replace digital filter SM5841AP for DF1704

[alenzo]

Please I would like replace SM5841AP (SM5840) for DF1704 in my CD player Denon DCD 2560. Can you help which pins I can use and adjust for DF1704?

Thank you very much.

[tedr]

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

[alenzo]

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?

[rfbrw]

And the input and output formats ?

[alenzo]

Input data

standart sony 16bit MSB

Output data

20 bit MSB first

[tedr]

Originally posted by alenzo

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

[liuyuer]

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.

[ruteksen]

I have the same in my CD but DCD-655 where originally was SM5841BS. In software mode there was a music but with a lot of noise and what's more in hardware mode there was no sound. Maybe somebody know what is wrong?

[SoNic_real_one]

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.

[ruteksen]

Finally at the end I started the DF1704 and if someone needed help write to me ruteksen@o2.pl I will try to help. DF1704 is better than SM5841BS but i'm not shure if it is worth the price of DF.