OS latency

[PeterSt]

Yes, GainClones ... (homebrew, though not completely by myself).

One of the major issues with high sensivety horns (115dB here) is noise, that is, if you don't use a pre and/or any other means of volume control (than digital). And the GainClones are completely silent (and 27dB of gain).

Although I have been researching the "Class D" leage only, hence not specifically any Class A means (I wanted to save some on my anual 12K KWh ) by now I can say that these little chips must be doing an even better job than I could know at buying them. I mean, back then (3 years ago ?) I wasn't hobbying with a DAC and the best sound ever, while in the mean time I do and all sounds as real as, well, real. So, real is real, and the GainClones are part of that (while it is the DAC which needs the improvement).

In the mean time though, I heard through another type of amp (also running cold, and also no Class D but *also* not a chip ), that there's potential for vast improvement. But the amp concerned has downsides as well, so it's only theory at this moment.

I'm not quite sure what the results will be with your Audio Note as a front-end, but try to bypass your TVC. Just for trials. You could be amazed. Be careful though for a "too sharp" sound, assuming the Audio Note is NOS.

Peter

[Nick]

Good to hear you are getting such excellent results with horns and gainclones, it gives me confidence in the potential of my system if I get a Phasure NOS DAC into it.

My Audio Note DAC is NOS and based on the AD1865 DAC. I’v done quite a lot of work on it, by far the biggest step was removing the mumetal potted analogue filter that comes after the I/V transformer and feeds directly into the input of the DAC output tubes. Audio note call it a "filterectomey", taking the filter out absolutely bought the DAC to life. So there’s no over sampling or filtering in digital domain (except what you provide in software) and no analogue output filtering other than the I/V conversion transformer’s bandwidth limitation. I don't have the equipment to measure the resulting DAC response but I do simile and tap my feet a lot when listening

The NOS and no analoge filter DAC approach works very well for me and is one of the main reasons I have been very interested in your work with the Phasure NOS DAC.
Nick.

[Marcin_gps]

Old topic, but I finally saw an occasional dpc reading of 1us today. My average dpc readings are around 2 to 2.5us after the system settles. I don't know if dpc directly tests the audio data flows of XX but I agree with comments about general sound quality improvements as the dpc's reported latency improves. Aggressiveness has reduced and naturalness of sound presentation has become markedly better, particularly as the last few micro seconds have come out of the dpc readings.

The system is a dedicated Audio build with everything cut that I can think of or have read about. Windows Explorer has also been killed which is how I normally play music.

Nick.

Nice result! Could you specify what modifications have you done to Vista? Your hardware isn't top notch, so I'm pretty surprised to see that your're getting 1us...

Best regards,
Marcin

[Nick]

Marcin hi,

I get the occasional 1us reading and 2-3us readings the rest of the time. The lowest sample latency the PC plays using the HiFace in Special Mode is 32 samples with Q1=1 which I think is 1 sample latency if I understand things correctly. The music plays fine but sounds better at Q1=3.

The PC has two BIOS configs and OS installations which I switch between to give a “thin” build for playing music and thick build with full H/W and OS features (eg multiple drives, networking, vista services running etc). The thin config is absolutely for music only with everything I can think of turned off, disabled or tuned to reduce background CPU load.

The thin build applies the tuning steps;

Bios, turn EVERYTHING off that is not needed essential for music and tune where possible for speed.

Disable Vista Services, I think I have ended up with 8 services that have to run.

No network - turn off N/W hardware and remove all drivers, no anti virus, windows defender, firewalls etc.

Systems settings, I’m running 2 cores (of 4), no disk sowp file, PCI lock on, turn off event logs and memory dumps on system errors - all the usual stuff.

Control Panel Applets, Disable absolutely EVERYTHING in every application not needed.

In device manager I disable EVERYTHING that I can (unused USB drivers, IDE drivers with no drive connected, PCI to PCI bridge drivers that are not used to play music etc etc)

Uninstall all unused software and start menu options, take everything out of the systems trays (clock etc etc)

Used Autoloads - turn off all drivers, auto start programs, software registrations etc that are not needed for windows (taking special care not to kill the PC boot altogether)

I overclocked from 2.6Ghz to 3Ghz (the PC will go faster but sound suffers) and run the fastest memory speed I can get from the front side bus.

Power setting configs discussed in the Windows OS tunning thread

I also kill Windows Explorer whilst playing music.

Its a bit impractical to write a build as there are literally 100s little things to turn off / disable or  config so it’s not practical. I just read as much as I could on forums and then rigorously disabled stuff if it’s not needed for music. There were a few rebuilds along the way when I overdid turning things off but mostly the windows boot option of “use last known good configuration” got me out of trouble.
I just wish it were possible to tweek the priorities of windows system processes as there is such a huge amount of raw processing power available if it can just be focused on the processes we need for music replay.

Regards

Nick.