Passive Phono Preamp using National LME49710

[binspaul]

Hi,

I am planning to develop a passive phono preamplifier using National LME49710. In the attached document, Figure 2, what exactly is the purpose of the IC's U4 and U5?

Also, I was planning to use Hagerman Bugle power supply. Is this a good match to the pre or do it needs improvement?

Best regards,
BP

 

[Speedskater]

But phono pre-amps are not passive.

********************************
This is the 'chip-amp' sub-forum.
Your question should be in the 'analog source' sub-forum.

 

[SY]

Those chips provide a low noise power supply rail.

I'll move this thread to the more appropriate forum.

 

[kamis]

Passive RIAA op-amp phono preamps with low working voltage have poor overload/headroom . With op-amps, fully active RIAA filters are much better.