So what. Many people have different opinion on this and yours (or the opinion the number of people you refer to hold) is not a superior opinion. I have both SE and balanced dacs and amps. Tube and solid state. I don't see why dac should be anything but transparent as I don't listen to the dac directly but through amps and speakers/headphones which have a sound of their own.
Hi Mark,
You don’t have to clarify anything at all.
Just use what sounds best to your ears.
I only have a problem as explained with the generalisation that SE sounds better, just because it is no defined state.
Look at the CMRR in Marcel’s Dac that worked over the whole audio range, you resticted that to DC, but you are stil using the same SE output, see what I mean?
As a matter of fact you made an interesting alteration that changed the sound for the better.
Keep going on with alterations and telling us what you prefer.
Hans
On the subject of whether SE or balanced/differentially-summed dac sound better, I ask people to listen. When I say some people have found SE to be superior in terms of reproducing more low level musical details but the details are NDA, the only reason I'm telling you about that at all is to give a reason to bother with listening for yourself and then form your own opinion.
I've now been living with the FIRDAC for a few days with the passive filters connected to both of the DAC outputs and then through Lundahl LL1588 transformers. To be fair, the components are budget and the lashup wiring is not pretty, however I am more than happy enough with the sound quality to have ordered a pcb and better components to take it further. I am going to build a "drop-in" pcb to fit in place of the filter pcb so that it will be easier to make more tests and comparisons.
I honestly prefer the sound using both outputs from the DAC core over one side. The imaging is amazing and the low level detail is the best I've yet had. I can say I am very, very pleased. Definitely into diminishing returns territory for me.
I honestly prefer the sound using both outputs from the DAC core over one side. The imaging is amazing and the low level detail is the best I've yet had. I can say I am very, very pleased. Definitely into diminishing returns territory for me.
Okay. That's one vote, thank you.
On my system, Andrea's dac is still superior hands down. That's using passive filtering including transformers.
Also on this system and IMHO, Marcel's dac with passive filtering of the non-inverting phases is better than Marcel's dac with the filter board, regardless of the filter board configuration. This is in terms of reproducing more low level musical details with less blurred sound. Distortion and or noise are separate issues for me at this point.
Interesting thing was that Marcel's dac in its original form, with clean power and clocked by I2SoverUSB, had a certain charm to the sound that hinted at a lot of promise. So far though as I drill down deeper I am finding it tends to sound more like similar RTZ FIRDAC dacs at this particular stage of development. If there is no interest in optimizing the filter board for fully SE operation, probably best to set the filter board aside and continue with the adapter assembly shown below.
On my system, Andrea's dac is still superior hands down. That's using passive filtering including transformers.
Also on this system and IMHO, Marcel's dac with passive filtering of the non-inverting phases is better than Marcel's dac with the filter board, regardless of the filter board configuration. This is in terms of reproducing more low level musical details with less blurred sound. Distortion and or noise are separate issues for me at this point.
Interesting thing was that Marcel's dac in its original form, with clean power and clocked by I2SoverUSB, had a certain charm to the sound that hinted at a lot of promise. So far though as I drill down deeper I am finding it tends to sound more like similar RTZ FIRDAC dacs at this particular stage of development. If there is no interest in optimizing the filter board for fully SE operation, probably best to set the filter board aside and continue with the adapter assembly shown below.
Mark,
Where did you get the impression that nobody is interested in further development of the filter board to your own taste.
I think that would be a mistake, at least I am highly interested.
One question, you mentioned that Marcel’s Firdac originally had a certain charm, but that it now sounds more like other RTZ Firdacs, right?
Was this before or after you changed the CM rejection opamp from very wide to very small ?
You are using now as I understand the positive side for your SE connection, would it be possible to also try the negative output for SE and listen whether the sound is still the same or not ?
Hans
The first change that disturbed the charm was the clocking change (which occured before doing the filter board reversible slow-down mod). I have heard of euphonic jitter before, could be that I2SoverUSB has some of that. Should know more when the parts arrive from Italy and digital input cables can become very short, galvanically isolated, and reclocked.
