Multi-Channel, Multi-Amplifier Audio System Using Software Crossover and Multichannel-DAC

[dualazmak]

In my first post #1, I just added one paragraph of;

In this thread, I also would like to share and discuss these major issues always associating with Multi-Channel, Multi-Amplifier Audio System;
- Digital I/O for software crossover within PC
- Delay, latency and synchronization issues
- Phase issues
- Master volume and gain issues
As you may well aware, these issues are somewhat interdependent with each other.

 

[dualazmak]

Pavel of OKTO kindly contacted me today informing my DAC8PRO Black (order #106) will depart Prague by FedEx Express Package on May 4 Monday together with my paired Apple Remote Controller. Hopefully, it will arrive here, Chiba Prefecture in Japan, by the end of the week.

Pavel also sent me the fully compatible ASIO driver installation package for which Burning Sounds also kindly informed in this thread.

 

[John1959]

Hi dualazmak,

yes, good idea.

This is the DSP-DAC-AMP setup schema with the FA modules.
View attachment 59774

And this is what I hope will be left after I have installed the modules at the back of my speakers and got rid of my AVR and Bluray player (I think I will put the devices into the adjacent stairway to our basement and control them via an IR extender; the coax cable will disappear in bookshelves, the subwoofer cables in ducts):
View attachment 59775

Hi Nabussan,

I see in your setup you use Bridge Tied Load (BTL) for the subwoofer to get 500W/8ohm instead 2x125W/8ohm from that plate amp. I probably also will use BTL in my system. I ordered a Nord 8-channel amp with several nCore modules. From the Hypex datasheet I learned that the voltage gain will be 6dB in this mode (a rather high 32 dB instead of 26 dB). That's to be expected of course.

I wonder if I have to compensate for that in the DSP (taking the BTL-channel 6 dB down relative to the other channels), besides the phase inversion of one channel. Do you know about that? Or maybe someone else?
Thx

John

 

[dualazmak]

Hello friends,

I assume everyone here is curious about my fascinations and enthusiasms on YAMAHA NS-1000 (not NS-1000M) and its SP units. Even though you can find so many review articles on NS-1000 and NS-1000M, here let me just inform you one rather recent review article;
https://www.hifinews.com/content/yamaha-ns-1000m-loudspeakers
https://www.hifinews.com/content/yamaha-ns-1000m-loudspeakers-page-2
https://www.hifinews.com/content/yamaha-ns-1000m-loudspeakers-sidebar-family-values
https://www.hifinews.com/content/yamaha-ns-1000m-loudspeakers-lab-report

The SP units are common for NS-1000 and NS-1000M. Little people knows, however, the difference between NS-1000 and NS-1000M; there are considerable differences in enclosure thickness and weight;

As described in my previous post, I have fully renovated the SP terminals and LC-network+attenuators of my NS-1000 to be ready for this multi-channel, multi-amplifier project.

Edited to add at 23:30 May 4, 2020 Japan time;
One of my audio-enthu friends in Japan kindly informed that these two links are also nice for your kind notice on NS-1000 and NS-1000M;
http://www.troelsgravesen.dk/Yamaha-NS1000.htm
http://www.thevintageknob.org/yamaha-NS-1000.html

Edited to add at 08:22 July 5, 2020 Japan time;
https://liquidaudio.com.au/legendary-yamaha-ns-1000m-loudspeaker-review/

 

[dualazmak]

Hello friends,

As I showed in my first post, I will use my OPPO Sonica USB DAC+single-ampilifier (ACCUPHASE E-460) as my reference sound system throughout the progress in this project. Just in very nice timing, amirm recently reported a very nice review and detailed measurements of OPPO Sonica USB DAC. I just posted my appreciations and comments in that review thread.

 

[dualazmak]

My DAC8PRO is on the way to my home. Yes, I can wait!

I hope it will be smoothly loaded onto FedEx air cargo at Charles De Gaulle AP. I once had very bad experience at Charles De Gaulle that the entire airport was suddenly shutdown, including the escalator operation, just 3 min before my boarding to a flight to Innsbruck because of the general strike of French Labor Union....

