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--- 3sourse:1dacs:es9018 [2020/03/18 09:28]
staudio [Отзывы]
+++ 3sourse:1dacs:es9018 [2020/03/22 02:12] (текущий)
staudio [Отзывы]
@@ Строка 5: / Строка 5: @@
 {{pdfjs>:3sourse:1dacs:es9012-9018.pdf}}
 ++++
+ES9018 + LL1674 и LL1684:\\
+https://www.diyaudio.com/forums/quanghao-audio-design/246579-super-converted-ll1684-6.html\\
+https://www.diyaudio.com/forums/twisted-pear/164294-buffalo-ii-transformers.html#post2139234\\
+https://www.diyaudio.com/forums/pc-based/302687-es9018k2m-es9028q2m-9038q2m-dsd-i2s-dac-hats-raspberry-pi-3.html#post5369598\\
 ==== Отзывы ====
+**Выход по току:**
+{{:3sourse:1dacs:9018-1674.png?400|}}
+{{:3sourse:1dacs:iv-9018.jpeg|}}
+The 47nf cap creates a corner 3db point of 23K without the preamp secondary impedance reflected to the primaries and 20K with it reflected. But that is not the reason why I have the cap. I discovered the effect of a cap across the legs on sigma delta DACs nearly 3 years ago by accident. I reported in the these posts
+Practical Implementations of Alternative Post-DAC Filtering
+That thread was started by a member who also noticed the same effect. He unfortunately got flamed for reporting it without adequate explanation. The effect is that is creates is a layering of instruments that makes listening to music - emotional.
+The oldest reference I can find to this effect is here
+http://www.raylectronics.nl/pdfs/Mau...6367_tweak.pdf
+Regarding the transformers - yes LL1544A is amorphous too. Nearly $85 in the US vs LL1674 which is $130
+The resistor value to be chosen depends on your taste. Put simply - the deeper you put the DAC into current mode (by lowering the resistor) - the THD improves. At 0 ohms - the THD is the best.
+But in all honestly - I can*t hear THD in my system below -105db.
+But I what I can hear is that the slam/attack/dynamics are lost deeper in the current mode.
+The optimal value for the resistor is 4/5 times the output impedance of the DAC for my system. So 640 ohms for ES9028Q2M.
+I thought so too initially that there was the HF explanation but there is some other mystery to be solved as well. Specifically - if you ground the caps, the effect is gone. In other words if you replace the 47nf across the pins with 94nf to the ground from each leg - the layering of instruments and the emotional connection is lost.
+Also - if you vary the 3db corner - i.e. move it to say 30Khz - the effect is gone. It only seems to near the 20-22Khz region. I settled on 19.9 corner for my system.\\
+https://www.diyaudio.com/forums/pc-based/302687-es9018k2m-es9028q2m-9038q2m-dsd-i2s-dac-hats-raspberry-pi-post5370639.html\\
+----
+**Выход по напряжению:**
 Just a quick query because I can't seem to find anything but simple 2-page PDF datasheets for ESS DAC chips...
@@ Строка 15: / Строка 58: @@
 ----
 In short, yes. ES9018 and its derivatives can support voltage mode or current mode. It depends on the input impedance where the next stage has. When it sees a low impedance, it's current mode. ES9023 has integrated amp for voltage out. I don't know if it can support current output.
-----ES9018 has some DC offset voltage on the output, so you need something to get rid of the DC before sending it to your amp. It makes about 3Vpp with a few mA of current if you parallel 4+4 channels for stereo. It sounds pretty good with just a transformer, but bass is lacking and mids not full bodied compared to Twisted Pear Buffalo32 with IC i/v stage. I sometimes wished for more than 1.5 V output, but it was usually enough.
+----
+ES9018 has some DC offset voltage on the output, so you need something to get rid of the DC before sending it to your amp. It makes about 3Vpp with a few mA of current if you parallel 4+4 channels for stereo. It sounds pretty good with just a transformer, but bass is lacking and mids not full bodied compared to Twisted Pear Buffalo32 with IC i/v stage. I sometimes wished for more than 1.5 V output, but it was usually enough.
 You can get the 9018 technical specsheet if you sign nondisclosure form.

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