Topping D900 DAC Review

[Sir Sanders Zingmore]

The, “standard,” line out volume, minimum, you’ll get out of basically all devices on the market with balanced out is ~4V. Many devices offer ~5V out as well. As voltage goes up, signal strength rises farther above noise floor, so SINAD improves.

12.3V is the absolute limit with D900 because it has an active buffer (it has a full active preamp built in); this provides sufficient drive to achieve full power output on newer power ample that have very low to zero gain (unity gain), which achieves the absolute lowest full-chain noise floor possible. They’re doing this on many of their newest DACs; the E50 II goes over 11V on High Amplitude setting.

-Ed

Sorry maybe I didn’t word my question well.
I’m trying to understand why one set of measurements seem to show a SINAD of 122.5 at 4.1v and that same set of measurements also says 5v.

And then why neither 4.1v or 5v corresponds to a SINAD OF 122.5 on the chart that follows.

 

[staticV3]

I'm confused (which is usually my misunderstanding so hopefully someone can clarify for me)

I read these measurements as saying that at 4.1 Vrms the DAC has SINAD of 122.5 dB
But in small print under the 122.512dB measurement it says 5Vrms

5Vrms in small print is the APx555's current input voltage range (like on your multimeter).

The D900 measured 122.5dB SINAD at 4.1Vrms output in the first graph.

And then I see in the below chart that 4Vrms corresponds to a SINAD of ~117db and 5Vrms looks like about 119dB.

What am I missing?

In the second graph where Amir did a SINAD vs level sweep, the D900's internal volume was changed from -2dB to +8dB, which likely affected its output some, so that it no longer matched the first graph.

 

[nanook]

I know that Lake People/Violectric also repairs devices over 20 years old at reasonable prices, and they are based in Germany.
So it doesn't seem to be too difficult.

Old gear can be repaired almost infinitely. Most of my lab gear is from the 1970s (mostly TEK and HP). So far it was always possible to restore the functionality.

- Standard ICs (you might need an adapter-PCB to fit the up-to-date packages). For obsolete ICs that are a bit special you can still source them at a broker or eBay. Even if there's a microcontroller with EPROM involved you can replace the uC and copy the EPROM from a borrowed unit.

- Electrolytic caps, through-hole got smaller with the same ratings - easy to fix

- Electromechanic stuff that broke usually is the hardest challenge if you want to restore the original appearance.

I'm working in the electronics lab of a university. One of our tasks is to repair broken equipment.
When people bring in stuff from the last century we can usually bring it back to life (maybe a controller for some ion-getter pump; a new pump incl. controller would be beyond 10k Euro such that it's worth the effort to get the controller up again)
When people bring in relatively new units having microcontrollers with on-die FLASH, we can check the power-supply circuits and the periphery, but if the uC gets stuck, the unit either goes to the manufacturer or into the waste- bin in case there's no service available anymore.

Long-story-short:
Nowadays gear will eventually be difficult to repair even if the manufacturer is willing to do so if he hasn't shelved lots of spare parts like mechanical encoders, LCD displays, proprietary transformers, etc.
This may be the reason why Bryston adapted their policy.

 

[nanook]

Thank you so much for opening the case and take a pic of the innards. Do I see correctly that this thing has an SMPS for $10 on board?

These SMPS are incredibly cheap and Meanwell (although relatively cheap) is a manufacturer that I personally rate top notch.
No idea how they manage to offer quality stuff at that price.

 

[Roland68]

They are asking too much price for a device that hasn't implemented a high quality linear power supply, TCXO clock and external 10MHz clock input. I think Gustard gives justice for their higher price devices in these departments

External 10 MHz clock inputs are only necessary for synchronization in studio settings, but I don't see their use in a device like this.
The clock technology used in this DAC is slightly higher quality than conventional TCXO clocks, so using a different one would actually be a downgrade.

Linear power supplies are also long outdated. Good switching power supplies with tailored filters are cheaper, lighter, and deliver a lower noise level than more expensive, complex linear power supplies.

While I'm also a fan of Gustard devices, I wish they would use fewer components/technologies favored by the audiophile community and instead focus on the best option for each specific application.

 

[Roland68]

Old gear can be repaired almost infinitely. Most of my lab gear is from the 1970s (mostly TEK and HP). So far it was always possible to restore the functionality.

- Standard ICs (you might need an adapter-PCB to fit the up-to-date packages). For obsolete ICs that are a bit special you can still source them at a broker or eBay. Even if there's a microcontroller with EPROM involved you can replace the uC and copy the EPROM from a borrowed unit.

