Electronic Engineering and hi-fi set-up

[Blackmorec]

This morning I was looking out of the window as my wife commented on how hard it was raining. I looked but could not ‘see’ any rain and there were no puddles so I didn’t see any rings. Thinking about it I realised that I was looking out through very fine mesh mosquito netting, left over from summer, so I released the netting and let it roll up. Looking out of the window again I could now clearly see it raining.  While the mosquito netting is almost invisible and has very little if any affect on the lake view so wasn’t noticed, it completely obscured the fine detail of falling rain and its exactly these fine details that we use in hi-fi to provide sonic clues about soundstage, timbre, ambience etc.  So what’s the equivalent of the mosquito netting in hi-fi? Essentially it would be anything that obscures the system’s ability to resolve detail.  Remove them and hey-presto, it sounds like you’ve added something!  The electronics engineers who build our hi-fis are able to design, manufacture and measure equipment to perform at the very pinnacle of the art, but is that what we’re actually going to hear?  Not if there’s a step missing.....the set-up that ensures that there’s no sonic mosquito nets between you and your  music. 

 

[Kal Rubinson]

44 minutes ago, Blackmorec said:

So what’s the equivalent of the mosquito netting in hi-fi? Essentially it would be anything that obscures the system’s ability to resolve detail.

A low-pass filter?

[Speedskater]

Sometimes filters increase detail.

Like Polarized sunglasses.

At the classical music radio station, there was a complaint about hum on the host's microphone. It could not be heard on the station's good sound system or my hi-fi system. But the next morning it was vary audible on my clock radio.

[Blackmorec]

1 hour ago, Kal Rubinson said:

A low-pass filter?

Hi Kal, 

The mosquito net was an analogy for something you weren’t aware of that is robbing your hi-fi of detail. I would presume a low pass filter is a necessary part of the design 😁

[Kal Rubinson]

Just now, Blackmorec said:

The mosquito net was an analogy for something you weren’t aware of that is robbing your hi-fi of detail. I would presume a low pass filter is a necessary part of the design 😁

Just as the mosquito net is necessary for reasons other than transparency.  😉

[mevdinc]

Your analogy and description of the possible problem relates to electrical noise or similar in the system.
I clearly experienced a major difference between AC powered and Battery powered DAC. At the time  I had a  Zodiac Gold DAC.
Although I had also bought the special power supply designed for the DAC, whenever I used the battery power with the DAC the SQ was much better. Especially with the lower registers, the bass sounded much cleaner, better defined and more pleasing to listen to. I always had to turn the volume up as I could play much louder, presumably because of the lower distortion/noise level.
 

[Blackmorec]

42 minutes ago, Kal Rubinson said:

Just as the mosquito net is necessary for reasons other than transparency.  😉

‘Left over from Summer’.....the inference being that it was no longer needed but forgotten because it was more or less invisible. Just an analogy Kal, not the point of the discussion, which was, is there something in your hi-fi that your not aware of that could be robbing it of detail?

 

 

[Blackmorec]

25 minutes ago, mevdinc said:

Your analogy and description of the possible problem relates to electrical noise or similar in the system.
I clearly experienced a major difference between AC powered and Battery powered DAC. At the time  I had a  Zodiac Gold DAC.
Although I had also bought the special power supply designed for the DAC, whenever I used the battery power with the DAC the SQ was much better. Especially with the lower registers, the bass sounded much cleaner, better defined and more pleasing to listen to. I always had to turn the volume up as I could play much louder, presumably because of the lower distortion/noise level.
 

Yes exactly! And the important point is that the battery power didn’t add bass......rather the noise from the AC was robbing the system of bass.  My point was to illustrate that a lot of improvements don’t actually add anything......they just stop subtracting something. A better cable doesn’t necessarily add soundstage or midrange clarity, it just stops impairing those details as much. 

[Kal Rubinson]

13 minutes ago, Blackmorec said:

‘Left over from Summer’.....the inference being that it was no longer needed but forgotten because it was more or less invisible. Just an analogy Kal, not the point of the discussion, which was, is there something in your hi-fi that your not aware of that could be robbing it of detail?

Possibly but I am always experimenting to ferret out those matters.

 

8 minutes ago, Blackmorec said:

And the important point is that the battery power didn’t add bass......rather the noise from the AC was robbing the system of bass.  

No, the other PS was adding noise.  The bass was always there but the added noise made it difficult for the listener to perceive it.    

[mevdinc]

35 minutes ago, Kal Rubinson said:

Possibly but I am always experimenting to ferret out those matters.

