As mentioned before the digital roll-off in small increments is trivial to achieve with a single biquad filter if anyone just wants to listen to that without the analog modification.
To clarify this comment, I would gladly provide the filter coefficients for Audacity which is freely available so anyone could do the test digital filter only. I won't bother if no one is interested.
I thought the point was that EQ before the DAC does not have the same audible effect.
Or am I missing something?
Or am I missing something?
Morning 🙂
I'm using a heavily tweaked pcb with CS4398 dac.
I was earlier in this thread told to use this scenario:
BUT... Is it in any way possible to avoid transformere for achieving this effekt with the CS4398 dac???
I feel I have been through transformers before with ES9018 and Lundahl LL1684 1:1 Amorph! And with several different filters after..
For my ears - Sound is better with dac output directly through a Jensen copperfoil cap and into the grid of my low gain tubes!!
So again - can this effect be achieved without the transformer only resistors and caps?? With CS4398? 🙂 I hope so!
Best from
Vingborg
I'm using a heavily tweaked pcb with CS4398 dac.
I was earlier in this thread told to use this scenario:
Scenario Four:
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The key is the Zobel Network. The "R" 1K5 and "C" 15nF are only a possible example of values.
The goal here is to adjust those "RC" values and achieve a 1st Order filter response by use of an "over-cooked" Zobel network.
BUT... Is it in any way possible to avoid transformere for achieving this effekt with the CS4398 dac???
I feel I have been through transformers before with ES9018 and Lundahl LL1684 1:1 Amorph! And with several different filters after..
For my ears - Sound is better with dac output directly through a Jensen copperfoil cap and into the grid of my low gain tubes!!
So again - can this effect be achieved without the transformer only resistors and caps?? With CS4398? 🙂 I hope so!
Best from
Vingborg
I thought the point was that EQ before the DAC does not have the same audible effect.
Or am I missing something?
If i understood it right, the point is to get targeted response at the dac's output. It's not about the final freq response which can be even eqed back to flat if one desires. So, digital domaine eq should work?
If i understood it right, the point is to get targeted response at the dac's output. It's not about the final freq response which can be even eqed back to flat if one desires. So, digital domaine eq should work?
Yes. The setting if using JRiver are shown in Post #6 and there are likely other ways to do it. But this is 64 bit, nice.
Morning 🙂
I'm using a heavily tweaked pcb with CS4398 dac.
I was earlier in this thread told to use this scenario:
BUT... Is it in any way possible to avoid transformers for achieving this effect with the CS4398 dac???
Sure, but you need a circuit that can sum the phases. The beauty is that 1:1 transformers work so well for CS4397/4398 and does the summing of the phases.
BTW, and I actually have done this, with 1:1 transformer tapping straight on to the two phases, leave the other post-DAC circuit in place, don't even disconnect it. Run the transformer as well and have two sets of outputs. The other interesting thing, quite curious, since the post-DAC filter is the Zobel network on the secondary and affecting the DAC from there, then you more regular circuit should also show some benefit. So I would hook the Lundahl 1:1 transformers in there and go for it. Next get a Zobel working, that is the trickier part. You can do this to "voltage" DACs only.
Mooly, did you try experimentally determining the frequency response? That seems like a logical first step, but of course, there's no reference measurement from Joe to compare it to... at least you can see if there's any gross errors introduced by the "mod."
Nothing drastic showed up when tested with a red book CD at spot frequencies out to 20kHz. I would like to check again though that the un-modified player really does have that slight hf rise that the simulation shows as I'm fairly certain that I have not observed that effect before.
I thought the point was that EQ before the DAC does not have the same audible effect.
Or am I missing something?
My understanding (and intent of inquiry) is that we would like to separate the response shaping from any digital hash filtering.
I.e. is the claimed sound change primarily from the fact that the highs are slightly recessed or is it a result of removing aliasing/hash?
A simple 1st order digital effect in audacity should do well to test the first part.
Looks like we may have restarted well.
May I point out something in the way of a clue, a common denominator and probably most surprising: That this works across the brands of DACs like Burr-Brown and ESS, Cirrus Logic and so on, why should they react to that particular shape, which is another way of saying, applying something of a load on the DAC where something starts to happen around -1dB and finishes by -1.5dB -what is the mechanism they all have in common?
That is more surprising to me than anything else. But THAT has to be a very strong clue. Find that and I think we may have the answer, it is in the commonality of those DACs behaving the same.
I thought the point was that EQ before the DAC does not have the same audible effect.
Or am I missing something?
No, not missing anything. Yes, that was the point from the start.
With the signal out 1uF cap fitted, how essential to the subjective improvement is the supply shunt 20uF ceramic//0.33F supercap combination ?.
Dan.
Dan.
I thought the point was that EQ before the DAC does not have the same audible effect.
Or am I missing something?
That's the assertion, yes, but Joe has provided no data to support that claim.
Yes, we know this already.That's the assertion, yes, but Joe has provided no data to support that claim.
Measurement progress is on it's way.
Dan.
Yes, we know this already.
Measurement progress is on it's way.
Dan.
There would be no real progress without db listening test.
Let`s taking it step by step... There may not be any hurry in all this... The progress is however ongoing...
Let's leave all of these kinds of commentary alone for now.There would be no real progress without db listening test.
I expect that Joe's schematic changes are likely to cause some kind of subjective difference, however slight the audibility.
The subject here is to gain insight/measurement into the changes wrought, and technical explanation.
Dan.
If i understood it right, the point is to get targeted response at the dac's output. It's not about the final freq response which can be even eqed back to flat if one desires. So, digital domaine eq should work?
Yes, you could try either way. The restoration of flatness could be done first and one could see if the mojo is lost.
The subject here is to gain insight/measurement into the changes wrought, and technical explanation.
Dan.
Just a pre-warning, IMO observing any other DAC behavior changing dramatically simply tuning the effect from -.5dB to -1.5dB is highly unlikely. I also wish the jitter stuff was off the table it will make this a mess since the reasoning is very unsound.
BTW Max someone was kind enough to get me the wafers, I just need to figure out how to pack them for the trip.
That's the assertion, yes, but Joe has provided no data to support that claim.
Depends on how you define data. Yes, I actually do see your point (and that it is a reaction to 'bad science' because there is a lot of that around), but I am also less inflexible. You know, there are actually people who trust my ears and I trust theirs. And I am actually very cautious when expressing what I hear - something that may surprise some here. And while not using DBT, which we don't need to rehash, there are other types of tests where the listener is not even aware there was an A-B-C. This means no impairment of judgment. He reacts normally under that kind of test. It is a more recent method and one I think has significant advantages.
I just think this is an area that we should agree to disagree - and agree not be disagreeable.
It's a free world where we have the right to form our own opinions based on our own experiences. Doesn't mean mine is more or less valid than yours, just different. And I don't even mind discussing those differences, but it must be done with a respect that works both ways.
As I said before, I can stop anybody doing any tests on their own.
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