HPS 4.0 phono stage

[S.A.G.]

If balanced input is a concern it is probably best addressed with a transformer.

[syn08]

Originally Posted by S.A.G.

If balanced input is a concern it is probably best addressed with a transformer.

In every configuration you can think of, a transformer is the ideal low noise "amplifier". It happens that I don't like them, in particular for cost reasons

[PMA]

I wonder if you ever sleep, Ovidiu. Considering the time zone shift ..

[mos57]

Originally Posted by syn08

This is not for MM at all... The input current noise will significantly degrade the noise performance. OTOH, you don't need 0.28nV/rtHz for MM so there's really no incentive to build this phono stage.

If your preamp is suitable for MC heads moreover (low output impedance), then because you have configured the input stage as follower (hi-imp), indeed of a common base input stage (lo-imp)?

Francesco.

[Lumba Ogir]

Ciao,

If your preamp is suitable for MC heads

Not very suitable, but suitability is not a goal here...

[syn08]

Originally Posted by Lumba Ogir

Ciao,

Not very suitable, but suitability is not a goal here...

Thanks for the enlightening comment.

[S.A.G.]

In every configuration you can think of, a transformer is the ideal low noise "amplifier". It happens that I don't like them, in particular for cost reasons

Cost is surely an issue. Flexibility is another issue. A transformer for MC cartridge is a bandpass filter, the high pass cutoff frequency is usually located very close to the resonant peak of the cantilever / stylus damper system. Getting a linear frequency response from the transformer / cartridge system can be challenging.

[mos57]

Originally Posted by Lumba Ogir

Ciao,

Not very suitable, but suitability is not a goal here...

But if this preamp is not for MM neither for MC, anybody can explain me clearly for what other purpose?


Ciao a tutti, Francesco.

[S.A.G.]

Francesco,

The HPS designs are suitable for low output voltage and low output impedance MC cartridge.

[Lumba Ogir]

syn08,
I`ve seen your approach as a lesson in how not to design a MC amp. Just looking at it makes me feel bad. Since nothing is done right, discard the whole idea and start from scratch.

I`ve already suggested Hiraga`s design to you. I assure you, it would not be easy for anybody to come up with something better. No ugly ICs, grounded base input topology, simplicity. Battery supply is a must, otherwise talking about noise is pretty meaningless.