 

[Sal1950]

Great thread! Don't believe I'll ever take my multich rig to this level but never say never, you never know. LOL
This thread should be enlightening and educational for our member's and also bring in some feedback for you.
Good luck on the journey!
Sal

 

[dualazmak]

Great thread! Don't believe I'll ever take my multich rig to this level but never say never, you never know. LOL
This thread should be enlightening and educational for our member's and also bring in some feedback for you.
Good luck on the journey!
Sal

Hello Sal1950 and friends,

Sal, thank you for your encouraging post! This thread is also educational for myself, too. I will move forward step-by-step even after the arrival of my DAC8PRO which is now onboard on FedEx air cargo flying over Russia.

After the arrival of DAC8PRO, I would like to firstly very carefully compare the overall sound quality of OPPO Sonica DAC (ES9038Pro) and DAC8PRO (ES9028Pro) in stereo L&R 2-channel mode using exactly the same single-amplifier system in up to 2xDSD format through ASIO drivers. Fortunately, my ACCUPHASE E-460 integrated amp has two balanced XLR inputs, and they can be easily switched by a remote controller. (I may repeat the comparison trials four times to check all of the 8 channels of DAC8PRO).

I may also compare the sound of DAC8PRO and SONICA DAC in 192 kHz 24 bit format using the same single-amplifier system and software crossover EKIO as flexible channel distributor. I have already prepared EKIO's configuration file for such comparative listening sessions. (I will not, of course, go into detailed measurements of DAC8PRO, since amirm already reported the in-depth thorough review of DAC8PRO.)

I would like to share my impressions (subjective results with my ears+brain) of such comparisons in this thread soon, and your visit and participation will be much welcome.

After I would fully recognize/understand/complete the sound and burn-in of each of the 8 channels of DAC8PRO, I will move forward into the planned multi-channel multi-amplifier system using DAC8PRO, always having the Sonica DAC+single-amplifier as my reference sound.

As shown in my post #55, I will firstly confirm and test the 8-channel operation using completely independent 8 amplifiers, i.e. using two of YAMAHA XM4080 which has volume in each channel being nice to simulate the gains as to present attenuator settings for SQs (squarkers), TWs (tweeters) and STs (super tweeters). I will place my order for two of YAMAHA XM4080, however, after I would actually see the face of DAC8PRO by my eyes at my home hopefully very soon.

After the completion of multi-8-channel multi-8-amplifier trials with EKIO, DAC8PRO and XM4080 (two), I will further move forward to my current ultimate(?) goal of rather Hi-Fi multi-amplifier system; as also shown in my post #55, I am very much interested in NORD Acoustics' configurable 8-channel amplifier Nord One MP NCXXX 4-8 122-500W;
https://www.nordacoustics.co.uk/pro...w-custom-configurable-channel-amplifier-black
with;
Channels 1-2: NC252MP (2x250W 4Ohm, 2x200W 8Ohm)
Channels 3-4: NC122MP (2x125W 4Ohm, 2x75W 8Ohm) or NC252MP (2x250W 4Ohm, 2x200W 8Ohm)
Channels 5-6: NC122MP (2x125W 4Ohm, 2x75W 8Ohm)
Channels 7-8: NC122MP (2x125W 4Ohm, 2x75W 8Ohm)

I am now gathering various info on Hypex Ncore amp modules, NCxxxMP series and Nord One MP NCXXX 4-8 122-500W. Any suggestion, information or comment for utilization of Nord One MP configurable multi-amplifier in this kind of multi-channel system, therefore, will be very much appreciated.

 

[John1959]

Hello Sal1950 and friends,

(...)

