Keith_W system

[Keith_W]

20 hours ago, jamesg11 said:

Jussi's HQPlayer forum thread seems to have a consensus that if you want to max upsampling in a dac that can go say 512 dsd in 2 channel, then you need the specs outlined by Keith above. 

 

Slight correction there, James. Jussi's intention is the same as mine - he wants to convolve 8 channels at high DSD sample rates. If you only need 2 channels at DSD256-512, the hardware requirements are much less. 

 

1 hour ago, ghost4man said:

 

Guys what would you recommend in this regard in terms of a DAC which also has USB capability to go out from the computer/laptop.

 

I'm wondering if the progression down in terms of CPU requirements is geometric or arithmetic. For example, if at max upsampling - 512 DSD

requires (X) amount of power would 256 DSD require half that. Apologies for the oversimplification but just trying to get a gauge of what

one would be looking at CPU power wise.

 

Hi Oz. To answer your first question, "which DAC to recommend", it all depends on how many channels you want to output. If you need anything more than two channels, then you have two options: 

 

1. Buy a multichannel DAC in the first place, or

2. Gang together as many 2 channel DAC's as you need. 

 

For option (2), i.e. ganging together DAC's, there are three very important limitations.

 

First, the DAC's must be clock synchronized. This means the DAC's need a clock input, and you need to purchase an external clock.

 

The second important limitation is that you need a single ASIO driver to run all your DAC's. There is no software that I am aware of that can output (for example) the first two channels to ASIO device 1, the next two channels to ASIO device 2, and so on. 

 

To get around the ASIO driver limitation, you will need to invest in a sound card like the RME HDSPe AES-32. You set HQPlayer to output to RME's ASIO device. Then you use the RME ASIO device setup to route input channel 1 to output channel 1, input 2 to output 2, etc. 

 

I bought one of these cards ($1500!!!) and it is gathering dust because I eventually opted not to go this route. But I am keeping it for the time being because I might consider buying four DAC's. 

 

The third limitation is that your DAC's need to have sufficient output voltage, and sufficiently low output impedance to drive your power amps directly, since you no longer have a preamp. This can be more difficult than you think, PARTICULARLY if you are doing it like me and have four vastly different driver types, all with different sensitivity, being driven by four pairs of dissimilar power amps, each with different gain structure and input sensitivity. I can tell you that this has given me major headaches, and I am in the process of solving it. 

[Keith_W]

@CryptiK thanks for posting your PC pictures. I have been posting some questions on a computer forum to get some help with watercooling. The consensus seems to be that my proposed setup (280 x 140 radiator) should be sufficient to cool the 6950X and GTX 1080 Ti. They also suggested to gang the fans to the CPU fan header so that it can ramp up/down the fans as required. 

 

In my shopping travels, I came across something called a radiator mount, which I was not aware was even a thing. It looks as if this would allow me to mount my radiator externally. Hmm, I might be able to drill some holes into my SGR equipment rack and fashion some kind of clip-on arrangement that would let me mount a huge arse radiator Hmmm, options, options ...

[Martykt]

22 minutes ago, Keith_W said:

 Hmmm, options, options ...

 

Is there still going to room for the Acapella's once the Broadwell-E is finished ?? 

 

[ghost4man]

23 minutes ago, Keith_W said:

 

Slight correction there, James. Jussi's intention is the same as mine - he wants to convolve 8 channels at high DSD sample rates. If you only need 2 channels at DSD256-512, the hardware requirements are much less. 

 

 

Hi Oz. To answer your first question, "which DAC to recommend", it all depends on how many channels you want to output. If you need anything more than two channels, then you have two options: 

 

1. Buy a multichannel DAC in the first place, or

2. Gang together as many 2 channel DAC's as you need. 

 

For option (2), i.e. ganging together DAC's, there are three very important limitations.

 

First, the DAC's must be clock synchronized. This means the DAC's need a clock input, and you need to purchase an external clock.

 

The second important limitation is that you need a single ASIO driver to run all your DAC's. There is no software that I am aware of that can output (for example) the first two channels to ASIO device 1, the next two channels to ASIO device 2, and so on. 

 

To get around the ASIO driver limitation, you will need to invest in a sound card like the RME HDSPe AES-32. You set HQPlayer to output to RME's ASIO device. Then you use the RME ASIO device setup to route input channel 1 to output channel 1, input 2 to output 2, etc. 

 

I bought one of these cards ($1500!!!) and it is gathering dust because I eventually opted not to go this route. But I am keeping it for the time being because I might consider buying four DAC's. 

