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DSD DAC + Hypex modules = digital amplifier?


bibo01

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I would like to receive some technical information on the possibility of building a digital amplifier, As I do not have direct experience with both main components - digital input and Hypex modules.
The idea would be to use some form of DSD DAC working in DSD only (or more correctly, in PWM) and send that signal to Hypex modules (NC500 type).
Is it possible? What is this link made of? @Miska
Wanting some volume control, how can it be implemented apart from a server?

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Three comments:

 

Class D amps are not "digital" amps. They are switching amps. The "D" is only the designation as a coincidence, as it was the next alphabet letter in line as amp "classes" were named. 

 

Hypex modules are setup for analog input.

 

If you are actually talking about something different, which is a pure PWM setup then what I think you really need to look at is some kind of "Power DAC" there are DACs on the market that convert everything to PWM and then just filter the output to produce analog output. I don't know of any device you can buy as a consumer that just converts everything to PWM and then is sent to a parallel device that adds amplification to the PWM stream. 

 

The closest commercial thing available is probably the NAD digital amps and power DACs. 

Main listening (small home office):

Main setup: Surge protector +>Isol-8 Mini sub Axis Power Strip/Isolation>QuietPC Low Noise Server>Roon (Audiolense DRC)>Stack Audio Link II>Kii Control>Kii Three (on their own electric circuit) >GIK Room Treatments.

Secondary Path: Server with Audiolense RC>RPi4 or analog>Cayin iDAC6 MKII (tube mode) (XLR)>Kii Three BXT

Bedroom: SBTouch to Cambridge Soundworks Desktop Setup.
Living Room/Kitchen: Ropieee (RPi3b+ with touchscreen) + Schiit Modi3E to a pair of Morel Hogtalare. 

All absolute statements about audio are false :)

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28 minutes ago, bibo01 said:

Yes, I am thinking of a pure PWM setup.  I tried to mention it in my OP, probably confusingly. 

 

I am not too familiar with NC500 Hypex modules, but I know they work in PWM.

So, are you saying that they only accept analog input?

If that is the case, it would not be possible to make a purely digital amplifier... 

 

My understanding is that if you buy the NC500 module, you need to use a Hypex input buffer or add one of your own. So it's not sold to the DIY market, or isn't designed to be.

No complete NC500 based amps that I've seen are designed with digital inputs. Again, what you are talking about - a PWM amp/DAC - is being done by NAD and I think Lyngdorf. It's not a trivial exercise. 

Main listening (small home office):

Main setup: Surge protector +>Isol-8 Mini sub Axis Power Strip/Isolation>QuietPC Low Noise Server>Roon (Audiolense DRC)>Stack Audio Link II>Kii Control>Kii Three (on their own electric circuit) >GIK Room Treatments.

Secondary Path: Server with Audiolense RC>RPi4 or analog>Cayin iDAC6 MKII (tube mode) (XLR)>Kii Three BXT

Bedroom: SBTouch to Cambridge Soundworks Desktop Setup.
Living Room/Kitchen: Ropieee (RPi3b+ with touchscreen) + Schiit Modi3E to a pair of Morel Hogtalare. 

All absolute statements about audio are false :)

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13 hours ago, bibo01 said:

I would like to receive some technical information on the possibility of building a digital amplifier, As I do not have direct experience with both main components - digital input and Hypex modules.
The idea would be to use some form of DSD DAC working in DSD only (or more correctly, in PWM) and send that signal to Hypex modules (NC500 type).
Is it possible? What is this link made of? @Miska
Wanting some volume control, how can it be implemented apart from a server?

 

Great idea ;)

 

The Hypex modules include their own A/D interface. All you need is to switch the power transistors with the DSD signal ... and then there is that very very pesky RF that the power 22 Mhz transmitter is going to give off...

Custom room treatments for headphone users.

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10 hours ago, firedog said:

Three comments:

 

Class D amps are not "digital" amps. They are switching amps. The "D" is only the designation as a coincidence, as it was the next alphabet letter in line as amp "classes" were named. 

 

Hypex modules are setup for analog input.

 

If you are actually talking about something different, which is a pure PWM setup then what I think you really need to look at is some kind of "Power DAC" there are DACs on the market that convert everything to PWM and then just filter the output to produce analog output. I don't know of any device you can buy as a consumer that just converts everything to PWM and then is sent to a parallel device that adds amplification to the PWM stream. 

