High End Audiophile thread

Might be cool to try out some of the other things they suggest. Some I bet is just paranoia or snake oil ideas.

I have most of those things going on that you mentioned anyway.

 

I edited to say that its also recommended to use a quality USB to optical on the external USB drives as well !!

 

Yeah, I know the device you are talking about. USB to Optical...pricey gear.
Or rather optical/USB interface, using optical to isoltae the USB connections.
Have look here->link

 

Yeah thats one they seem to like.
Sooo much to read !

Whats mad is that when you want to purchase, you have to contact them for a quote.

 

Something that has cropped up a lot is how a stable power supply on everything, even the OS drive makes a difference.
Battery packs have been tested on those builds that will accept them and are highly praised.

I wonder if there is a cheaper method that might give most of the improvements.
ie using capacitors as battery / a capacitor hybrid circuit, on the power supply rails.

There are multiple issues with this, not least related to slower rise in voltage levels on power up, large instantaneous loading of the PSU on power up, potential ringing on the power lines...
Some of these arent too hard to get round.

 

I've reached my reading plateau for the day and indeed ran out of day hours ago!
My observations so far follow.
Much of it is common sense from an electronic engineers perspective, its how much it matters for digital audio that is of concern.


The most basic principles are to avoid electrical and EM noise getting into the main PC, being generated by the PC (as much as possible), avoid all of that getting into the DAC and prevent the DAC unit from generating noise (if possible) or receiving any from its power supply.
It appears that digital audio is very sensitive to noise from a PCs operation.
Or to be more precise, our hearing is so extremely sensitive, it can tell the difference from even the tiniest changes in how a PC or connected equipment operates if the hifi equipment is revealing enough.


Electrical noise is generated/transmitted in a number of ways:

1) through EM radiation. All current flow has a magnetic component. a Static flow (constant flow rate) does not induce current flow in nearby wires, a changing flow rate (AC) does.
PCs are rife with changing flow rates from signals, clocks and data.

2) conducting through power rails. All components connected to the same power supply will transmit their noise between each other through the power rails.
The power rails will also pick up some EM noise as well which will be sent to all connected devices to some degree.

3) generated by power supplies. The power supply itself will generate noise, this is especially so for switch mode PSUs such as a PC uses.
Anything connected to the PSU will receive this noise.
It will also be transmitted around the PC by EM radiation.
Using separate Battery packs for every component is the ideal power source for quite a few reasons.
As close to achieving this as possible while being practical is what should be looked for.

4) through signal paths. This may sound contentious, but signal paths are still analogue conductors and noise is carried on them.
SPDIF coax lines or USB can pick up noise along their length (even on the shield) and can transmit noise through the signal path that is modulated onto the signal.
Some designs dont reject noise from the power rails and shield.

Although SPDIF optical and other optical signal paths do not pick up noise along their length, they can still transmit noise between connected circuits by modulating the power to the light producing diode.
Clearly this will be less noise than a wired connection, but for audio it should be considered.

Noise on signal paths does not affect the data being sent, it affects circuits and the noise effects can add up, be amplified, or carried further into other circuits.
The net result that matters is whether it affects the timing of the clock pulse that clocks the data being sent "into" the DAC chip.

5) The PC itself is a HUGE generator of electrical and EM noise, so ways of reducing this will help a lot.
(But it also appears that a faster response of the PC may help too, tighter memory timings point to this - for increasing sound quality, not helping EM).
Reducing the processing the PC is doing or changing the way the processing is done has an effect.
Reducing the amount of power used by the PC has a 2 fold effect.
a) it draws less power from the PSU. Because the power draw isnt constant, it makes the PSU and power rails noisy, so less power draw means the noise amplitude decreases on the power rails. The power rails also radiate a little EMI.
b) EM radiation level is proportional to the voltage level in an AC circuit, so less power used by the PC reduces the amplitude of the EM radiation from PC components.
This means other conductors will pick up less EMI.
Some parts of the PC will run with less voltage and still give suitable performance.

6) The wall power supply and power leads to your PC/DAC/USB drive etc. Other devices in the house transmit noise on the mains and power leads pick up EM noise in the room.
You can shield power leads and filter some noise.


This all matters because:
Data must be clocked into the DAC at precise intervals.
Tiny changes to the timing of each pulse can be picked up by human hearing.
Each clock pulse has a start time, a rise time (how long it takes to raise its voltage) and a trigger voltage (when it has reached the voltage level to signal that the data can be clocked through).
Any noise on the clock signal can affect the start time and how long it takes to reach the trigger voltage.
But also crucially, the trigger voltage can vary from noise within the DAC.
It is crucial to eliminate as much noise as possible.


In my last post, I proposed using capacitors to stabilise the PSU.
Different value capacitors can be used in parallel to cope with different frequencies of noise and their harmonics, going to a device and coming from it.
By placing the capacitors close to each device, they will be able to perform a certain amount of isolation, even when connected to the same power supply.
This wont be as good as a separate battery to each device, but it might be good enough to avoid the large inconvenience and expense of using many sets of DC batteries.