 

The third limitation is that your DAC's need to have sufficient output voltage, and sufficiently low output impedance to drive your power amps directly, since you no longer have a preamp. This can be more difficult than you think, PARTICULARLY if you are doing it like me and have four vastly different driver types, all with different sensitivity, being driven by four pairs of dissimilar power amps, each with different gain structure and input sensitivity. I can tell you that this has given me major headaches, and I am in the process of solving it. 

 

Keith,

Got you mate loud and clear.

As you know I have a 3 way mains speaker setup.

 

Actually I need to change that and state that it is 4 way because the subs - linked in series - are part of the minidsp XO configuration.

 

Thus far going active has been a mine field.

I am in the process of resolving my mains power issue because the existing circuit cant deal with what is already there.

I happened to find this out when a friend of mine @gonefishing999 came to my place with the view to inserting his 5 channel Lexicon

power amp. 

It would not work.

Fortuitously my neighbour across the road is a sparky who will do the essential work to make sure it is above board.

In terms of running cables through the ceiling etc, I will be doing that.

I am going to use 4mm*2 csa cable to give me a 25/32amp dedicated circuit. I say both figures as I am not sure what the maximum load is

today. I was told by a colleague that it may have dropped from 32 amp to 25 for this thickness. 

I'll find out soon enough.

Now 25 amp may seem enough for a dedicated circuit BUT it should be remembered that I am running maggies and I am building a Holton Amp

which will give 800wpc just for one driver.

A quick addition over 3 pairs of drivers using the same sort of amp - depending on how the Holton performs - gives a theoretical maximum

of 4800 watts. That equates to 20 amps at peak draw.

I think I should be safe.

 

This is why I am trying to figure all this out now so I dont get caught with my pants down later on.

 

Its amazing and intriguing the manner in which the conversation has steered towards the importance of the source, namely the limitations of the PC

when used in conjunction with software like HQP outputting to the right DAC.

 

Ozzie

[Keith_W]

Well Marty there are still some things that I don't know e.g. I don't know how much cooling I need, and then (the most important question of all) ... how much noise the cooling system will make. When faced with problems like these, my usual instinct is to over-engineer. I know that big radiators with slower fans are quieter, so i'm going to go for the biggest radiator and slowest fan I can find that will fit in my case. 

[Satanica]

40 minutes ago, Keith_W said:

 

2. Gang together as many 2 channel DAC's as you need. 

 

For option (2), i.e. ganging together DAC's, there are three very important limitations.

 

First, the DAC's must be clock synchronized. This means the DAC's need a clock input, and you need to purchase an external clock.

 

The second important limitation is that you need a single ASIO driver to run all your DAC's. There is no software that I am aware of that can output (for example) the first two channels to ASIO device 1, the next two channels to ASIO device 2, and so on. 

 

I think you can do this with JRiver utilising linked zones, but for playing back audio files only, not video files. 

Edited March 24, 2017 by Satanica

[Keith_W]

Oz, you might like to read some entries I wrote in my blog: link 1 and link 2. The second link discusses various multi-channel DAC's. Which DAC you choose depends on how spendy you want to get. 

[Red MacKay]

28 minutes ago, ghost4man said:

@gonefishing999

I am going to use 4mm*2 csa cable to give me a 25/32amp dedicated circuit. I say both figures as I am not sure what the maximum load is

today. I was told by a colleague that it may have dropped from 32 amp to 25 for this thickness. 


 

 

If you are putting in a dedicated line, just go straight for 6mmsq.  The extra cost of wire is miniscule compared to the effort and labour involved.

 

Just make sure first that the powerboard to your home will not draw more current than what the line to your house from the street can carry. Sometimes it won't.  Legally you cannot exceed this, even though you are not drawing anymore current than you presently are.

 

I don't mean to be the police here, just pointing this out as most sparkies won't let you do it.

[Martykt]

1 hour ago, Keith_W said:

Well Marty there are still some things that I don't know e.g. I don't know how much cooling I need, and then (the most important question of all) ... how much noise the cooling system will make. When faced with problems like these, my usual instinct is to over-engineer. I know that big radiators with slower fans are quieter, so i'm going to go for the biggest radiator and slowest fan I can find that will fit in my case. 

 

That's one thing that I highly respect about you and your system Keith, you aren't afraid to keep pushing and learning to create something special.

 

I never was one for 'good enough' either.

Over-engineering is usually worthwhile in my experience.   

[CryptiK]

5 hours ago, Keith_W said:

@CryptiK thanks for posting your PC pictures. I have been posting some questions on a computer forum to get some help with watercooling. The consensus seems to be that my proposed setup (280 x 140 radiator) should be sufficient to cool the 6950X and GTX 1080 Ti. They also suggested to gang the fans to the CPU fan header so that it can ramp up/down the fans as required. 