- Electrolytic caps, through-hole got smaller with the same ratings - easy to fix

- Electromechanic stuff that broke usually is the hardest challenge if you want to restore the original appearance.

I'm working in the electronics lab of a university. One of our tasks is to repair broken equipment.
When people bring in stuff from the last century we can usually bring it back to life (maybe a controller for some ion-getter pump; a new pump incl. controller would be beyond 10k Euro such that it's worth the effort to get the controller up again)
When people bring in relatively new units having microcontrollers with on-die FLASH, we can check the power-supply circuits and the periphery, but if the uC gets stuck, the unit either goes to the manufacturer or into the waste- bin in case there's no service available anymore.

Long-story-short:
Nowadays gear will eventually be difficult to repair even if the manufacturer is willing to do so if he hasn't shelved lots of spare parts like mechanical encoders, LCD displays, proprietary transformers, etc.
This may be the reason why Bryston adapted their policy.

I think a 5-10 year warranty is perfectly reasonable for high-quality equipment, but Bryston's 20-year warranty is simply unmanageable for a manufacturer and actually more difficult to implement these days. You've already mentioned the reasons for this. Even as a consumer, I don't see a 20-year warranty as sensible for a manufacturer.

Of course, spare parts are an increasingly big problem these days. The cost factor is particularly significant, because in addition to the cost of the required number of all the necessary components, there are also the now considerable costs for storage space (costs for floor space, shelves, electricity, heating/air conditioning, various taxes, etc.) and logistics.

Even a manufacturer like Yamaha can no longer repair expensive devices that are only a few years old.

However, some foresight in development can significantly mitigate such problems, but as long as saving 2 cents is still more important than possible repairs, only the legislature can change things through significantly stricter laws and penalties.

 

[nanook]

However, some foresight in development can significantly mitigate such problems, but as long as saving 2 cents is still more important than possible repairs,...

Absolutely. When I worked for a small company designing and manufacturing measurement amplifiers, we strictly tried to avoid specialized components like regulators or components with non-standard footprints - even if their performance was significantly superior - because our products had lifecycles that did span 10 or even 20 years.

In some cases we did not have a choice, so we made sure we have stock for several years.
But this is a small company with products for a niche market in the professional segment.

In the consumer segment every cent counts unless you were successful to establish a brand that has a certain nimbus and you sell a handcrafted boutique product in the "snake oil arena".

 

[sunny7day]

Just bought this yesterday and it sounds absolute shit.

 

[SoySalsaPicante]

Just bought this yesterday and it sounds absolute shit.

Out of curiosity, what DACs have you heard that you found sounded great?

 

[Johnkeizer]

That dirt cheap, tiny smsl su1 was superb, probably due to simplicity.
My current smsl raw1 dac, fed by the smsl cd transport via I2S, also sounds very clean and clear.

 

[Roland68]

In the consumer segment every cent counts unless you were successful to establish a brand that has a certain nimbus and you sell a handcrafted boutique product in the "snake oil arena".

His name is Niimbus, or was that not a pun?

 

[nanook]

His name is Niimbus, or was that not a

Honestly, I wasn't aware of this brand
However, the price tag invites a pun

 

[sunny7day]

Out of curiosity, what DACs have you heard that you found sounded great?

M400

 

[Jcrow]

Just bought this yesterday and it sounds absolute shit.

Can you elaborate any further? What about the sound is shit?
Maybe yours is defective or something.

 

[sunny7day]

Can you elaborate any further? What about the sound is shit?
Maybe yours is defective or something.

it's brand-new

 

[Roland68]

M400

it's brand-new

The fact that the device is new has nothing to do with the possibility that the device might be defective.

I've only listened to the D900 briefly once, comparing it to other devices, and I didn't notice any difference at all.

I find the M400 somewhat questionable because SMSL only used half of the AK4499 in that device, meaning they only utilize two of the four channels. However, even back then, I couldn't hear any difference between the M400 and similar devices.

But what exactly sounds terrible about your D900?

 

[sunny7day]

But what exactly sounds terrible about your D900?

I don't know it just sounds not very good.

 

[Jcrow]

I don't know it just sounds not very good.

Maybe it’s actually a good DAC, but it’s lifted the final veil, revealing cold harsh reality. And, perhaps, you just don’t like that?
Alternatively, the DAC or your ears are not functioning as intended. I would check both.

 

[sunny7day]

Maybe i need more time to burn-in the DAC

 

[Mnyb]

Maybe i need more time to burn-in the DAC

Troll much ? Member since 2022 ?