After the completion of multi-8-channel multi-8-amplifier trials with EKIO, DAC8PRO and XM4080 (two), I will further move forward to my current ultimate(?) goal of rather Hi-Fi multi-amplifier system; as also shown in my post #55, I am very much interested in NORD Acoustics' configurable 8-channel amplifier Nord One MP NCXXX 4-8 122-500W;
https://www.nordacoustics.co.uk/pro...w-custom-configurable-channel-amplifier-black
with;
Channels 1-2: NC252MP (2x250W 4Ohm, 2x200W 8Ohm)
Channels 3-4: NC122MP (2x125W 4Ohm, 2x75W 8Ohm) or NC252MP (2x250W 4Ohm, 2x200W 8Ohm)
Channels 5-6: NC122MP (2x125W 4Ohm, 2x75W 8Ohm)
Channels 7-8: NC122MP (2x125W 4Ohm, 2x75W 8Ohm)

I am now gathering various info on Hypex Ncore amp modules, NCxxxMP series and Nord One MP NCXXX 4-8 122-500W. Any suggestion, information or comment for utilization of Nord One MP configurable multi-amplifier in this kind of multi-channel system, therefore, will be very much appreciated.

Today I received my 8-channel Nord (Hypex) amp. Same as you described above, except channel 1-2 is a NC502MP (2x500W 4 Ohm) module. All other channels are NC122MP. Note that I had a slight preference for the NC252MP for channel 3-4, but this popular module is out of stock and will not become available soon because the Malaysian factory is in lockdown. Even Hypex don't have them anymore. Anyway, I can also bridge two NC122MP modules because this amp is meant for a 3 way system.

See picture below for the internals. I think they did a nice job. Case is basic of course but that's expected and fine to me. No phase reversals at the output terminals as far I can see! There were some issues.

Note that one NC122MP module has blue capacitors near the output filter coils instead of the brown ones on all other modules.

John.

 

[dualazmak]

Today I received my 8-channel Nord (Hypex) amp. Same as you mentioned above, except channel 1-2 is a NC502MP. All other channels are NC122MP. Note that I had a slight preference for the NC252MP for channel 3-4, but this popular module is out of stock and will not become available soon because the Malaysian factory is in lockdown. Even Hypex don't have them anymore. Anyway, I can also bridge two NC122MP modules because this amp is meant for a 3 way system.

See picture below for the internals. I think they did a nice job. Case is basic of course but that's expected and fine to me. No phase reversals at the output terminals as far I can see! There were some cases.

Note that one NC122MP module has blue capacitors near the output coils instead of the brown ones on all other modules.

John.

Hello John1959,

Thank you for your timely info on 8-channel Nord (Hypex) amp which is very much attractive for me too.

I agree with you that we should carefully check and confirm the SP cable connections inside the case especially in these multi-channel amplifiers. I do hope that the Malaysian factory would back in normal production by the time I will place my order for Nord One MP NCXXX 4-8 122-500W.

I am very much looking forward to hearing your review and/or report on DAC8PRO+8-channel Nord (Hypex) amp in this thread or other places. I also wonder if you could hear the difference in sound between the blue capacitor module and brown ones, even though I assume no difference.....

 

[dualazmak]

Ｍy DAC8PRO (order #106, February 15), together with paired Apple Remote controller (order #112, February 29), has just arrived at my home today May 9 Japan Time. I will soon, hopefully within a week or two, start to share and report my experiences in this thread. My rather relaxed days under COVID-19 "stay-home" consensus, however, will end-up tomorrow May 10 Sunday, and my posts will be somewhat slow down from now on....

 

[dualazmak]

DAC8PRO:

 

[dualazmak]

DAC8PRO:

 

[dualazmak]

DAC8PRO:

 

[dualazmak]

Hello Friends,

DIYINHK V4.59.0 ASIO Driver for DAC8PRO, and 2xDSD play by JRiver, etc.

Before to connect DAC8PRO to PC by the attached USB2.0 cable, I installed the ASIO Driver Package,
DIYINHK_UsbAudio_v4.59.0_2019-02-28_setup.exe
which Pavel of OKTO kindly sent me last week.

Then I connected DAC8PRO to PC by USB 2.0 cable, and Windows 10 recognized it as a DIYNHK USB Audio device;

In JRiver, we can choose DIYINHK ASIO Driver (ASIO) and set it to 2xDSD in native format;

 

[dualazmak]

I first compared the overall sound quality in 2xDSD (DSD128) native format through DAC8PRO (ES9028PRO) and OPPO SONICA DAC (ES9038PRO) using exactly the same single-amplifier system as shown here;

The out put level of the two DACs were carefully set in exactly the same using the E-460's VU meter and several tracks of the "Super Audio Check CD". In this case, DAC8PRO's CH-1(L) and CH-2 (R) were used for DA process.

