I saw that too, Mani. To me it just shows how much Peter is ahead of the so called cutting edge with his new usb nos1 dac design.

Per

Some days ago I stumbled over this excellent interview in UltraAudio on Music Server design

http://www.ultraaudio.com/index.php?option=com_content&view=article&id=135:matan-arazi-on-music-servers&catid=31:general&Itemid=46

Here is an extract from the interview talking about noise:

Jeff Fritz: How important is noise -- electrical, mechanical, etc. -- in a music server? Is EMI or RFI an issue?

Matan Arazi: Extremely important. Once we’ve established that a music server is bit-accurate (and virtually all good ones are), and after we’ve reduced jitter to the minimum possible, we have to start looking at the analog aspects of the digital connection to the DAC. Let me explain this for a second: Even though the connection between the music server and the DAC is a digital one, that digital signal still passes through a cable, which is an analog medium. Transmitting a pure digital signal through any analog medium requires infinite bandwidth, which can be achieved only theoretically. Thus, the digital signals are modulated (the exact modulation type depends on the type of connection and cable) so they can be transmitted through a cable, and the modulation/demodulation process can add undesired effects to the signal. In most computer-based scenarios this isn’t a problem, but with a DAC it matters, because DACs bridge the digital and analog domains and are highly susceptible to analog noise. Furthermore, since the computer is an environment full of electromagnetic noise, some of this noise can be transmitted by the cable and work its way into the DAC. Based on our experiments, I believe that differences in the analog parameters of the connection between the music server and the DAC account for the majority of the differences in how different music servers sound, even when using the same DAC. It is this radiated noise (along with differences in grounding) which is also the reason why some people notice differences in the sound when different USB cables are used, or why music servers with solid-state disk drives generally sound better than those with mechanical hard drives. As before, less vibration and less noise mean better quality. (text in bold by me)

Further on XXHighEnd is mentioned favorable  

In addition, using dedicated playback applications, such as the excellent Amarra or XXHighEnd programs, is beneficial because these programs are carefully designed to optimize audio quality by minimizing various parameters inside the computer that can interfere with the playback or increase noise or jitter.

In my humble opinion this interview about Arazi's all out assault on a state of the art Audeeva Conbrio music server is a very interesting read for us computer audiophiles - with a lot of insight into what goes into different aspects of construction. Just thought I would share it.

Per

Peter Daniels website - http://www.audiosector.com/

PDF building instructions for his Chip Amp Kits

http://www.audiosector.com/nigc_kit-users_guide.pdf

Additional informations in this DiyAudio thread

http://www.diyaudio.com/forums/audio-sector/51381-audiosector-chip-amp-kits-dacs-chassis-4.html?postid=584319#post584319

Regarding bi-amping I remember Peter Daniel mentioning that the sound quality improves considerably using bi-amping - ultimately having one mono gainclone pr speakerdriver / side,

Best Regards,

Per

PS: Really enjoying to read about your experience into gainclone (and cable) territory. Keep it up.

I just want to send my deepest condolences to the Norwegians of this forum and to the Norwegian nation as a whole after the tragic events Friday. We feel the pain and mourn with you.

A big hug from

Per Borgen
Denmark

Thanks a lot Paul. And you are right about cases. I have found a few some time ago - but like with a lot of other stuff I can't find anything when I want to    So I am very grateful for the links. I'll give them a nice searchable description and sync them with my gmail account - hoping they won't disappear 

All the best,

Per

Thanks a lot, Paul for the pics. Nice job  Where did you buy the case and the trafos? Best, Per

Hi Paul, Thanks for sharing. I suppose you bought them from http://www.audiosector.com What about a nice picture showing your new amps?

I think you are absolutely right, Mani. Ground is very important. Some deliberately make ground wires thicker than signal / hot wires - both in a powercord and inside cabinets.

Regarding seperate scopes I have heard praise for the Tektronix scopes over at the Naktalk (Nakamichi tapedeck) forum. If I am right you won't need one in the multichannel / gigahertz range - a two channel megahertz scope will be enough for audio - even to monitor for instance a S/PDIF squarewave signal in the low megahertz range.

I bought a used 2-channel 20 mhz HP scope back in 2006 for 1000 DKK (around 120 pounds) but never got to (learn how to) use it due to a worsening in my muscle disease.

Wish you a good hunt for a cheap used scope or, maybe a handheld one or a PCI card that uses an older PC as screen and recorder.

Best Regards,

Per

PS: Please take VERY much care measuring the mains - at 110 / 230 volts ac it takes only mA to kill you if goes left arm - right leg...

Hi Mani and others, If you consider an AC regenerator / monitor, maybe this would pass the bill as it is an improved version of the older powerplants AND - from what I understand from Paul McGowans newsletters - a true scope built in... Don't know anything about the price, though...

http://www.psaudio.com/ps/products/detail/perfectwave-power-plant-5?cat=power

Per

Thanks a lot, Russ. I have bookmarked those for future use. Per

Wow. Thought you had opened a computerstore... Wishing you all the best. Per

Yes  Changed from Q1=4 to Q1=8 in 0.9z-4.1. Quit via "off". Started XXHE again ---- and sure enough - 8 is remembered... Same thing with 0.9y-8.

Lots of regards to your family too.

Per

No problem at all. I just keep Q1 at 14 as I cannot hear any difference through my low fi hifi Hoping for something better when health permits me to bring together some of the stuff I have in my archive.


No, it does not have anything to do with Q1 settings - I just do not have any "KS" prefix in XXHE (no matter which version) when I choose SPDIF out in my Vista 32 / Audiotrak HD2 / Via Envy24 setup. Analog out from the HD2 soundcard is the only one that can play Engine4 / Kernel Streaming. But I (still) cannot go any higher than 44.1 / 24 bit  Have tried to install the driver from Audiotrak (0.9xx something I think) but no way. (Will open a new thread on this when I have the strength to use time / energy on the issue)

But XXHE sounds great anyway - and I have to say that 0.9z-5 is running surprisingly well even with services shut down.

That's all for now. I will rest a bit...

All the best

Per

Hi Peter,

I suffer from the Q1 (set to 14) problem too - right now I am using 0.9z-5 Engine 3 (WASAPI) as my soundcard the SPDIF output / driver of my soundcard won't output anything using the Engine 4 (Kernel Streaming) setup. (I have not yet had the possiblity to change my signature to reflect that)

Sorry for not responding to this earlier.

All the best

Per

Russ, please do. Thank you very much.

Per