Thats all for now, this is going to get interesting
Let me know if this is helpful, please point out any errors.
I keep thinking of more to add or how to make something clearer but I have to click submit at some point
Good night (at 7:43am!)

 

Great read Muff :thumbup:

I've been listening mostly to my player recently. Been making DVD audio Discs Would you be able to research DVD audio if you get the chance, MLP to be precise

Thanks dude,
RagDoll.

 

Bear in mind that I cant discuss making of disks from certain downloads!
What do you want researched about MLP?

For example, if you asked me to research bitrate, I wouldnt know what you want to know

 

Yeah, I know, I mean the electronics of it and the main thing I want to know is the difference between DVD audio and SACD's?

thanks,
RagDoll.

 

@Muff, for the PSU, there is many caps on all the lines, there are also many caps in the connected devices. This is where the debates starts to come into play.
Example, people say the inside of a PC is noisy, power PSU is noisy, it could be sure depending on a few things. If we hook up say, a ASUS STX and measure it, the card provides better noise measurements then many external devices. So where is the noise?
Some have been saying SATA filters are a good idea but I am not sure how much stock I put into them.

I guess making a more precise system could only be good for audio.

 

I mentioned 2 advantages

1) you can use different value caps and types of caps (in parallel) that will respond better to the frequencies and harmonics that are common on the cable, either generated by the PSU, by the connected devices or from EMI.
2) by placing the caps closer to each device, they will provide better isolation of each device from each other. This removes power line noise at source generated by connected devices (or a fair amount of it).

Another is it puts a better buffer between the PSU and each device so the PSUs noise isnt as strong.

This is above what manufacturers have included in their products.
It may be unecessary to do it for every device, it may make little difference to group some devices onto the same power point, as long as their is enough isolation where it matters.


SATA filters are more acclaimed than the USB to DAC filter from what I've read so far!

 

My background is in electronics and engineering. I understand the intricacies of filtering components. I think I am going to start adding filter caps to my opamps I build for myself also. The thing we have to keep in mind is much of this stuff would only start to be of affect when other aspects have been taken care of.

Maybe I should use my contacts to try and build a high end 100% audiophile music system?
I already have quite a few parts. What do you think as it might make a great article?

I wonder how high end it should be though, I want people to read it and get ideas not look at it as something they can never do or own.
Have to be very careful with the price to performance here.

 

If you're gonna do that, which I think is awesome, please use the Auzen HD Hometheatre card and get some Bic America speakers to go with it Or, if you're gonna go really high end, some Polks, or DT's

regards,
RagDoll.

 

Funny you mention it as that is the card I was planning on using. However, I was also planning on putting a DAC with it also.
I think, I want to try and keep things as generic as possible. More as a how to, to tune your system...maybe I don't know. Just some ideas right now.

 

Yeah that has become quite obvious
I think you will have a fair amount more experience than I have, after studying my contracts have been varied between electronics and computing with more going to computing.

Agreed, was going to say the same, but then got distracted by thoughts of how much they claim isolating SATA devices helped.

I'd love it, super idea.

I have a spare PC that fits the bill quite well (quad core, Intel, no iGPU, large motherboard with components spread out - all positive criteria I have read).
It has an old PSU that I wouldnt choose for this project though.
But even cheap upgrades will have to wait until February or March probably as I'm skint.
Theres an old uncalibrated scope poking out of a cupboard that might be useful still, needs some leads.

 

I already have been working on such a device
Totally quiet, no moving parts to start with.
Now, just think of some optimizations to throw in the mix.
I am hoping I can add Jplay to the software system.

 

I studied computers, but there was a few parts of the course that focused on electronics. However, I'm more of a teach myself type and most of what I know is self taught, even learning alot here on G3D I did this project a while ago, built my custom machine. I worked at 2 companies specializing in building and repairing PC's, so building my PC wasn't that difficult, just the CPU fan was a bit of a challenge. It's a high end HSF, and as you probably know, the 3rd party ones that aren't intel are all different... lol I made sure I got a PSU that was both powerful and quiet, which it is. Also, made sure the mobo was grounded. This is a big thing if you want the cpu and other components to work well, without shorting You probably know all this, but Rob, if I can be of assistance or anything, just pm me and I will help

best of luck with it,
RagDoll.

 

Well as many of you may know if you have any interest in electronics is on paper, it is very precise however, in the real world electronics is very imprecise and tolerance ridden.
It is all about what component does the job with some very laxed tolerances sometimes.
This may be where people are hearing improvements by helping to isolate and improve on the tolerances of some components. That I can understand but some things would also just be paranoia or snakeoil.

 

agree 100%

 

How about you add a few minor DIY mods into it?
Low cost, high effect, improving the efficiency of existing components would be very popular, since everybody would be able to use it.

A bit like SilentPCReview did with silencing a PC.