Sure, its possible to modify the adapter. However, I know it will sound different on my system unless I invert my amplifier or speaker phase too. I could do that by swapping the transformer secondary leads. Otherwise sounds like kick drums don't punch out, they suck in, which just sounds different. The ESL panels have a semi-figure 8 pattern so the punch will come out the back and reverberate around behind the speakers. The room reaction sounds different.
That said, I have tried what you are talking about with Andrea's balanced DSD dac already. There was essentially no difference in sound if speaker phase was reversed too.
It's off topic, but what kind of filter inductors are used? I use fairly large N48 potcores with airgaps in my valve DAC, because the standard inductors almost never have their distortion specified. The only signal transformers in my valve DAC are used to make the output compatible with both differential and single-ended inputs.
The transformer has limited bandwidth and is lossy at HF/RF. The electrolytic DC blocking cap is lossy at HF/RF. The long cable may look like approximately like a capacitor at audio frequencies, but at HF/RF if looks more like a distributed filter and or mismatched, nonuniform transmission line. The devices that are lossy may be thought of performing some function like ferrites are sometimes used for. There are no physically lumped inductors at this time, although I would like to include some and I know exactly who I would want to have custom make them. At moment I don't have pull to make it happen, so I'm living with what I can do with available components.
Also, PM sent.
Also, PM sent.
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and Marcel’s FIRDAC has differential processing at the output stage. Looks great to me and sounded great to others.
Andrea’s one is BALANCED only, no differential effects, two independent halves of switched resistor arrays with mismatches ‘smearing and blurring’ the output, as you put it.
Andrea’s one is BALANCED only, no differential effects, two independent halves of switched resistor arrays with mismatches ‘smearing and blurring’ the output, as you put it.
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People only know the best they have heard. Marcel's dac can have a certain 'charm.' How many have heard Andrea's dac at its full potential? Just me?
No. Have you read the user manual? Andrea's dac can be used differential or SE. The manual shows how to hook it up either way.
The smearing and blurring as I described is in regard to the output sound of Marcel's filter board is a product of many factors. What something sounds like often depends on the specific implementation more than the general topology. Never said anything here about Andrea's dac smearing and blurring because it didn't. However, it did sound better in SE mode, and his next DSD dac will be SE only. Please try not to jump to conclusions about such things if possible. Better to just ask if you aren't sure.
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I find I get to illicit answers and understanding better by winging it with these type of posts. Please don’t take it any other way. Others have seen something similar. Maybe that’s how my brain works.
Ok, back to the topic, as I see it both types of FIRDACs start off with independent BAL digital processing using two halves of switched resistor array. This is somewhat flawed as you explained before about mismatches that cause ‘imbalances’ in a balanced system - nothing like this in a pure SE processing like e.g. re: Signalyst DSC1
We have seen how Marcel output stage looks and works.
How, is the SE output of Andrea’s diy version configured, say if I want to use an electronically coupled Amp ( no trafos pls)
Ok, back to the topic, as I see it both types of FIRDACs start off with independent BAL digital processing using two halves of switched resistor array. This is somewhat flawed as you explained before about mismatches that cause ‘imbalances’ in a balanced system - nothing like this in a pure SE processing like e.g. re: Signalyst DSC1
We have seen how Marcel output stage looks and works.
How, is the SE output of Andrea’s diy version configured, say if I want to use an electronically coupled Amp ( no trafos pls)
Andrea did not supply a schematic for his DSD dac output buffer board. However it had four outputs, one for each phase of each channel. Cursory visual examination looked kind of like a set of four diamond buffers along with some current sources. We elected not to use the buffer board since we liked the dac sound better direct into our line amp in SE mode. Maybe that's because our line amp has a certain sound that we like a like a lot, which was balanced against the sound we could get using Andrea's buffer. Some people might find his buffer sound more to their liking, don't know. I believe his next DSD dac will be offered with a new output buffer. Don't know if any new designs are available for sale yet or when that may happen. There is always development working going on and designs going through iterations. You would have to ask Andrea if you want to know more.
Actually the first flip-flops are still working in a single-ended manner because the digital input signal is single-ended. The digital signal becomes differential at the outputs of U21 and U23, and the actual DAC is differential.
As far as I'm concerned, the only thing that is flawed about it is the stuff Mark wrote. There is nothing wrong with using a differential structure to cancel out some imperfections.