WolfX700 Measurement of Topping L30 Headphone Amp

[MSTARK]

Lets put it this way, I think even @JohnYang1997 has said if you only want single ended Topping amplifier, get this over the A90. So yes, you pay extra for features and aesthetics, as with every consumer product. The real question is what amps are available from other manufs. that provide the power and performance levels this does for comparable price. But the A90 has balanced inputs and outputs as preamp.

That explains a bit the price structure. One last question. In other designs (speaker amps especially) power supply plays a major role in a design and performance. How does it translate to these designs (including THX amps)?

edit
And would these designs benefit from beefier/linear PS?

 

[Veri]

That explains a bit the price structure. One last question. In other designs (speaker amps especially) power supply plays a major role in a design and performance. How does it translate to these designs (including THX amps)?

edit
And would these designs benefit from beefier/linear PS?

John already wrote in-depth about this before. The external switcher in L30 could result in lower noise than internal PSU in A90, simply because it is external. BUT if you use XLR in A90 you have a ground return path which makes it a non-issue. In any case I never had any noise problems in my A90 but it's not impossible in the worst case scenario.
If you mean if there is benefit to be had to use "better" power supply, answer is no, the power is never used without filtration etc, no well designed electronic design would do that. Edit: L30 power supply is 15VAC power anyway, not even AC it is very well designed!

 

[Jimbob54]

That explains a bit the price structure. One last question. In other designs (speaker amps especially) power supply plays a major role in a design and performance. How does it translate to these designs (including THX amps)?

edit
And would these designs benefit from beefier/linear PS?

See @Veri post above - the whole psu thing is odd- if the measurements dont show meaningful interference (they dont for the L30), why does it matter what PSU is used EDIT SUPPLIED, how could anything improve it?

 

[JohnYang1997]

See @Veri post above - the whole psu thing is odd- if the measurements dont show meaningful interference (they dont for the L30), why does it matter what PSU is used , how could anything improve it?

If I use Atom's power supply it will double(more than) the leakage (higher ps noise). Higher voltage will cause more heat. And very likely don't have the current output capacity of our stock ps even some have higher ratings. So for the people, DO NOT use any 3rd party supply for L30.

 

[Jimbob54]

If I use Atom's power supply it will double the leakage (higher ps noise). Higher voltage will cause more heat. And very likely don't have the current output capacity of our stock ps even some have higher ratings. So for the people, DO NOT use any 3rd party supply for L30.

Sorry- I didnt mean "use any PSU with it"- I meant why worry what the nature of the supplied PSU is- should have said supplied, not used. I will edit

 

[JohnYang1997]

Sorry- I didnt mean "use any PSU with it"- I meant why worry what the nature of the supplied PSU is- should have said supplied, not used. I will edit

Nah. I was simply borrowing the reply. It wasn't directing to your post but rather supplementary.

 

[Harmonie]

We can make it 1.5m for next batch. But I just want to know if it makes other people's life harder (because 1.2m chord has been used since like forever).

Good question, not (directly) related, but I didn't unpack the D90 stock cable, but use rather my own shielded one. Otherwise both 1,2m and 1,5m may be ok , but 1,5m would give more advantage while that 30 cm overlength shouldn't hurt other's deco.

 

[MSTARK]

I was under impression that LPS has lower high-frequency noise and faster transient response. Of cause, it all depends on implementation and cost.
I was just wondering if anyone have tried it and if so, were there any audible differences?

 

[JohnYang1997]

I was under impression that LPS has lower high-frequency noise and faster transient response. Of cause, it all depends on implementation and cost.
I was just wondering if anyone have tried it and if so, were there any audible differences?

All false and forget about it.

 

[MSTARK]

All false and forget about it.

Lol. Got ya.

 

[MSTARK]

@JohnYang1997
Is Topping working on new flagship designs. If so, how far can you take your “know how” and technology available?
A little off topic but I’m curios and perhaps something to look forward to.

 

[bahamot]

I was under impression that LPS has lower high-frequency noise and faster transient response. Of cause, it all depends on implementation and cost.
I was just wondering if anyone have tried it and if so, were there any audible differences?

Quote from Benchmark's blog:

LINEAR POWER SUPPLIES CAUSE HUM​

The noise problem is due to the fact that linear power supplies have large transformers and other magnetic components that operate at the AC line frequency (50 Hz to 60 Hz). These line frequencies are audible, and we are all too familiar with the hum and buzz that audio products can produce.​

 

[Veri]

All false and forget about it.

Preach.

If I use Atom's power supply it will double(more than) the leakage (higher ps noise). Higher voltage will cause more heat. And very likely don't have the current output capacity of our stock ps even some have higher ratings. So for the people, DO NOT use any 3rd party supply for L30.

So L30 VAC adapter is objectively superior to Atom's stock PSU, basically? I suppose that makes L30 even more of a bargain

Quote from Benchmark's blog:

LINEAR POWER SUPPLIES CAUSE HUM​

The noise problem is due to the fact that linear power supplies have large transformers and other magnetic components that operate at the AC line frequency (50 Hz to 60 Hz). These line frequencies are audible, and we are all too familiar with the hum and buzz that audio products can produce.​

Note that Benchmark means, audible hum coming from the device. Not in the signal, just a "room" hum. If a toroid transfo is near your desk, yeah you might hear it humming depending on how noisy your AC power line is, DC offset, ... ON THE OTHER HAND, some switchers make a very high frequency whine. Put your ear close to your home router for example, changes are you'll hear something. Just saying. Nothing is perfect
but some things get close~~

 

[3125b]

some switchers make a very high frequency whine.

True, always a concern in PC building, however that can be avoided, even very powerful switching power supplies can be dead quiet if designed for that purpose.

 

[Sak]

If I use Atom's power supply it will double(more than) the leakage (higher ps noise). Higher voltage will cause more heat.

By the way, on my sp200, when it is idle, it heats up quite a lot. And when I listen to music, there is almost no heating. If only for a long time, but still does not heat up to the same extent as in idle time.

 

[mshenay]

Doesn't SP200 use an internal low noise switching PSU, just like A90?

Sorry I meant a SPSU wall wort, I dig that it's got an IEC C14 connector for power input

 

[Veri]

I dig that it's got an IEC C14 connector for power input

Right. That's what I prefer too, those power bricks start to pile up lol I much prefer an AC cable

 

[MSTARK]

Quote from Benchmark's blog:

LINEAR POWER SUPPLIES CAUSE HUM​

The noise problem is due to the fact that linear power supplies have large transformers and other magnetic components that operate at the AC line frequency (50 Hz to 60 Hz). These line frequencies are audible, and we are all too familiar with the hum and buzz that audio products can produce.​

Sure, sure. But still, doesn’t switching power supply transmit noise back into power line. Therefor, affecting neighboring, sensitive component?

 

[MSTARK]

Would running something like L30 or D50 dac on battery power supply have any disadvantage?

 

[JohnYang1997]

Would running something like L30 or D50 dac on battery power supply have any disadvantage?

L30 can't be supplied by a battery. It's simply impossible. L30 is 15V AC in not DC.