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Joachim Gerhard Filter Buffer for ES9022

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#702
Hello Patrick,

Received the boards today. Thanks Mark, Patrick & Joachim.

Now I have some confusion regarding the BOM. This is the BOM I got from the thread.

4x 10R 0.5% SMD 0805 Digikey RR12Q10DCT-ND
2x 0R SMD 0603 Digikey P0.0GCT-ND
6x 100R 0.5% SMD 0603 Digikey RR08P100DCT-ND
2x 10k 0.5% SMD 0603 Digikey RR08P10.0KDCT-ND
2x 470R 0.5% SMD 0805 Digikey RR12P470DCT-ND

4x 220µF 25V Digikey P10271-ND
2x 150pF 16V PPS SMD 0603 Digikey PCF1461CT-ND

2x 18mH 5%, matched to 1% Mouser 434-02-183J

I understand that R2 and P1 from schematic are absent on the board. That leaves only R1, R3 and R4. R3 has been changed to 100R and also 2 additional gate stoppers of 100R have been added. I dont understand where 10R and 0R are used on the boards. I dont see them on schematic. Patrick, can you clarify?

Thanks
 
#703
Ignore my previous post, I got all the answers, I had missed the pdf Patrick had posted. Anyone building this and having the doubts I raised should look at Post #303 in this thread.

Thanks

baswamin said:
Hello Patrick,

Received the boards today. Thanks Mark, Patrick & Joachim.

Now I have some confusion regarding the BOM. This is the BOM I got from the thread.

4x 10R 0.5% SMD 0805 Digikey RR12Q10DCT-ND
2x 0R SMD 0603 Digikey P0.0GCT-ND
6x 100R 0.5% SMD 0603 Digikey RR08P100DCT-ND
2x 10k 0.5% SMD 0603 Digikey RR08P10.0KDCT-ND
2x 470R 0.5% SMD 0805 Digikey RR12P470DCT-ND

4x 220µF 25V Digikey P10271-ND
2x 150pF 16V PPS SMD 0603 Digikey PCF1461CT-ND

2x 18mH 5%, matched to 1% Mouser 434-02-183J

I understand that R2 and P1 from schematic are absent on the board. That leaves only R1, R3 and R4. R3 has been changed to 100R and also 2 additional gate stoppers of 100R have been added. I dont understand where 10R and 0R are used on the boards. I dont see them on schematic. Patrick, can you clarify?

Thanks
Click to expand...
 
#705
Hi to all member. I hope so to post it to the right place...

I have completed the board some time ago and the last days I have some measurements about this.
At first I am not familiar with this design and my theory electronic background isn't big.

I saw that this filter-buffer raise the upper acoustic frequencies from the 5KHz step by step with the almost 0.25dB at 24KHz and so up over the 50KHz.

Here is an ARTA capture with 96KHz sampling (it is from the headphone output of an EMU-0404 + buffer)

attachment.php


As I know, this filter designed from J.G for the 9022-9023 Sabre dac-chips. If I measured right by ARTA the output of 9023 (after the filter), the following capture demonstrate the comparison between the 9023 direct output via direct output + J.G filter/buffer (the black is from 9023 direct output). The AD captured done by analogue inputs of EMU-0404 (usb).
attachment.php


The upper raise of frequency response is clearly. I don't know if this is a choice by designer or not.
The same seems with the square wave of 20KHz.
Here, the output of Hameg generator was calibrated to 2Vrms (1KHz sinewave) and then a square wave achieved at the same level as before. The signal was driven to buffer input and the output of buffer was driven to oscilloscope for capturing through Pomona 50 Ohm resistor termination.
There is an overshooting, probably normal cause the upper lift of frequencies.
I observed that if the signal was closer to 2.87Vrms (with reference to 1KHz sinewave) the captured square was almost perfect.
attachment.php


Sorry for my english...I would like the opinion of more experienced members with this design.
 

Attachments

  • filter.png
    filter.png
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  • Comp_9023 direct output.png
    Comp_9023 direct output.png
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  • square_20KHz.png
    square_20KHz.png
    11.6 KB · Views: 1,295
Last edited:
#715
bkdog 2x
nopants 2x
misterrogers 1x
yoaudio 1x
RTD 1x
Stixx 2x
truepaul 1x
Bikeman 2x
PJN 2x
JJGB 2x
Bnorrish 2x
bcmbob 1x
Vegi71 1x EU
androa76 1X
rpafenberg 2X
suburra 1X
outriding 2x
Eric06 2x EU
Peja 1x
Djinn 1x

Running total 30
 
#716
bkdog 2x
nopants 2x
misterrogers 1x
yoaudio 1x
RTD 1x
Stixx 2x
truepaul 1x
Bikeman 2x
PJN 2x
JJGB 2x
Bnorrish 2x
bcmbob 1x
Vegi71 1x EU
androa76 1X
rpafenberg 2X
suburra 1X
outriding 2x
Eric06 2x EU
Peja 1x
Djinn 1x
Cobra2 1x

Running total 31
 
#717
bkdog 2x
nopants 2x
misterrogers 1x
yoaudio 1x
RTD 1x
Stixx 2x
truepaul 1x
Bikeman 2x
PJN 2x
JJGB 2x
Bnorrish 2x
bcmbob 1x
Vegi71 1x EU
androa76 1X
rpafenberg 2X
suburra 1X
outriding 2x
Eric06 2x EU
Peja 1x
Djinn 1x
Cobra2 1x
jayce996 1x

Running total 32
 
#718
bkdog 2x
nopants 2x
misterrogers 1x
yoaudio 1x
RTD 1x
Stixx 2x
truepaul 1x
Bikeman 2x
PJN 2x
JJGB 2x
Bnorrish 2x
bcmbob 1x
Vegi71 1x EU
androa76 1X
rpafenberg 2X
suburra 1X
outriding 2x
Eric06 2x EU
Peja 1x
Djinn 1x
Cobra2 1x
jayce996 1x
Fusion123

Running total 33
 
#719
bkdog 2x
nopants 2x
misterrogers 1x
yoaudio 1x
RTD 1x
Stixx 2x
truepaul 1x
Bikeman 2x
PJN 2x
JJGB 2x
Bnorrish 2x
bcmbob 1x
Vegi71 1x EU
androa76 1X
rpafenberg 2X
suburra 1X
outriding 2x
Eric06 2x EU
Peja 1x
Djinn 1x
Cobra2 1x
jayce996 1x
Fusion123
mepper 2x

Running total 35
 
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