[gavinbirss]

Hello,

I would like to inform you all of what L C Audio says it a great opamp. Maybe some of you DIYers would want to try this opamp in a headphone amp design.

The slew rate, bandwith and setting time are very respectable.

It is the Analog Devies AD825 (only avail in SMT SOIC)

Although it is only available in SMT you can purchase the AD825 module from L C Audio that is already soldered on a little pcb and then use it as is in a design.

Here is the link :

http://www.lcaudio.com/ad825.htm

You will find a table that compared opamps that they tested and feel are the best for analog output stages for D/A converters in CD player DAC's.

I would appreciate any feedback on using this opamp in new / current headphone amp designs.

It may be argued that the same or greater bandwith can be archieved by using BB 143 / BUF634 or any opamp and BUFFER.

 

[Tomo]

Hello,

THS4022 has 470V/usec and 350MHz bandwidth. I built a headphone amp with it. Call that an extreme.

LCAudio has been known to us for a while now. The offer AD825s and convertors for us and we are pretty darn thanksful.

However, lately, HeadWizers are going for AD823 opamps. You should Email Apheared or PPL and ask him directly.

Opamps like OPA634 (High speed High Bandwidth opamps) are very difficult to handle. Even one tiny mistake leads to oscillation. So many people avoid using these. However, do "right" things and you will get pretty good performance out of it like I did with my THS4022.

Tomo

 

[gavinbirss]

Thanks Tomo

Could you email me your info and schematics of your THS4022.

Gavin

 

[aeberbach]

I have a couple of those AD825 modules from LC Audio waiting on my desk. They look great, and are plug-in replacements for the AD843/OPA134 etc. - when life gets back to normal (trip to Peru, Australia, too much work on) I look forward to trying them out. LC Audio were great, accepted a personal check (in $US) and shipped to San Francisco FAST.