Simplistic NJFET RIAA

Well... couldn't quite wait for full finishing... Tad hair-raising making sure the power cable and FSP PSU were oriented correctly. "Make no catastrophic polarity mistake" from the FSP build guide ringing in my head! :eek: (I am making a dedicated PSU for Ultra, hence a slight re-tweak of T.P for the FSP PSU).

For whatever reason the Ultra is quieter in my already quiet system even without lid etc.? Interesting. Gut impressions are YES! Sounds fantastic. MORE OF EVERYTHING. It's possible that I'm liking the 220R loading vs 100R/SUT loading on FSP with Hana ML (they recommend 100R)—as an aside the Denon instructions for the 103 address SUT vs. not, they recommend 40R for SUT and 100R for non-SUT. Also have 220 Wima in for treble trim—not sure the value of the poly from FSP? That recording is a "worst case scenario" record—sounds the best I've heard it so far—I think the piano is out a bit—it's a reissue, and I have an original that does sound better but needs a cleaning...

Ultra is keeper!!!! —more impressions later of course! Need some time with it... I'll do as close to an A/B as possible with DL-103, HanaML, AT33PTG/2 and various loadings on Ultra—will likely add some sockets to FSP for loading options in SUT mode.

Salas and Tea—THANKS!!!!!!! You are a gift to this community.

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diyAudio Chief Moderator
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Since everything works and all is quiet your build is obviously a success. You will surely discover your best liked input loading & C2Y HF tuning details. The SP-10 on heavy layered plinth with the Jelco and the Hana is a showcase of Japanese analog cool. Alphaville's Big In Japan should play great on it. :D
 
diyAudio Chief Moderator
Joined 2002
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For whatever reason the Ultra is quieter in my already quiet system even without lid etc.?

Beyond there's no SUT now (helping with hum if balanced input impedance but has some winding resistance noise, nothing is noiseless) maybe you grounded the system differently in a way your TT likes better? I see an insulator on the chassis ground lug for instance. UFSP PCB already has carefully placed substantial copper shields and diligent layout but is that chassis also put at signal ground level in some way?

In any case (pun intended) keep the wiring scheme your system likes best for performing at its most quiet.
 
OMG—didn't even notice the crazy homage to Japanese analog cool! Happened quite organically. Alphaville :nod:. Haha.

Salas—you are awesomely observant. I had just posed that question to 6L6 regarding my FSP build—which doesn't have an insulated grounding plug. This is one of those case by case things? Honestly it wasn't with intention on my part—but I love that it happened. Perhaps I will try that on FSP when I add some sockets. Signal ground is only going to board? But maybe I'm not understanding:
...but is that chassis also signal grounded in some way?


Sigur Ros at high volumes is quite great test material...BLISS!
 
diyAudio Chief Moderator
Joined 2002
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FSP and UFSP boards are of different design plus you have a SUT and MM/MC switch wiring on your FSP so I can't tell what to prefer best in your system but in general a non insulated lug places the chassis at same potential as the circuit's zero level. Since having it already insulated in your new case you can simply test with a crock lead from it to the chassis for what is best in your system.
 
diyAudio Chief Moderator
Joined 2002
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Signal ground is only going to board? But maybe I'm not understanding:

TT ground wire goes to the channels boards through the lug with your yellow cables. Then through the power umbilical return lines goes to the Raw PSU zero points and to its chassis reference there. If zero is not wired to the main chassis in some other way, a non insulated lug would be the contact point that brings the main chassis to zero level.
 
diyAudio Chief Moderator
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Got it! Will try... And we are talking SMALL amounts of "noise" here. Small enough that it's probably a non-issue for normal in-the-house listening...

Maybe nothing will change to even better noise wise but its good to have the main chassis referenced to zero. Try with a test lead and if not to the worse, ground it permanently.
 
Okay—that might have confused me a bit (#18293). I just connected a lead from grounding lug to case on Ultra—an almost imperceptible rise in noise. So it's a small tad better with ground lug isolated (SMALL). There's no ground connection per se in the form of a wire connecting ground (boards or chassis) between UFSP and RAW PSU. The cable I made has the shield/ground connected only to PSU end connector (which then goes to chassis—not RAW—inside the PSU chassis). This was per what I understood from the FSP build guide.
 
OH MAN!

LOVE THIS PRE. Not sure how it was possible for improvement Salas, but it's there.

Messing around with loading on the Hana. Feeling the 100R over the 220R. Can't be more specific, it's an instinct thing... More refined subtleties? IDK.

Chassis done—starry night lid. With dry erase capable gloss front—and one for you Salas! Hopefully that is the right cultural sentiment? I blame Google translate if not. "Blissout" is already slang-ish in English... tried to get close? :D

Proper biasing really does need the lid. I found that I needed to nurse it a bit over time, and had a pretty short window of opportunity to adjust once the lid was off—before measurements started floating around...Best phono pre on the planet? I feel lucky to get to own this and use it daily. Next up may be another plinth for a 12" arm at the back... and FSP. Still have to make a PSU for Ultra—waiting on parts...

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