Phasure NOS2

[PeterSt]

Hi Matt,

Nah, impossible. This has been the original plan though. The design is so complex that by now it is already almost a year later than originally planned. But at least it's now in a stage that I think all is consistent and can (get to) work.

The means the D/A is done is completely new and therefore highly suspect to overlooking things ... which happened several times. I think it was last September that I was in the order screen to have one of the (raw) PCBs produced when I saw such a thing "not for the better". That PCB today still hasn't been produced because I now like to wait for the result of that other one due. If that does not work out, the one I just talked about must change a little plus it will be back to the drawing board for the one now due. And that one too is based on a new concept as far as I can tell ...

Peter

[PeterSt]

So ...

When you use a fairly normally sized monitor, you see an about 1:1 scaled screenshot of "something" of the first PCB, which will be here next week. Say that this is the most physical product I have at this moment because it's the confirmation of the (Chinese) company of how the so-called solder mask sheet is going to look like.
A solder mask sheet is an (in this case) metal laser cut sheet with holes in there and if you overlay it on the PCB under/in the holes you see the soldering pads of the PCB.

But now guess what this sheet is for in our case ...
(just shoot)

Anyway, this first PCB to really put to getter is for a fully differential power amplifier (an amplifier with two voltage sources both working in opposite direction, with very good common mode noise rejection and "no 2nd harmonic" exhibit).

The THD+N should be better than 0.00003% but how much better is yet to see (and measuring it could be a problem).
And yes, this is a power amplifier and it does ~52Watts into 8Ohm.
The gain will be 18 which is just about right for everyone but the 52W can of course not bear too inefficient speakers but normally it will do and for an SPL of about 100.
Slew Rate is 1950V/us ().

If this works out it could be the best amplifier ever, that is, looking at the distortion figures only (but then it should sound the best as well). And notice that this is not stupid Class D, so no HF sh*t  either.
Also it will be a "cold" amp, or IOW if you don't use it or play softly, it will hardly consume power.

While this is to be a great power amplifier, we're still talking D/A converters. Now 8 of these can be in there, max ...


For your fun, and looking at this part of the DAC only, try to envision how huge the heat problem is, and how much time it takes to find setups which can dissipate sufficiently. Meanwhile I am still so that I want the heat in the cabinet to be very low *and* consistent. Especially the latter is of crucial importance. Just think about how resistances will vary when the heat varies (bad for D/A converters !).
Now think that I can easily work for a month to find good solutions for such a problem. Really so !

What's also problematic (but I create the problem myself) is that I like to have linear power supplies. This is not easy at all when so much power is required (so think x8). And, not sure yet if I am going to make it with that, but at this moment it looks like it is going to work (power supplies will be in a separate cabinet anyway, which btw implies its own problems with high currents).

Btw, the modularity is already visible here;
Envision that each of the large squares contributes to the current needed. Now, I may need maybe 8W of power only. So I also need only a fraction of those black squares. And the design is so that we can just leave out what is not needed.
Or :
I may need that 8W for my woofers and I need 0.5W for mid and even less for the tweeter. And thus in my own DAC each module (in pairs - stereo) will be (or can be) different.

But first it must really work.
(first parts for it arrived yesterday and the remainder upcoming Tuesday and then ... )

Peter

[Matt]

Very impressive, Peter,

can you tell us something about how this design handles DSD?

Thanks

Matt

[Mamba315]

Do you know the output impedance for the amps?

[juanpmar]

Peter, it is being difficult for me to follow you. A new amp? for what? to replace the Gainclone you use with your Orelo? Those amplifiers would be included in the NOS1 chassis or I am wrong?
What is the ultimate goal of these new projects? I do not speak about to get a better sound but about what kind of system configuration you are looking for. A simple squeme would help.

Sorry in case I´m not understanding anything, you know that I am of those who have the hardest head with respect to the technical side.

Regards,
Juan

[PeterSt]

Take it easy guys. I know it looks intrigueing but it may be that because I'm not posting everything at once. So here and there, with some spare time, I'll put up things. And think that maybe 100 posts are required to describe basics without answering questions.
But of course, ask what you like !

Peter

[PeterSt]

Do you know the output impedance for the amps?

Hi (other) Matt,

It is rated to drop to 3 Ohms for the power (current) it will handle (read : the heat it can dissipate).
Notice that this (3 Ohms) anticipates normal drivers which will be 4 Ohms or a little less *and* that this DAC is also all about cross overs. So no elements will be in your speaker to let drop the DC resistance of the driver (as the only device in the speaker).
Otherwise think like the resistance dropping the more current will flow (in linear fashion) *if* the power is to be the same. However, I think that the lowest resistance will happen in the highest frequencies and the highest frequencies (tweeter) relatively don't require power. So for easy thinking : suppose that first the tweeter requires 26W (RMS) only but it is rated to drop to 1.5Ohms, then the heat dissipation is still the same and nothing is the matter.

