Topping D90 Balanced USB DAC Review

[JohnYang1997]

No, there was RCA noise without the USB cable connected. With the SKW RCA interconnect pair + SKW XLR pair or RCA only there was noise. When I reconnected the USB cable that added crackling noise. Then if I added a GPU load it got really noisy.

Now there is no noise in RCA only in L / M Gain at 100% volume. In H Gain there is some very low level hum starting at 75% Gain, which I'll never hit anyway. In XLR only there is no noise or hum in H Gain 100% volume.

I'll try some cable wrapping on ferrite cores or at least clip on ferrite jackets to see if I can kill the last of that hum. I'd never heard the hum before - the rest of the noises were drowning it out. With the other noises gone now I hear that very faint low level hum at 75% Volume in H Gain.

Now I can try RCA to AMP / Speakers, probably with WBC Mogami 2534 cable - but I'll test the Mogami 2549 based cables first before deciding which to use for the longer run.

Thanks for your help and patience John

Hum for SE yes. That's more expected. I remember you were talking about some high pitched sound right? I believe those are the usb noise.
Anyway, impressive.

 

[hmscott]

Hum for SE yes. That's more expected. I remember you were talking about some high pitched sound right? I believe those are the usb noise.
Anyway, impressive.

The USB cable was removed when that Tone was heard. Now I don't hear it at all.

The hum wasn't audible before, but like I said I think the other noises were drowning out that super low level hum. There's no hum in XLR at all and in RCA it doesn't show in L / M Gain, and only shows in H Gain at 75%. That's really low level - so I can live with it, but I will still try cleaning it up over time.

I'm noticing that what I am hearing now is a lot quieter overall in XLR, and RCA is also just as quiet - I'm driving a Sennheiser HD 598cs with a 4.4mm balanced cable in L Gain A90 / D90 DAC mode.

With the heavy background noise I couldn't enjoy the RCA connection between the A90 / D90 before, now I'm noticing the RCA interconnect output level in my headphones is down a dB or so compared to the XLR interconnect position on the A90 RCA / XLR switch. I've got both XLR and RCA interconnects hooked up between the D90 MQA and A90 and switching between them. I am enjoying playback through the RCA connection right now.

 

[Gradius]

Tripp Lite USB 2.0 Hi-Speed A/B Cable with Ferrite Chokes (M/M) 3-ft. (U023-003)
https://www.amazon.com/gp/product/B008VOPCGY

Just FYI, as for USB cable I use this one (and I recommend them):
https://www.amazon.com/YB-Y1-USB2-0-Digital-Cable-Professional/dp/B01MY6NXAB

 

[EdW]

The USB cable was removed when that Tone was heard. Now I don't hear it at all.

The hum wasn't audible before, but like I said I think the other noises were drowning out that super low level hum. There's no hum in XLR at all and in RCA it doesn't show in L / M Gain, and only shows in H Gain at 75%. That's really low level - so I can live with it, but I will still try cleaning it up over time.

I'm noticing that what I am hearing now is a lot quieter overall in XLR, and RCA is also just as quiet - I'm driving a Sennheiser HD 598cs with a 4.4mm balanced cable in L Gain A90 / D90 DAC mode.

With the heavy background noise I couldn't enjoy the RCA connection between the A90 / D90 before, now I'm noticing the RCA interconnect output level in my headphones is down a dB or so compared to the XLR interconnect position on the A90 RCA / XLR switch. I've got both XLR and RCA interconnects hooked up between the D90 MQA and A90 and switching between them. I am enjoying playback through the RCA connection right now.

Sounds like you’ve had quite a fight to get this sorted out. Glad you did and I’m impressed with the helpful comments from John Yang. Great support!
To put this issue in context I’m using the stock USB cable fed from a Raspberry PI4 with RCA connection into Arcam amplifiers. Plenty of opportunities for hum from multiple grounding of the many boxes attached to the Arcams. As a check I listened to a high quality 24/96 streamed file with an exceptionally low audio level at the start of one track. No USB noise and no hum with the volume at maximum and my ear next to the speaker, only the very quiet vocals and the background hiss of the recording studio. I’m sure this is the experience most D90 users will have had.

 

[bahamot]

So I decided to upgrade my D90, now it feels and sound much better.
The remote feels flagship now with CNC aluminium construction and more tactile buttons.

 

[hmscott]

So I decided to upgrade my D90, now it feels and sound much better.
The remote feels flagship now with CNC aluminium construction and more tactile buttons.

My D90 MQA came with the RC-15A remote, with the same buttons but with a longer body to accommodate 2 - AAA batteries, I use Eneloop Pro rechargables:

The previous remote the RC-15 non-A used a CR2032 battery, here's a comparison of the battery bays between the RC-15a and RC-15:

What is the upgrade with the RC21? Does the RC 21 remote have more functionality? What kind of batteries does the RC-21 use?

 

[bahamot]

My D90 MQA came with the RC-15A remote, with the same buttons but with a longer body to accommodate 2 - AAA batteries, I use Eneloop Pro rechargables:
View attachment 77207
The previous remote the RC-15 non-A used a CR2032 battery, here's a comparison of the battery bays between the RC-15a and RC-15:
View attachment 77209
What is the upgrade with the RC21? Does the RC 21 remote have more functionality? What kind of batteries does the RC-21 use?

RC21 does not have more functionality. It has the same button layout as RC15A (D90 MQA stock remote). But it is from CNC aluminium and the buttons are more tactile than RC15A. It uses CR2032.

