Phono preamp with NJM2068DD

[bocijo]

Hello. I'm trying to build my own phono preamplifier, and i found some schemes over the net. I'm interested in this one, but i have a question about the grounding solution adopted in the circuit. I posted two images with the scheme and the power supply (the bridge part). I'm working on the PCB now, and i will posted when i'm finished designing it .. until then i'm waiting for opinions about the scheme. cheers.

P.s. I was also thinking of replacing njm2068d with tl 071. What do you think ?

[danzup]

Originally Posted by bocijo

Hello. I'm trying to build my own phono preamplifier, and i found some schemes over the net. I'm interested in this one, but i have a question about the grounding solution adopted in the circuit. I posted two images with the scheme and the power supply (the bridge part). I'm working on the PCB now, and i will posted when i'm finished designing it .. until then i'm waiting for opinions about the scheme. cheers.

P.s. I was also thinking of replacing njm2068d with tl 071. What do you think ?

Both capacitors in pics are for grounding of the case (enclosure) and the first one is connected to the ground terminal of 230V c.a. sector .
TL071 have bigger slew rate and lower noise than njm so it is ok .

[bocijo]

thanks a lot i suppose it's something like a loop circuit breaker .. http://sound.westhost.com/earthing.htm

also what does the LC combination on the stage input does ?? i think it's a low pass filter, but for what ?

[mjf]

also what does the LC combination on the stage input does ?? i think it's a low pass filter, but for what ?[/QUOTE]

hello.
this should be a filter for radio frequency.
greetings.........