 

No, the other PS was adding noise.  The bass was always there but the added noise made it difficult for the listener to perceive it.    

Was the PS adding noise or falling to reduce it as well as the battery?

[Ralf11]

3 hours ago, Blackmorec said:

 is there something in your hi-fi that your not aware of that could be robbing it of detail?

 

 

a USB cable that meets spec.?

[marce]

2 hours ago, mevdinc said:

Was the PS adding noise or falling to reduce it as well as the battery?

How would the battery reduce the noise? Kal was correct.

 

Of course without electronic engineering and the advances made over the years we wouldn't have the kit we do today.

There is also a whole wealth of information on low noise design in electronics, signal integrity and EMC, many more sensitive designs out there than audio. Looking at simultaneous witching noise is interesting in relation to noise from digital circuits. Layout is critical for low noise electronics, get that wrong and all bets are off, but there is as said many sources of information and results from testing etc. Then there is filtering... especially of DC...

Finally, having separate power supply's with umbilical's, many add on boxes with extra cabling (clocks!!!!) is not the best way for a noise free system, loops everywhere, without some serious measurements, you are only guessing whether its reducing noise or adding noise and remember noise can also enhance the audio, making it more enjoyable to some, 2nd harmonic and some tube amps is one example.

Power delivery systems have been discussed often, with digital its not just the front end supply that is critical, far more critical is the on board supply components such as decoupling capacitors, local supplies next to the device they are powering. Interesting with battery's without front end regulation the internal impedance rises with frequency, that leads to increased noise and possibilities of power fluctuations during heavy digital switching. 

[Ralf11]

8 minutes ago, marce said:

witching noise

 

 

you have put your finger on the problem for most audiophool gear

[Blackmorec]

1 hour ago, marce said:

How would the battery reduce the noise? Kal was correct.

By replacing the source of the noise.   The AC mains power and associated cabling

 

[Ralf11]

this is a quantitative issue: does the battery have more noise than an AC outlet power supply?  which is easier to filter out, etc.?

 

here is an oldie but moldy for those wanting to find out...

https://tf.nist.gov/general/pdf/1133.pdf

[Arpiben]

35 minutes ago, Ralf11 said:

this is a quantitative issue: does the battery have more noise than an AC outlet power supply?  which is easier to filter out, etc.?

 

here is an oldie but moldy for those wanting to find out...

https://tf.nist.gov/general/pdf/1133.pdf

 

Completing your reference some measurements. Not all batteries are equal vs noise...

http://www.hoffmann-hochfrequenz.de/downloads/NoiseMeasurementsOnChemicalBatteries.pdf

[sandyk]

7 hours ago, Speedskater said:

Sometimes filters increase detail.

Like Polarized sunglasses.

At the classical music radio station, there was a complaint about hum on the host's microphone. It could not be heard on the station's good sound system or my hi-fi system. But the next morning it was vary audible on my clock radio.

 

I believe you, but as a technical person can you offer a plausible explanation for this ?

 Are you talking about FM stereo ?

[sandyk]

24 minutes ago, Arpiben said:

 

Completing your reference some measurements. Not all batteries are equal vs noise...

http://www.hoffmann-hochfrequenz.de/downloads/NoiseMeasurementsOnChemicalBatteries.pdf

 All batteries have some noise, with perhaps some such as LiFePO 4 types being lower noise than most. However, batteries normally  need to be connected using metal to metal contacts, unless they are soldered in. This also introduces additional series resistance, as does the wire needed to connect them to the device to be powered. They should also be bypassed at the device end by suitable value capacitors to reduce any HF noise, as well as RF/EMI picked up on the often relatively long connecting leads .

[Albrecht]

3 hours ago, marce said:

How would the battery reduce the noise? Kal was correct.

 

Of course without electronic engineering and the advances made over the years we wouldn't have the kit we do today.

There is also a whole wealth of information on low noise design in electronics, signal integrity and EMC, many more sensitive designs out there than audio. Looking at simultaneous witching noise is interesting in relation to noise from digital circuits. Layout is critical for low noise electronics, get that wrong and all bets are off, but there is as said many sources of information and results from testing etc. Then there is filtering... especially of DC...

Finally, having separate power supply's with umbilical's, many add on boxes with extra cabling (clocks!!!!) is not the best way for a noise free system, loops everywhere, without some serious measurements, you are only guessing whether its reducing noise or adding noise and remember noise can also enhance the audio, making it more enjoyable to some, 2nd harmonic and some tube amps is one example.

