About a phono preamp

[tiefbassuebertr]

Originally Posted by gaetan8888

Hello

Here is a phono preamp using the LM318 but at pin 1 and 5 it use a super-matched LM394 transistors pair.

The LM318 are a fast op-amp with no rise of distortions in high frequency or at very low level, its an old but good op-amp.

There is more modern op-amps but most of them do have a strong rise of distortions in high frequency or at very low level.

This circuit use an external LTP input to keep the speed but not the noise.

Any opinions, ideas ?

Bye

Gaetan

I have found this circuit by a commercial preamp from "Musical Fidelity" without type number. The model was simply "The Preamplifier"

[tiefbassuebertr]

Here the pdf schematic from this Musical Fidelity Preamplifier:

[Bonsai]

Don't forget that starting at 2120Kz, the RIAA response drops off at 20dB/decade, so this makes the loop gain requirement less onerous than say an amplifer that has a flat transfer function. That said, there still some pretty good new op-amps out there (as listed in above threads) that will do an alright job. LT also published a design based on their LT1115 (IIRC) - you mught want to try googling that. Otherwise, Syn08 has some fine designs. Good luck.

[gaetan8888]

Originally Posted by tiefbassuebertr

Here the pdf schematic from this Musical Fidelity Preamplifier:

Hello

They use a similar ideas than the LM318 phono preamp with a LM394, but they use a NE5534 who are lower noise than the LM318.

Thank for this schematic.

Bye

Gaetan