[jboehle]

Has anyone used AD8397 in a simple CMoy-like amp yet? Seems like it could have the current to drive Grados well?

 

[rickcr42]

use the search feature.Lots of info on this chip

(the short answer is yes,for about eight months

)

 

[grawk]

There's at least 1 commercial amp that's got a very simple circuit (much like the cmoy) using an 8397. It's reported to sound as good as VERY expensive amps, and can drive both low current high resistance and high current low resistance cans well from a single 9V.

 

[Porksoda]

The input current is pretty substantial, since its bipolar. According to the datasheet it'll slew 25 V/us into 25 ohms on the upswing and about 22 on the downswing. It's frequency compensated aswell, so it rings. But still, 250mA rail to rail into 25 ohms, with really low distortion and noise is a hell of an accomplishment, especially at the $4.50 price point. I just might have to buy one and see how it compares to the AD8620 for grados

 

[Nisbeth]

There have been a few threads on the AD8397 over at headwize and Tangent is cooking up a successor to the Mint using this chip

/U.

 

[rickcr42]

Quote:

I just might have to buy one and see how it compares to the AD8620 for grados

head to head will whips its a*s in a straight "single opamp/single stage" amplifier as it does most single opamp designs (no buffer,no fancy grounds,no discrete output stage just straight opamp) driving Grados

 

[dsavitsk]

The datasheet suggests that this opamp needs a gain of at least 2 in order to run rail to rail. Does anyone have any experience in using it in unity gain, or have any experience with good operating points?

 

[rickcr42]

Quote:

The datasheet suggests that this opamp needs a gain of at least 2 in order to run rail to rail. Does anyone have any experience in using it in unity gain, or have any experience with good operating points?

Why would you want to use an opamp at "unity" when a buffer not only works better at that but is specifically designed for the application ?
Grados and +6bB (x2) is a good match in my experience.

Just wondering

 

[jboehle]

Quote:

Originally Posted by rickcr42 use the search feature.Lots of info on this chip

Doh, I did use search, but only searched for '8397'. 'AD8397' turns up quite a bit more...my bad!

 

[Porksoda]

Quote:

Originally Posted by rickcr42 head to head will whips its a*s in a straight "single opamp/single stage" amplifier as it does most single opamp designs (no buffer,no fancy grounds,no discrete output stage just straight opamp) driving Grados

In your opinion, how does the sound of the two compare?

 

[rickcr42]

like someone flipped on the bass boost.Not "boom boom boom" but added weight from the upper midrange area down while still maintaining good detail.Something like adding a buffer to the 8620 sounds even though that chip also has great current delivery by itself.
Might just be a Grado/8397 synergy thing but the best single opamp stage device I have used yet in this application even though I am not big on opamps and much prefer discrete.

 

[Pars]

Where can you get the AD8397? Digikey doesn't appear to stock it, and has a minimum of 98 units. The AD8620 MINTs I have built are somewhat thin sounding, particularly compared to my Gilmore.

 

[rickcr42]

http://www.analog.com/salesdir/count...&countryID=210

I actually have a regional right down the road