After bridge and 4m7 cap (no resistor no choke anywhere) there will be 180mV pk-pk ripple. Captured in the attachment.
That ripple feeds to the reg. After the reg, its a line. That capture was in hi-res mode in a deep memory scope. Which is a kind of boxcar averaging method to lower the noise floor.
In normal acquisition ghosts will appear riding the waves, same exact ghosts appear even when the power is off.
The scope's LCD refresh rate is under suspicion.Obviously very low source impedance to very high load impedance couplings when measuring from mOhm PSU to MegOhm scope and probe. What is real and what is ghost its not easy to tell in non optimized differential measurements for CMRR. Its surely common mode ghosting because its there either with the power on or off. So filtering can't be that bad for ease of mind against any gremlins, or to just let the reg work easier. Only if it does not end up sounding weird of course.
Attachments
When I did listen my noise on max volume of my pre-amp, FSP box was empty. No extra staff beside phono.
It maybe make sense to connect phono GND to its chassis and to run GND wire from PSU chassis in order to connect it to that point in FSP box too?
Its either due to ground or due to raw line imposing little something then. I don't think that we can ever have absolutely nothing than white noise background in non floating non balanced early from cartridge interface through balanced primary transformer for SE circuits, but you may try alternatives both for your grounding and your PSU filtering. Will do no bad.
This might take a bit more time. Received the SA1930 today but realized that BC337-25 was not on the order....Also ordered some Panasonic FR's for output caps
Output caps ?
They might well be one and the same, these days, Turbon.
Andy
FG ("Fine Gold") is a leaded cap, also called "Muse", and is just below KZ (also called "Muse"). Nichicon say that KZ is "higher grade" than FG, which is "higher grade" than FW. The KZ has slightly lower dissipation factor.
"Gold Tune" is a name they use for a range of snap-in caps, aka "KG". I think it's supposed to be their best "audio" snap-in capacitor. In fact KG is sold in 3 versions, Type-I and Type-II are called "Gold Tune", and Type-III is called "Super Through". The Type-III have gold plated terminals, and larger cases for the same capacitance/voltage, and lower DF and higher rated ripple current.
I have been listening to this for a few weeks. It sounds fantastic. Even in a mess of cables on my bench it is silent. The music was wonderful. Last weekend I changed C2Y to make tweaks to the tone. To my suprise my tin ears could hear the difference between 0, 100nF and 200nF. 100nF won. This gives me a total of 15.2nF for the C2 C2Y combination, measured with my probably not very accurate DMM. Your design and support, Teabag's organizing, work and bags of parts made this a very successful and easy build. Thanks to both of you.
Unfortunatly I have made no progress on the chassis. I spend the day at my workbench listening to vinyl. No thoughts of building the chassis, just music.
Thanks
Jim
Unfortunatly I have made no progress on the chassis. I spend the day at my workbench listening to vinyl. No thoughts of building the chassis, just music.
Thanks
Jim
You can tell. Its you use Lowthers. They got weak power response in the brilliance range.
I had a psychoacoustics seminar when I was 21. The organizer had a Masters diploma on the subject. He run some gong kind of frequency test on headphones we went through. Nobody heard beyond 15K on same level drive to 1K. He told us that the young can hear stronger to 20K but not before the drive is ten times higher. You don't lose frequencies, you lose sensitivity with age.
Capacitors the short story
I cheated. I used some music with harmonica. In one test the harmonica did not have quite enough edge to it, one was a tiny bit harsh, the middle was just right.
Capacitors the long explanation.
To get C2Y correct I changed one capacitor on a side and then listened with headphones to compare the tone directly. The leads from the turntable were switched twice to make sure the improvement was due to the capacitor. The album was Chicago: The Blues Today. My intention was to focus on Junior Wells and the harmonica to get the sound of his voice and the harmonica just right. It worked fine. I planned to use the same method with the Obligato Gold and Mundorf Supreme capacitors, but the capacitors had their own plan. At the beginning of the first side Junior gives a short introduction to the song. There was a bit of a rumble before the intro started. I changed out the Orange Drop (C3) for the Obbligato Gold. I could now hear that the faint rumble was a quiet voice. The new capacitor had made low level signals clearer. After changing the other side and a relisten it was now obvious that it was Junior's voice and that it was probably a taped earlier version that Junior was listening to on a monitor. It was set to run for a short while before Junior started, I assume he used this a prompt. Next I changed one of my Solen's (C4) out for the Mundorf Supreme. I could now determine the words from the faint monitor. After changing the second one I actually could hear an even fainter version leading this now clear version. Clearly the producor had taped an earlier version and used it as a prompt for Junior. That version was used and the result taped and then used as the prompt for the final version. It was amazing that these low level sounds were clear and distinct. Normally I would find this kind of thing technicaly interesting but not care that much as it is really the music I am listening to. As it turned out this improvement in low level detail improved the music. The voices and instruments became more distinct and the music sounded even more realistic. I could easily close my eyes and imagine I was in a smoky bar listening to a live band, a common occurance in my misbehaved youth.
Thanks
Jim
I cheated. I used some music with harmonica. In one test the harmonica did not have quite enough edge to it, one was a tiny bit harsh, the middle was just right.
Capacitors the long explanation.
To get C2Y correct I changed one capacitor on a side and then listened with headphones to compare the tone directly. The leads from the turntable were switched twice to make sure the improvement was due to the capacitor. The album was Chicago: The Blues Today. My intention was to focus on Junior Wells and the harmonica to get the sound of his voice and the harmonica just right. It worked fine. I planned to use the same method with the Obligato Gold and Mundorf Supreme capacitors, but the capacitors had their own plan. At the beginning of the first side Junior gives a short introduction to the song. There was a bit of a rumble before the intro started. I changed out the Orange Drop (C3) for the Obbligato Gold. I could now hear that the faint rumble was a quiet voice. The new capacitor had made low level signals clearer. After changing the other side and a relisten it was now obvious that it was Junior's voice and that it was probably a taped earlier version that Junior was listening to on a monitor. It was set to run for a short while before Junior started, I assume he used this a prompt. Next I changed one of my Solen's (C4) out for the Mundorf Supreme. I could now determine the words from the faint monitor. After changing the second one I actually could hear an even fainter version leading this now clear version. Clearly the producor had taped an earlier version and used it as a prompt for Junior. That version was used and the result taped and then used as the prompt for the final version. It was amazing that these low level sounds were clear and distinct. Normally I would find this kind of thing technicaly interesting but not care that much as it is really the music I am listening to. As it turned out this improvement in low level detail improved the music. The voices and instruments became more distinct and the music sounded even more realistic. I could easily close my eyes and imagine I was in a smoky bar listening to a live band, a common occurance in my misbehaved youth.
Thanks
Jim
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