 

[hmscott]

RC21 does not have more functionality. It has the same button layout as RC15A (D90 MQA stock remote). But it is from CNC aluminium and the buttons are more tactile than RC15A. It uses CR2032.

I would also prefer a metal remote build, but not if it uses disposable CR2032's.

I'm always running out of those thin disposable batteries - but the AA, AAA, 21700, 26650, 18650 rechargeables I keep charged and ready to replace at any time.

I'm ok with the current long AAA powered D90 MQA remote, and I hope Topping keeps providing remotes that allow us to use rechargeable batteries in them.

 

[VeerK]

I would also prefer a metal remote build, but not if it uses disposable CR2032's.

I'm always running out of those thin disposable batteries - but the AA, AAA, 21700, 26650, 18650 rechargeables I keep charged and ready to replace at any time.

I'm ok with the current long AAA powered D90 MQA remote., and I hope Topping keeps providing remotes that allow us to use rechargeable batteries in them.

Me too, I was going to buy the aluminum remote until I realized it doesn’t use AAAs. I have an eneloop recharging station that I love too much

 

[Harmonie]

Me too, I was going to buy the aluminum remote until I realized it doesn’t use AAAs. I have an eneloop recharging station that I love too much

Don't know if rechargeable make any point here. As the current drown by either AAA or CR type cells, you may have to replace them after a couple of years or more even when used daily.
I'm also looking for this cool upgrade. I like AAA better of course, but what the heck, it's going to be hanging on next X'mas tree

 

[Pluto]

Don't know if rechargeable make any point here

Totally false economy. Even ‘Eneloop’ type cells will self-discharge a long time before even the cheapest dry cells give up.

 

[Harmonie]

Exploring the D90 now.
I have amps that trigger-on signal and do trigger-off after 15 min when no signal.
I usually leave the DAC on.
* I just noted that my amps stayed on during a couple of days though the D90 self-extinguished. Fortunately they are not class A !
I now turned the DAC off (via remote button) but my amps stay still on.
Any reason for that ? Any residential signal ?
Never happened before with former DACs 24/24 on.

 

[TonioRoffo]

Thanks. After some research, I decided to go with Hypex NC400, more expensive (that's true), but worth every penny.

NC400.... I have a pair since 2014 or so (each with their own SMPS600) and connected just about everything on them. B&W N805, 802D3, KEF ref 3, ... it's like a wire with gain really, it doesn't influence the sound of your system whatsoever. Never heard it clip, never out of stream, drives everything.

Combined it with (was then) the ideal DAC/volume control, the NAD M51. Stellar combo. Of course, nowadays you'd be fine with a Topping DAC.

 

[Harmonie]

My D90 has hum when off on the right channel only. Does anyone had similar issues ?
That prevents my mono amp to shut off.

CD transport coax > D90 > RCA > mono amps.
D90 used as preamp (XLR off).

 

[NDC]

My D90 has hum when off on the right channel only. Does anyone had similar issues ?
That prevents my mono amp to shut off.

CD transport coax > D90 > RCA > mono amps.
D90 used as preamp (XLR off).

Weird. Is it there when you take the coax cable out? And/or when you take power cable out?

 

[Scintilla]

I just received my D90 last evening and I also have hum from both channels when the unit is in standby. I will be tracing when I have some time.

This unit replaced an NAD M51, and I simply removed the NAD box and used the existing power cord and input and output cables previously connected to the NAD which exhibited no hum. I do believe the NAD has an output relay enabled in powered-on mode vs. standby. Perhaps this is the issue.

 

[hmscott]

My D90 has hum when off on the right channel only. Does anyone had similar issues ?
That prevents my mono amp to shut off.

CD transport coax > D90 > RCA > mono amps.
D90 used as preamp (XLR off).

I just received my D90 last evening and I also have hum from both channels when the unit is in standby. I will be tracing when I have some time.

This unit replaced an NAD M51, and I simply removed the NAD box and used the existing power cord and input and output cables previously connected to the NAD which exhibited no hum. I do believe the NAD has an output relay enabled in powered-on mode vs. standby. Perhaps this is the issue.

I haven't checked my A90 / D90 for this, but I have experienced this before with other equipment. The solution was to turn off the Class A Mono block manually. That was many years ago.

Kinda surprised the A90 / D90 is doing this, @JohnYang1997 is this expected behavior? How to fix?

 

[DavidBloch406]

I haven't checked my A90 for this, but I have experienced this before with other equipment. The solution was to turn off the Class A Mono block manually. That was many years ago.

Kinda surprised the A90 is doing this, @JohnYang1997 is this expected behavior? How to fix?

They’re saying D90, not the A90

 

[JohnYang1997]

I haven't checked my A90 for this, but I have experienced this before with other equipment. The solution was to turn off the Class A Mono block manually. That was many years ago.

Kinda surprised the A90 is doing this, @JohnYang1997 is this expected behavior? How to fix?

When it's standby the outputs are short to ground. (effectively the input of the down stream amplifier is shorted) So there shouldn't be any hum.

 

[JohnYang1997]

My D90 has hum when off on the right channel only. Does anyone had similar issues ?
That prevents my mono amp to shut off.

CD transport coax > D90 > RCA > mono amps.
D90 used as preamp (XLR off).

Was the rca cable close to power chords? Maybe swap left and right cables?