Something else is that the heat dissipation depends on the heat sinks which are going to be taylor made - can be as large as required because of that *and* will be at the outside of the cabinet (thus no heat build-up inside anyway).

Btw, the (max 8 channel) power amplification itself is an option. Besides that, it is an option per channel. So for example, you could use (also XOver-filtered) power amplification for mid and high and use line out for 2x bass (e.g. with different delay on each channel).

The reason for the integrated power amplification is that now you'll have access to 8 channels of the highest quality at a relatively affordable price (with the notice that us guys often are not an exception in using 10K costing 2 channel amps).
And the "highest" quality doesn't mean "for the price" but just the best I could think of for design and real practice. Anyway the specs tell me so.
And that we can avoid always detrimental interlinks is something else.

And oh, as a bonus you can "cascade" two of these DACs, one for the left channel and one for the right channel and now you have 16 channels. For now this is sorted out theory which can work (each DAC about "in" the speaker and both synchronized) but it is a bit crazy. This means :
... That we are not planning smaller cabinets which could contain e.g. 3 channels per (L/R) side just because it would be better to have the DAC very close to the speaker (very short LS cables). Thus for example there will be a main board and this main board can take 8 channels; We are not going to make a small main board so we can have a perceived less costing DAC in two separate cabinets. Thus, this is not cheaper at all - only more expensive.

Regards,
Peter

[AlainGr]

I agree with Juan... At this point we do not have sufficient data to really understand, apart from a multichannel dac and maybe electronic crossovers (?), with the needed power amplifier(s)...

At this point I am clueless... But a schema of the placement of the components would help maybe...

Alain

[vrao]

As Alain,

I suspect a multichannel amp/DAC with crossover and DSP or ASP 

VJ

[Matt]

Peter,
a short question only:

Is this the DAC you mentioned here and on the CA forum, which gets running DSD256 and PCM256 through the same hardware?

Matt

[AlainGr]

Peter, do you have a "hand extinction"

[christoffe]

And oh, as a bonus you can "cascade" two of these DACs, one for the left channel and one for the right channel and now you have 16 channels. For now this is sorted out theory which can work (each DAC about "in" the speaker and both synchronized) but it is a bit crazy.

A Dutch company ............... .

http://www.grimmaudio.com/hifi-products/loudspeakers/ls1/


Joachim

[brunok]

Hi Peter:
Tell me if I'm on the right track with the new DAC/amplifier by way of this example.  Say I wanted to build my own speakers with three drivers in each:  tweeter, woofer, subwoofer.  I know the new DAC allows for 8 channels but my example above would only require 6 (3 X 2) channels.  The DAC along with a hardware DSP/crossover (presumably adjusted somewhat with software) would allow me to set the crossover frequencies digitally (primarily)as opposed to what I have seen by others done in analog.  Add to that the ability to amplify each driver separately up to 52W giving me a unified/integrated system.  Presumably the system is designed like this to enhance the overall sound quality. So fewer or shorter length cables, closer proximity to the drivers, hardware digital adjustments vs analog, external linear power supply, etc., all add up to a "No Holds Barred" NHB approach to the best sound quality you can come up with.  You stated the THD to be 0.00003% which is pretty incredible and I look forward to finding out other distortion characteristics and such as you give us more info along the way.
Would you say these amps are at least as good if not better than the gainclones in the Orelo MKII's?  Also I note that you mention that the system is modular meaning one could start with 2 channels and later add on up to 8 channels. So in my example above if I wanted to double up the channels to give more power to the subwoofer, I could do so (adding up to in total 8 channels with the subs @ 100dB+).  Not only that but on each channel itself I can choose how much power (up to 52W) I want to go to each driver.  So the tweeters obviously would need less power than the subs, requiring less from the linear power supplies resulting in "purer" sound. The one proviso is that the speaker or driver(s) should preferably be at 100dB or higher efficiency to benefit from this integrated approach.  Am I roughly on track or off base?!

Regards,
brunok

[brunok]

oops, 100W+ not dB.
TNX

[Matt]

Peter,
a short question only:
Is this the DAC you mentioned here and on the CA forum, which gets running DSD256 and PCM256 through the same hardware?
Matt

Peter,
please, a short answer. YES or NO. Thanks
Matt