Even though I have not yet fully burnt-in DAC8PRO, the overall sound quality of DAC8PRO is really wonderful as fully measured and reported; now I feel SONICA DAC's sound is a little bit over-tuned by OPPO's color or smell, and found DAC8PRO's sound is slightly but significantly more natural, clear and better in 3D perspectives; really super nice, more than expected.....

 

[dualazmak]

DAC8PRO vs. OPPO SONICA DAC Overall Sound Quality Comparison in 192 kHz 24 bit using EKIO as channel distributor

Then I tried and tested DAC8PRO's each of the 8 channels in 192 kHz 24 bit using EKIO, and compared the overall sound quality with SONICA DAC also in 192 kHz 24 bit.

For this purpose, I prepared EKIO configuration (as channel distributor) under ASIO4ALL I/O as;

Here, JRiver is playing music tracks into ASIO4ALL, so the I/O routing is;

JRiver --> ASIO4ALL --> VB Audio Hi-Fi Cable ASIO --> EKIO --> ASIO4ALL --> DIYHNK ASIO --> each of 8-channels of DAC8PRO --> E-460 amp
simultaneously together with;
JRiver --> ASIO4ALL --> VB Audio Hi-Fi Cable ASIO --> EKIO --> ASIO4ALL --> OPPO ASIO --> OPPO SONICA DAC --> E-460 amp

SONICA DAC's L & R balance XLRs are going into E-460's BAL1,
and
DAC8PRO's CH-1(L) & CH-2(R) balance XLRs are going into E-460's BAL-2,

so that I can easily select and listen either of them by E-460's remote controller; BAL-1 or BAL-2.

With this comparsion in 192 kHz 24 bit, as usual the overall sound quality is very nice for both of them, and I again found that DAC8PRO's sound is slightly but significantly more natural, clear and better in 3D perspectives; really amazing!

 

[dualazmak]

DAC8PRO's Any Pair of 8 channles; Overall Sound check in 192 kHz 24 bit using EKIO as channel distributor

I also compared or checked any 2 pairs of DAC8PRO's 8 channels in 192 kHz 24 bit using the EKIO distribution configuration shown in the previous post, i.e. simultaneously same sound in identical gain in each of the 8 channels, and the BAL-1, BAL-2 inputs into E-460 as shown below;

I found and confirmed that there is no difference in overall sound quality between any of the 8 channels, of course(!) as expected. The overall sound is always amazingly nice....

 

[QMuse]

I also confirmed that REW-Wavelet analysis is also very much useful to "see" the listening room acoustic environments;
View attachment 58170

This looks ok, but if you really want to check if the delay is set to correct value you should make phase measurement and see if there is a phase mismatch at crossover points.

It would also make sense to check if impulse responses of sub and main are time aligned.

 

[dualazmak]

Conclusions after Day-1 trials, comparison and check with DAC8PRO

1. Absolutely nothing wrong with my DAC8PRO. It is working perfectly fine, as expected.

2. In very careful comparison of overall sound quality between OKTO DAC8PRO and OPPO SONICA DAC, I found and confirmed that DAC8PRO's sound is "slightly but significantly" more natural, clear and better in 3D perspectives as well as S/N, even though I have not yet fully burnt-in the newly arrived DAC8PRO.

3. I could check and confirm that there is no difference in overall sound quality between any of the DAC8PRO's 8 channels, of course.

4. Software crossover EKIO can properly allocate any of the crossovered channels into any of the DAC8PRO's 8 channels, in full ASIO routing of 192 kHz 24 bit signal.

5. Now, I can fully agree with the amirim's in-depth objective review, and Halfway Tree's short but very nice, rather subjective review.

Amirm wrote there at conclusions, "Okto Research DAC8 is an incredibly well designed and featured product. It is my absolute pleasure to recommend the DAC8. ". Let me just join his conclusions.