according to Auzentech the 637 is better for rock music and the 627 is better for classical, but I'd like some actual user feedback if possible.

[alexberg]

Originally Posted by mab1376

awesome! thanks!

i had one other question,

what the difference between the OPA637AU and OPA637SM? and is it worth the crazy money difference?


The AU is $70 whereas the SM is $250

Can't you see what grade metal can part is? http://focus.ti.com/lit/ds/symlink/opa637.pdf

[mab1376]

I have no idea what any of this means, all i know is how it sounds by actually trying something.

As I said I'm very very new to all of this and kinda need some guidance as to what im looking at and what these specs actually means when it comes to using it in a real component.

[BrianL]

Well, if you don't know what any of this means, then I must caution you that the AD797 requires proper care and feeding -- because of its design, it's much more sensitive to lots of subtle things than other amps.

There are several good tutorials. One is Ron Mancini's "Op-amps for Everyone" downloadable from http://www.ti.com. There's also Walt Jung's "Op-amp Cookbook" or "Audio Op-amp Applications" as well as ap-notes from other analog semiconductor companies. You can probably find some college course 'class notes' (i.e., PowerPoint presentations) via google.

[dsolodov]

Originally Posted by mab1376

awesome! thanks!

i had one other question,

what the difference between the OPA637AU and OPA637SM? and is it worth the crazy money difference?

Auzentech, Inc. OPAMP
Auzentech, Inc. OPAMP

The AU is $70 whereas the SM is $250

Also whats the difference between the 627 and 637? according to Auzentech the 637 is better for rock music and the 627 is better for classical, but I'd like some actual user feedback if possible.

OPA637 has ~ double the slew rate of OPA627. OPA637 is not stable fo rgain less than 5. AU and SM are different grades. SM is definitely better, but it's not worth the $$$ difference on a sound card due to power supply.