TDA1541A non/os harsh!!!

[mikeliu]

Denon DCD S10 (2 AD8620, 4 opa627BP, 8 opa637BP, Elso kwak clock 6)
Rotel 855 (non/os, 2 AD8620 ,Elso kwak 7)
Magnavox CD650(non/os, 2 AD8620, TDA1541A S1)
When I listen some violin CD, I fell the Rotel 855 and Magnavox CD650 are sweeter than the Denon DCD S10, but listen femal voice the Denon DCD S10 is less harsh than the Rotel 855 and Magnavox CD650. Will the TDA1543 nos/os be less harsh than TDA1541A nos/os?

[jean-paul]

Did you change the analog filter when you made the cdplayer non os ?

[mikeliu]

I just changed the two NE5532s on non/os Rotel 855 and Magnavox CD650. Should I build a new I/V stage?

[Guido Tent]

Originally posted by mikeliu
I just changed the two NE5532s on non/os Rotel 855 and Magnavox CD650. Should I build a new I/V stage?

I'd reconsider a new analog filter

regards

[jean-paul]

When you make a TDA15xx cdplayer non os the analog filter has to be recalculated. Use the Search function for more info, there are threads about the subject. The harshness comes very likely from the unchanged filters, it has nothing to do with the used chip.

When you're brave please listen to the cdplayers once without analog filtering. So use the opamps but remove filter components. When the harshness is gone you have an indication you're on the right path.

Warning: I wouldn't recommend to listen without analog filtering permanently. There could be ( there are in fact ) some RF components in the output signal that might disturb your amp. That being said I can tell I use only 6 dB/oct filtering with TDA1543 non os DAC's and I get away with it. Although I haven't built it, the discrete outputstage Rbroer designed looks promising and it is simple to build. Should be better than a opamp stage anyway.

[Elso Kwak]

Originally posted by jean-paul
That being said I can tell I use only 6 dB/oct filtering with TDA1543 non os DAC's and I get away with it. Although I haven't built it, the discrete outputstage Rbroer designed looks promising and it is simple to build. Should be better than a opamp stage anyway.

Hi Jean-Paul,
What is the crossoverpoint (-3dB) of your 6dB/octave filter?

[Peter Daniel]

Originally posted by jean-paul
That being said I can tell I use only 6 dB/oct filtering with TDA1543 non os DAC's and I get away with it. Although I haven't built it, the discrete outputstage Rbroer designed looks promising and it is simple to build. Should be better than a opamp stage anyway.

That's being said, I'm perfectly happy without any filtering at all in my NOS TDA1543 DAC. There is no sign of harshness or fatiguing or irritation, totally smooth highs.

[Elso Kwak]

Originally posted by mikeliu
Denon DCD S10 (2 AD8620, 4 opa627BP, 8 opa637BP, Elso kwak clock 6)
Rotel 855 (non/os, 2 AD8620 ,Elso kwak 7)
Magnavox CD650(non/os, 2 AD8620, TDA1541A S1)
When I listen some violin CD, I fell the Rotel 855 and Magnavox CD650 are sweeter than the Denon DCD S10, but listen femal voice the Denon DCD S10 is less harsh than the Rotel 855 and Magnavox CD650. Will the TDA1543 nos/os be less harsh than TDA1541A nos/os?

Hi Mikeliu,
I was never able to elicit any harsh sounds from the TDA1541! In fact I found it too mellow, "polite", uninvolving....
The TDA1541 does not sound harsh, NON-OS, in my Phlips CD-650 with orginal analog filtering still implemented, that is for oversampling.
If you find the TDA1541 harsh you will find the TDA1543 unbearable.......
I am not familiar with the AD8620 yet. May I suggest using the OPA2604 instead? Especially as a IV-converter it can't be beaten I think. I tried a lot of IC's !
Just a thought:
You did lower the supply voltage to +/- 12V for the AD8620 in these players?

[jean-paul]

I am not familiar with the AD8620 yet. May I suggest using the OPA2604 instead? Especially as a IV-converter it can't be beaten I think. I tried a lot of IC's !

Then you should try AD8620 I think. Please don't suggest other chips when you don't know the used type. Leave it where it is Mikeliu, AD8620 is very good.

Just a thought:
You did lower the supply voltage to +/- 12V for the AD8620 in these players?

Very good point as most cdplayers use +/- 15 V which is too much for AD8620. I assume you did correct the supply voltages otherwise you probably have the main reason for the nasty sound. Nevertheless I think it is better to recalculate the analog filter ( or leave it out when you like to live dangerous ).

Elso, one DAC has a filter with -3 dB at 48 kHz just to prevent very high frequencies from going in my amp. Never bothered to implement sinx/x filtering. I don't have any problem with the high roll off.

To be honest, most of my TDA1543 dac's didn't have filtering at all. Maybe I put 2 caps at the output of that series just for peace of mind

[Elso Kwak]

Originally posted by jean-paul


Then you should try AD8620 I think. Don't suggest other chips when you don't know the used type. Leave it where it is Mikeliu.

Jean-Paul,
I suggest the chip I have very good results with