replace digital filter SM5841AP for DF1704

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Hi Alenzo, do you have the data sheets? Both manufacturers have them online for download as pdfs. Then maybe you can see some of the pins you know what to do with, and some of them you need help with.

Ted
 
SM5841 pins

1-CKSL 18-DIN
2-XTI 17-BCKI
3-XTO 16-LRCI
4-CKO 15-BCKO
5-VSS 14-VDD
6-MDT 13-WCKO
7-MCK 12-DOL
8-MLE 11-DOR
9-RST 10-DG

DF1704 pins

1-DIN 28-LCRIN
2-BCKIN 27-SRO
3-I2S 26-BCKO
4-IWO 25-WCKO
5-IW1 24-DOL
6-XTI 23-DOR
7-XTO 22-VDD
8-VSS 21-NC
9-CLKO 20-OW1
10-MODE 19-OW0
11-MD/CKO 18-SF1
12-MC/LRIP 17-SF0
13-ML-RESRV 16-DEM
14-RST 15-MUTE

Due The Block diagrams and pins I will connect this

DF1704-> on place SM5841
6-XTI -> 2-XTI
7-XTO-> 3-XTO
9-CLKO -> 4-CKO
8-VSS -> 6-VSS
1-DIN -> 18-DIN
2-BCKI -> 17-BCKI
28-LRCI -> 16-LRCI
26-BCKO -> 15-BCKO
22-VDD -> 14-VDD
25-WCKO -> 13-WCKO
24-DOL -> 12-DOL
23-DOR -> 11-DOR

After this I must select Hardware control modes – this do it pin no.10 – MODE
10-MODE ->DGNG (VSS) position low
pins
3,4,5 - >DGND - data format 16bitMSB First
11 ->DGND – CLOCK as XTI
12-> DGND LRP
15-> DGND Mute ON
16-> DGND Deemphasis OFF
17,18 -> DNG sample rate for DEM 44.1kHz

19-> DNG
20-> VDD 20bit Data output
27-> switch DGND – VDD filtr slow – sharp


Is my procedure OK?
Is it correct when high position on pin is VDD-5V and low is DGND-VSS?
 

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alenzo said:

Is my procedure OK?
Is it correct when high position on pin is VDD-5V and low is DGND-VSS?

Yes, Vdd = +5V DC, Vss = DGND

The pin assignments seem OK but I haven't searched 100%. It is possible that some data timing differences may exist, I don't have experience of this conversion that you propose. Also check the DF1704 reset requirement, is it met by the capacitor on the 5840 OK?

Good Luck

Ted
 
I tried to do the similar replacement with SM5813APT but failed, It is strange that the sound seems good after replacement just at the moment of powering at, and it got worse till at last it seems nosie are playing. The 2560GL clock seems a little bit complicated.
 
SM5841B adds a DC offset (some 0.8%).
And it does a good job as an OS filter, I am not sure how much better DF1704 is, but check the output data formats.

PS: SM5845 and SM5848 are Denon proprietary filters, employing their first iteration of Alpha processing.
 
Denon DCD2560GL modified finished. Very good result.

1. recloking with a ext. TXCO.
2. change SM5841 to SM5842APT(Note: need to construct a convertion board Note: the and tone ajust function will be lost), and you must change the clock delay counter SM5828 to NPC upgraded version SM5839(?by memory, M/N need to be confirmed), and select correct jumper for its clock source from different pins of the clock shapper 74HC to make the clock arrived at AD1862 to be synced.

3. upgrade the I/V Resistor to high quality matched fours.

4. upgrad the AD1862 compensate cap.(1uf and 10uf) to high quality match fours.

step 1-4 get huge improvement!

5. add a 0.1uf decoupled cap to each opa. my selectio is black WIMA
6. upgrad the OPA stage, my selection is OPA627 I/V, OP2604 LPF, OPA627 buffer
step 5-6 should be fine tuned with differenct component to suit carious personal interesting in different sound style.

Note:

Try to modified the output coupling cap . But the sound change worser. Judged form the design, its seems to be determinded by the DENON engineer after fine tuning.

And try to upgrade the OPA of headphone output 4556 with high class OPA but fail. Be noticed that this OPA used for the headphone should be one with big current output capbility. It seems hard to find a better replacement, anybody have a good suggestion?

If any one interesting in this MOD, can mail me liuyuer@yahoo.com
 
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