 

The closest commercial thing available is probably the NAD digital amps and power DACs. 

My Lyngdorf TDAI2200 works as you described. Also the new model, with USB input.

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11 hours ago, firedog said:

 

If you are actually talking about something different, which is a pure PWM setup then what I think you really need to look at is some kind of "Power DAC" there are DACs on the market that convert everything to PWM and then just filter the output to produce analog output. I don't know of any device you can buy as a consumer that just converts everything to PWM and then is sent to a parallel device that adds amplification to the PWM stream. 

 

The closest commercial thing available is probably the NAD digital amps and power DACs. 

 

Is this the same concept as the "NoDac" discussed on DIY Audio, or Miska's DSC DAC?  In other words a chipless DSD DAC to be used in conjunction with HQP etc doing the DoP.

 

If so I'd be really interested in knowing what DACs (not amplifiers) are out there as finished products on the market now.  Didn't seem much (T&A, Lampi, Mivera maybe?) when I last asked.

 

 

 

 

 

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Does the LUMIN M1 fit in this category?

I asked them if the M1 has the same dac as the D1 and they said it doesn't have a DAC?

 

HUH?  YOU have to have a dac??

 

EXCERPT OF THEIR RESPONSE TO ME::::::::

 

The LUMIN M1 has the same playback feature as the D1, but there is no DAC in the M1. M1 uses a advance digital processor to directly drive a pair of speaker. There is no line level analog output on the M1.

The M1 uses advance audiophile grade clock and galvanic isolation on the network connector.

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DSD is special because it's essentially an analog waveform. But here's the thing -- DSD runs at least at 2.8 MHz. Class D amps run at 400-500 kHz. Technics' GaN FET amps runs at around double that -- there are literally two amps in the world at this time which use it. So direct-digital is by no means a 1:1 translation from the digital domain to the analog.

 

Also, it is widely understood that 2.8 MHz is too low, and that DSD256+ (12 MHz) pushes noise shaping artifacts sufficiently far enough down the ultrasonic band.

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1 hour ago, GUTB said:

Also, it is widely understood that 2.8 MHz is too low, and that DSD256+ (12 MHz) pushes noise shaping artifacts sufficiently far enough down the ultrasonic band.

 

Well, it depends on what you compare against. Traditional Class D amps tend to put out quite a bit more noise than DSD64 DACs...

Signalyst - Developer of HQPlayer

Pulse & Fidelity - Software Defined Amplifiers

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6 hours ago, MikeJazz said:

My Lyngdorf TDAI2200 works as you described. Also the new model, with USB input.

Yes, I suggested that in my next post. The OP seemed to be looking for a DIY solution though. 

Main listening (small home office):

Main setup: Surge protector +>Isol-8 Mini sub Axis Power Strip/Isolation>QuietPC Low Noise Server>Roon (Audiolense DRC)>Stack Audio Link II>Kii Control>Kii Three (on their own electric circuit) >GIK Room Treatments.

Secondary Path: Server with Audiolense RC>RPi4 or analog>Cayin iDAC6 MKII (tube mode) (XLR)>Kii Three BXT

Bedroom: SBTouch to Cambridge Soundworks Desktop Setup.
Living Room/Kitchen: Ropieee (RPi3b+ with touchscreen) + Schiit Modi3E to a pair of Morel Hogtalare. 

All absolute statements about audio are false :)

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18 hours ago, Norton said:

Is this the same concept as the "NoDac" discussed on DIY Audio, or Miska's DSC DAC?  In other words a chipless DSD DAC to be used in conjunction with HQP etc doing the DoP.

I think NoDAC may be similar in that the analog filter following the DSD stream would likely be passive — assuming the DSD stream is directly amplified. 

 

The point is that the DSD stream could be directly amplified without being transcoded. 

Custom room treatments for headphone users.

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12 hours ago, firedog said:

Yes, I suggested that in my next post. The OP seemed to be looking for a DIY solution though. 

 

DIY as in using Hypex modules? 

They aren’t suited to direct DSD for several reasons: 1) frequency is way to low 2) depend on analog feedback loop 

Custom room treatments for headphone users.

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10 hours ago, bibo01 said:

What are potentially suitable modules? (If you are allowed to say it)

I don’t know of a module that is commercially available. 

 

Without knowing implementation details, I have heard that Estelon implements something like this into active speakers.

Custom room treatments for headphone users.

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