Resistor upgrade on digital board

Hello!
Which of the following resistors suitable for the upgrade of digital section of DAC or CD player? Not for I/v stage.

1) Caddock MK132
2) Takman metal film
3) Vishay naked TX2575

Which one improved the microdynamics?

Thanks in advanced!
 
Digital, hard to say, pretty blanket request really.
Usually the lower inductance parts will excel, but hard to say without any knowledge of the particular circuit.

Probably better to leave the digital part alone, and use the analog output portions to meddle with the sound. If you want crazy detail, try Elna Cerafine capacitors in the power supply for the op amps…
 
It’s the analog part where resistors make an audible difference. A digital signal is either on or off no shades of gray. As long as the digital parts are matched you should be good. Noise specs are important for the I/V and further stages. It would be hard to find a modern resistor that was so noisy it screwed up the digital signal!
 
Haven't done any experiments with phase noise and resistors. Therefore no particular personal opinion on it. Maybe different opinions for some other passives though which is why I brought up the issue of considering some RF as analog.
 
I made a comment on the post I quoted nothing more. Its not always just ones and zeros when data conversion is involved. Timing of samples is an analog issue that people sometimes tend to overlook, or presume is merely digital. My comment was in regard to that presumption.
 
Of which you have nothing to substantiate about. This is called FUD spreading, your favourite MOP.

There is absolutely no correlation between the resistors in the digital section and any sound quality metric. Spending money on expensive resistors there is foolish, to put it mildly.
 
I have experimented on analogue out boards of digital units and preferred Takman Rey over Rex, I did actually find the annoyingly expensive Shinkoh better than Takman Rey and didn't like toleranced Allen Bradleys in the signal path a safe and cheap option is Takman, If they are through the board and not SMD then worth experimenting. Personally I'd start with Takman Rey

Regarding dynmamics the Reys are very good, the Shinkoh add a little more reality somehow and more scale. Both take some time to burn in (I await the flack, but this is my experience)

Definitely more audible changes with capacitor alternatives
 
And the relationship between the clock phase noise and the resistors in the digital section is…?

One or a few of the resistors might be series termination resistors for clock signals. You would typically have a driving circuit, resistor, PCB trace that acts as a transmission line and some receiving circuit of which the input section more or less acts as a slicer that compares the momentary voltage with a logic threshold.

Suppose you put a voltage step from 0 to V with a rise time tr (waveform consisting of straight line segments assumed for simplicity) into a series termination resistor with resistance Rt driving a transmission line with a characteristic impedance Z0, delay greater than or equal to tr/2 and open end. Initially you will then get a voltage at the line that rises from 0 to V Z0/(Rt + Z0) in a time tr, but the reflection at the end will make the voltage double, so at the end of the line you see a voltage increase from 0 to 2 V Z0/(Rt + Z0) in a time tr.

Clearly, the time it takes until the voltage crosses the logic threshold Vth with 0 < Vth < 2 V Z0/(Rt + Z0) will depend on the series termination resistance Rt. A resistor with 1/f noise has slow random variations in resistance, which will therefore cause close-in phase noise at the output of the slicer.

I see three ways to deal with this:


1. Look up 1/f noise data for thick film resistors and do a back-of-an-envelope calculation to see how much impact this has on the reproduced audio. Chances are that the effect will turn out to be completely negligible, but as I haven't done such a calculation, that is an unsubstantiated claim that should result in serious criticism from syn08.

2. Do measurements using various kinds of resistors.

3. Just use a thin-film SMD resistor, like Mark recommended, knowing they have only little 1/f noise. Some types of thin film SMD resistors cost only euro 0.09 in small quantities, so chances are that this is cheaper than the envelope needed for option 1.


To me all three methods seem perfectly reasonable.