 

In my shopping travels, I came across something called a radiator mount, which I was not aware was even a thing. It looks as if this would allow me to mount my radiator externally. Hmm, I might be able to drill some holes into my SGR equipment rack and fashion some kind of clip-on arrangement that would let me mount a huge arse radiator Hmmm, options, options ...

 

No problem. As you can see I run a full size tower with a rad in the top and one at the bottom. 

 

You can use a rad mount and run it externally sure. You can also use something like a MO-RA3 and use a couple meters of tubing/quick disconnects and place the rad elsewhere, where the noise of the fans would be barely if at all audible in your sitting position.  

[Keith_W]

Holy cow, I just googled what a MO-RA3 is. It's a monster! 

 

I think for now i'll just build a 280 x 140 rad into the case and see if that's cool and quiet enough. If it isn't, then i'll consider a MO-RA3. Something that large will probably require a really "special" pump as well, and the more "special" the pump, the more noise it will make. 

[Keith_W]

I asked Jussi what machine is better for HQP - more cores, or faster pipeline. He replied here. 

[ghost4man]

@Keith_W

Hi mate I found this on the Whats Best forum:

http://tweakaudio.com/EVS-2/Computer.html

Worth a read I think. Goes into great detail what he did for his set up to get HQ Player to work optimally.

Let me know what you think.

 

Hope it helps.

 

Ozzie

[Keith_W]

What a difference 18 months makes! These pictures were taken in October 2015, when my system was very much in flux. I was in the process of selling off equipment to swap over to my current setup. That massive black sub on the right in the first picture is a pro audio Genelec sub, which I borrowed from a friend who was kind enough to lend it to me. Behind the sub was a rats nest of equipment and cabling: 

 

 

 

And here are some pictures I took today. My new Vitus RI-100 amp has arrived, and it replaces the SGR (which is now listed for sale on SNA). The cabling has been tidied up. 

 

 

 

The wooden boxes on either side of the Vitus are the subwoofer plate amps. I am thinking of buying some aluminum plate and screwing it on the front of the boxes to make it match the system aesthetically. Opinions? 

(And yeah, I know it won't improve the sound one bit ... but aluminum is not expensive!)

 

 

To be done: take a new set of measurements. There are still a few refinements I need to make to the system, e.g. a new LPSU for the PC, upgrade the cabling, and probably upgrade the PC. 

 

 

[Cardiiiii]

Looks stunning! Congrats!

[Primare Knob]

You are very much the front runner of my w** dreams.

There are Mytek DAC's that have clock in and output and a 6 channel (USB) driver.

There is also Exasound which you probably are already familiar with.

 

The RME card is probably the best pathway when hooking up multiple 2 channel DAC's. But you have to pay attention to what is happening inside the DAC. Some DAC's reclock the signal which likely will cause timing drift between multiple units. Pro audio has more options but not always helpful.

EDIT: Just been reading up on your blog. Does clock drift still occur when multi DAC's are fed the same clocking signal via AES/EBU from the RME card?

 

Ever did some read up on Audinate Dante. It is pro audio but would be very useful in creating a multi channel setup using multi equipment. It is ethernet based and does sync timing of muliple channels and equipment in real time.

Edited October 16, 2017 by Primare Knob

[Keith_W]

1 hour ago, Primare Knob said:

The RME card is probably the best pathway when hooking up multiple 2 channel DAC's. But you have to pay attention to what is happening inside the DAC. Some DAC's reclock the signal which likely will cause timing drift between multiple units. Pro audio has more options but not always helpful.

EDIT: Just been reading up on your blog. Does clock drift still occur when multi DAC's are fed the same clocking signal via AES/EBU from the RME card?

 

I don't know if multiple 2 channel DAC's would suffer clock drift if fed the same signal from the RME card. I have not tried it. The reason I haven't is because the RME doesn't do DSD. It has been my intention for some time to see if the RME supports DoP. It may do, but that would be another learning curve which would be largely academic for me at this point in time. 

 

If I decided to spend a bootload of money and buy multiple quality 2ch DAC's (e.g. Playback Designs are very nice!) then I might do some experiments. But the problem with most 2ch DAC's is that their output voltages are lowish which means that most of them have difficulty driving power amps directly. 

[Primare Knob]

Is it the output voltage that doesn't allow for direct drive into a power amp, or is it the power supply chain of the DAC that doesn't.

There is a "standard" for output voltage in audio equipment. Some other knowledgeable guy told me that most DAC's will over drive a power amp with to high an output voltage.