Power delivery systems have been discussed often, with digital its not just the front end supply that is critical, far more critical is the on board supply components such as decoupling capacitors, local supplies next to the device they are powering. Interesting with battery's without front end regulation the internal impedance rises with frequency, that leads to increased noise and possibilities of power fluctuations during heavy digital switching. 

""Of course without electronic engineering and the advances made over the years we wouldn't have the kit we do today."

True that. And it is high performance audio electrical engineering that have really advanced, - guess what, - high performance equipment.

Where-as electrical engineering outside high performance audio, in different disciplines, - have actually hindered development. This is especially the case in multi-function computer design, - where certain engineers confuse design elements that make performance of many functions very good, and one function, (audio), - perform less well.

One example of this is Esoteric's VRDS NEO transport. Where-in many designers thought previously that software/firmware error correction didn't really do as good a job as super-accurate, beefy motor & magnesium disc clamping mechanism.

""Finally, having separate power supply's with umbilical's, many add on boxes with extra cabling (clocks!!!!) is not the best way for a noise free system, loops everywhere, without some serious measurements, you are only guessing whether its reducing noise""

Not really. High performance audio engineers measure and listen for that noise. The potential device purchaser doesn't need and shouldn't have to measure, - the proof will be in the comparative listening, - this will determine to them the effectiveness.

 

"far more critical is the on board supply components such as decoupling capacitors,"

No, far more critical is the HF noise leakage, and the out of phase AC current, sent back into the mains supply that also affect other sensitive digital gear in the chain. John Swenson has written about this, somewhat extensively, and provides great explanations about what is actually occurring with these low voltage digital circuits.

 

[fas42]

Good topic for a thread, Blackmorec ... the "equivalent of the mosquito netting in hi-fi" is the low level haze, noise, distortion that essentially every setup 'adds' to the signal as it passes through - it requires hearing that very same rig stripped of these audible degradations - rolling up the net - to understand what has been happening.

 

Why I cottoned on so strongly, early in the piece, as to what was needed was that I 'accidentally' triggered the catch holding the net down; it instantly popped up - and I got a shock at the view. Trouble was, the spring holding the net up was extremely weak, and the net slowly rolled down again ... . But, I could tighten up the spring, for a temporary 'fix', and hey presto! The net went up again ... I really got fed up playing the game after many, many months of this 😜.

 

What lets the net down? ..just about everything, 😉. Why does one team win over and over again in Formula 1, in a particular season; and the "other one" always fails? And the situation is reversed in the next season? Is it - the engine, the chassis, the electronics, the team spirit, the driver, ... the colour of the device holding the wheels on? 😄 ... ummm, some people call it, "the weakest link" ...

[Shadders]

10 hours ago, Blackmorec said:

 So what’s the equivalent of the mosquito netting in hi-fi?

Ear wax.

[fas42]

The battery vs. mains saga continues ... there is no, The Solution!! It's always an engineering process - a poor battery attempt will be no better than a poor AC section; either mechanism will be do the job well enough, provided enough thought, and testing, has gone into it ...

[Kal Rubinson]

8 hours ago, mevdinc said:

Was the PS adding noise or falling to reduce it as well as the battery?

That doesn't make any sense to me.  If the source of the noise is inside the device, neither should affect it.  If it exists with the PS, it or the AC line is the culprit.  The battery (assuming it is adequate to the load) should not introduce any.

 

[Kal Rubinson]

5 hours ago, marce said:

How would the battery reduce the noise? Kal was correct.

 

4 hours ago, Blackmorec said:

By replacing the source of the noise.   The AC mains power and associated cabling

Removing the AC/PS reduces/removes the noise.  The battery neither adds nor removes anything (ideally).

[fas42]

Just continuing on the battery vs. mains issue, it's been interesting to see how the local audio friend has developed in his thinking - early in the piece, especially in respect to vinyl, he decided that AC had to go! He's done a huge amount of experimenting over the years, with a large variety of battery solutions - only to, just now, come full circle !! 😲 Before the last visit, he mentioned that as an idle experiment he fired up the mains supplies, for the first time in ages - and it sounded better! To him, at that moment!

 

So, what's going on? Is it because "it's different", or, has the battery solution slowly sagged, deteriorated in some area, unnoticed by him? He suspects the latter, and I would tend to agree with him - he aims to go through everything, check and 'refresh' the whole battery configuration; thereby evening up the playing field, and then do more thorough comparisons ... unfortunately, it wasn't a good time, in the last visit, to do some A/B ing.

 

Which emphasises a theme that's critical, IME. Just because you think you've done everything to make the system work right, in fact is a 0% guarantee that such is the case - the net can fall down from the 'slightest vibration' - and so you have to be constantly vigilant, and know how to check the SQ.