Solid state phono preamp design philosophy

[mlloyd1]

pma:

understood. thx.

mlloyd1

 

[PMA]

Well, finally some small progress. The evaluation sample built, for MM. All discrete, JFETs + MOSFETs. Opamp for DC servo. Equivalent input noise 2nV/rtHz. Several measurements attached.

 

[mlloyd1]

interesting ... this sounds like a different design that what you initially described here for your MC opamp based design.
is this a product to be sold also or might you share more details?

mlloyd1

 

[PMA]

It is still undecided. First I would like to build a working prototype, the decision will be made after measurements and listening tests.

It will have sophisticated 3 stage power supply, with conventional series voltage stabilizer followed by CCS current source and by a shunt regulator. CCS and shunt regulator will be a part of the preamp PCB, series voltage stabilizer will have its own PCB.

Regards,

 

[Onvinyl]

It will have sophisticated 3 stage power supply, with conventional series voltage stabilizer followed by CCS current source and by a shunt regulator. CCS and shunt regulator will be a part of the preamp PCB, series voltage stabilizer will have its own PCB.

Close to my next phono project design, where I will use a CH-style source-follower and shunt regs.

Regarding discussing non-disclosed circuits -- not really my cup of tea, but your IP is your IP, of course.

Rüdiger

 

[PMA]

The power supply part might be disclosed, after the tests performed. My guess is end of January 2012.

 

[PMA]

This is the completed phono preamp:

 

[jacco vermeulen]

Pretty, but odd-looking input stage arrangement with the 92 Minis.

 

[PMA]

Odd minis, but genuine

 

[PMA]

Some measurements made, and a simple web page created.

Discrete preamplifier for MM cartridge

THD/SNR measured ref 5mV/1kHz input.

 

[Cobra2]

I would be interested in one...

Arne K

 

[mlloyd1]

PMA:

impressive curves. i guess i'm one of the few folks that admits to still using a mm cartridge.
btw, you must have a fairly substantial stash of the 2SK413/2SJ118 devices.


mlloyd1

 

[PMA]

In fact I will have to seek replacement parts soon, I have several tips that are still available.

 

[hags]

Pavel, do you have an update on this project?

 

[PMA]

Joe,

several units were produced and they are working and sounding well. But, for the reason of my very extended activities in the field of industrial automation I have to restrict my audio activities for the period of 1 year at least. So, no PCBs or modules for this project would be available now.

Best regards,
Pavel

 

[mr2racer]

Hello solid state! Just wanted to save this thread.

 

[PMA]

Okay, I will

 

[mlloyd1]

almost a week and no comments ...
amazing!

mlloyd1

 

[padamiecki]

almost a week and no comments ...
amazing!

mlloyd1

the people are soldering

 

[tiefbassuebertr]

Gentlemen,

I would like to open a discussion on this topic. MC phono preamp, solid-state.

- active/passive equalization
- discrete/opamp
- BJT/JFET, which position
- power supply, active PSU filter
- enclosure, shielding properties
- wiring, grounding
- SE/balanced

also of interest for the associated line head amplifier (Pre-Pre) of low output/low impedance moving coil cartridges is follow:
Which topology is the best?
Common base (low input impedance) or common emmiter/common source (high input impedance) ?
I prefer clearly the first mentioned (tested e. g. by Audio Technica ART1 (Art ONE), Ortofon Rohmann, several Lyras and AT-OC9 (all MK-versions).
In this case I start follow thread:
http://www.diyaudio.com/forums/anal...ges-mc-head-amps-common-base.html#post3120043