I have seen for myself that it differs per DAC and some can while others can't. But I don't have a clear graps yet on why that is. My only jumped conclusion sofar is that a beefier power supply seems to do the job better.

[Keith_W]

Well, here is one thing I do not understand: supposedly, most power amps require 2.0V to drive the amplifier to full volume. 

 

My experience is somewhat different. My NADAC is able to output up to 6V, yet it still isn't able drive some of my power amps to full volume (most notably, a number of borrowed solid state power amps I tried), despite the published specs of the said power amps saying that 2.0V = full volume or similar. With most of these power amps, I can gain more volume by using a matching preamp. 

 

This is one of the reasons I am using an integrated solid state power amp (the Vitus) to drive the bass units. Firstly to get more volume, but more importantly so that I can trim the volume before running sweeps through Acourate. Although it is possible for Acourate to correct for volume mismatch between different drivers, it is better that those drivers are as closely matched as possible before starting. 

[Primare Knob]

https://www.minidsp.com/products/usb-audio-interface/u-dac8

 

Came across this one today. Cheap enough to fool around with. It does have a rather hi-ish output impedance. So I'll doubt it will do good driving a power amp directly.

Edited October 17, 2017 by Primare Knob

[roh008]

On 3/24/2017 at 12:46 AM, Keith_W said:

HOWEVER! From my own experience with HQPlayer, the biggest jump in CPU requirements is going from PCM to DSD. In my current setup, PCM 384 at 8 channels uses "only" 20% CPU power. OTOH, DSD at 256MHz uses 95% CPU, and this is on an i7-6700 on a B170 motherboard with 16GB of RAM. 

Great showcase thread Keith,

 

I was about to ask why need for the raw processing power, but this answered it for me.

So next question, if all of my music collection is not DSD native, but the DAC supports DSD, is their audible benefit to up-sample and convert it?

Also some great insight from @CryptiK on what fan options, I scratched the surface when looking at changing the fan on my water-cooling pump, and started to come across what you wrote about. I might have to inbox box you if you don't mind, as I'm looking to replace my kuhler radiator fan to a quieter one.

 

 

Thanks

 

Roh

[davewantsmoore]

On 10/16/2017 at 11:41 PM, Keith_W said:

My experience is somewhat different. My NADAC is able to output up to 6V, yet it still isn't able drive some of my power amps to full volume (most notably, a number of borrowed solid state power amps I tried), despite the published specs of the said power amps saying that 2.0V = full volume or similar. With most of these power amps, I can gain more volume by using a matching preamp. 

 

Something is wrong.  Measurements will show.    I would bet (becuase you've tried multiple amps) the NADAC is not outputting the voltage you expect it is - so it's either misconfigured or faulty.

[davewantsmoore]

On 10/17/2017 at 1:51 PM, Primare Knob said:

https://www.minidsp.com/products/usb-audio-interface/u-dac8

 

Came across this one today. Cheap enough to fool around with. It does have a rather hi-ish output impedance. So I'll doubt it will do good driving a power amp directly.

 

As long as your amplifier input impedance is high ... and your gain structure is good.... then it will be fine.

[Keith_W]

6 hours ago, roh008 said:

So next question, if all of my music collection is not DSD native, but the DAC supports DSD, is their audible benefit to up-sample and convert it?

Also some great insight from @CryptiK on what fan options, I scratched the surface when looking at changing the fan on my water-cooling pump, and started to come across what you wrote about. I might have to inbox box you if you don't mind, as I'm looking to replace my kuhler radiator fan to a quieter one.

 

Thanks Roh! 

 

1. Is there an audible difference? I think there is. You can come and listen and decide for yourself. 
2. Don't ask me anything about radiators please! I haven't done enough research yet. At the moment I am thinking of two EKWB 360 radiators (i.e. 180mm fans x 2 per radiator, total of two radiators), each with slow spinning fans. I have no idea how much noise this will make because I haven't bought the things to try. 

 

6 hours ago, davewantsmoore said:

 

Something is wrong.  Measurements will show.    I would bet (becuase you've tried multiple amps) the NADAC is not outputting the voltage you expect it is - so it's either misconfigured or faulty.

 

I'm sure there is something wrong. I don't have a voltmeter or an oscilloscope so I can't test it myself. 

[davewantsmoore]

6 hours ago, roh008 said:

So next question, if all of my music collection is not DSD native, but the DAC supports DSD, is their audible benefit to up-sample and convert it?

 

Yes, possibly.... depends on the details of what's going on with your DAC.

 

Many DACs work by converting everything to DSD (or similar) ... and so bypassing this conversion could be helpful if done the right way.