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Joachim Gerhard Filter Buffer for ES9022

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#521
I suggest you take a closer look at how I did the ES9022, as different from others.
Pictures of both sides of the PCB have been published, so it is not difficult to see.

http://www.diyaudio.com/forums/digi...ng-new-ess-vout-dac-es9022-2.html#post2458181

And you can try to mock up what I did with some SOIC16 adaptor boards, and a lot of P2P in air.

The same circuit done with different layout and different choice of components can sound totally different.
One of the guys who have my 9022 will testify to that, as he has heard two versions of 9022 done differently, with totally different results.


Patrick
 
Last edited:
#522
question about filter

Patrick,
I just put together another ES9023 DAC (Subbu / JP board + their PS) and one of the JG filters from the group buy. It's still burning in but after running all night, it sounds quite promising. Thanks again for making the boards available.

I did have a question about the design. I notice that there are some small 10 ohm resistors at the power supply input - R7 and R8. Could you comment on the benefit of these vs. hooking up the filter directly to a well regulated power supply?

Thanks,
---Gary
 

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#528
Output voltage swing is about +/-3V.
Cascode voltage for the BF862 (Vds) is about 5V. Idss for the BF862 is 12~25mA.
The J111/J174 can take max 30V Vds, but dissipation is limited to around 250mW.
At below 5V Vds, capacitances for JFETs becomes too non-linear.

So you now have all information needed to calculate max/min rail voltages. 🙂
BTW all the above info can also be found in standard datasheets.


Patrick
 
#530
EUVL said:
They help to isolate the left & right channel.
You can try to use 0R resistor or even wire jumper to see what you like better.
Click to expand...

Patrick,
I did the experiment of replacing the 10ohm resistors with wire jumpers and in my system, I think it's an improvement. It feels like the low end is a bit less confused in complex passages and the overall "ease of listening" improved somewhat. I think I'll keep it this way for a while.

---Gary
 
#535
I don't know much about audiophile battery technology, I keep a few of a type similar to the below link, around for LED Bike lighting:

3800mAh DC 12V Super Rechargeable Lithium ion Battery Energy Storage Pack | eBay

if one made a harness to reverse polarity on one of the feeds {not the battery harness, an intermediate harness to flip one source}... Then does one also need to NUL the circuit for any differences in the packs? Of course they both sag as they wear off the "just charged" "high". Pardon me for not having the schematic in front of me. I will be using mains power and regulators, just trying to help brain-storm the obvious questions.
 
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