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.
Attachments
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
is this a product to be sold also or might you share more details?
mlloyd1
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,
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,
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
The power supply part might be disclosed, after the tests performed. My guess is end of January 2012.
Some measurements made, and a simple web page created.
Discrete preamplifier for MM cartridge
THD/SNR measured ref 5mV/1kHz input.
Discrete preamplifier for MM cartridge
THD/SNR measured ref 5mV/1kHz input.
Attachments
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
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
In fact I will have to seek replacement parts soon, I have several tips that are still available.
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
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
almost a week and no comments ...
amazing!
mlloyd1
the people are soldering😀
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
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