WolfX700 Measurement of Topping L30 Headphone Amp

[JohnYang1997]

The imbalance between the left and right channels of D90 and L30 has a problem in selecting the volume POT.
The volume POT for volume control must use the taper A, but both use the taper B volume POT. This can be seen immediately by looking at the measurement graph. This is also the reason for the sudden change in volume with respect to the rotation angle.

Of course these are A taper....Who would make that mistake..

 

[TraverS]

Seriously, 9dB gain is just too low. With 9dB gain, the power reaches only around 2W@16R.
Otherwise, I need to find a preamp which destroys the value proposition of this amp.

 

[JohnYang1997]

Seriously, 9dB gain is just too low. With 9dB gain, the power reaches only around 2W@16R.
Otherwise, I need to find a preamp which destroys the value proposition of this amp.

Let me see you listening over 200mVrms. Just saying. If you set the gain too high people will complain that the volume of high gain jumps too much.

 

[Veri]

Let me see you listening over 200mVrms. Just saying. If you set the gain too high people will complain that the volume of high gain jumps too much.

I agree. If you want a super high gain amp just buy an SMSL SP200. For most user, this is an annoyance rather than benefit.

 

[3125b]

9dB equals 2.8x I think. Thats on the low side, but with the regular 2V in still gives you 5.6Vrms out. That should be plenty for regular headphones. 4x is common with other manufacturers. Otherwise a fourth setting would be needed, and at that price point ...

 

[zhaqenl]

I’m kind of confused by this:

Seriously, 9dB gain is just too low. With 9dB gain, the power reaches only around 2W@16R.
Otherwise, I need to find a preamp which destroys the value proposition of this amp.

Isn’t the graph showing 3.2W at 16R assumed to be the max level at the highest gain (being 9dB)?

 

[JohnYang1997]

Oh come on. Not again.

 

[TraverS]

I’m kind of confused by this:


Isn’t the graph showing 3.2W at 16R assumed to be the max level at the highest gain (being 9dB)?

Sorry, I forgot "with 2v source" which is a common output voltage of DAC.

Let me see you listening over 200mVrms. Just saying. If you set the gain too high people will complain that the volume of high gain jumps too much.

Well, I kinda wish I could use it to drive both a headphone and my 16R-93dB+ sensitivity full-range driver in a nearfield setup.

 

[JohnYang1997]

Sorry, I forgot "with 2v source" which is a common output voltage of DAC.



Well, I kinda wish I could use it to drive both a headphone and my 16R-93dB+ sensitivity full-range driver in a nearfield setup.

That's not what it's designed for. 93db sensitivity that's 93db/W not mw (around 60db/mw). So no. Not recommended.

 

[w1000i]

Topping should make a stepped attenuator edition of L30 and A90.

With WBT RCA input https://www.wbt.de/english/products/a/Kategorien/p/rca-sockets.html

 

[Toku]

No, it was already mentioned it will use an AC adapter. Just like JDS Atom.

What are the advantages of using 15V AC instead of DC? 　
I think that the disadvantages such as hum noise from the power source are greater by using AC15V.

 

[mt196]

What are the advantages of using 15V AC instead of DC? 　
I think that the disadvantages such as hum noise from the power source are greater by using AC15V.

I'm not an electronic engineer, but a lot of great products use 15V AC, like JDS Atom, Schiit products and also this L30, so maybe it is the other way around looking at their performances

 

[JohnYang1997]

What are the advantages of using 15V AC instead of DC? 　
I think that the disadvantages such as hum noise from the power source are greater by using AC15V.

No leakage current. Good isolation. Lowest mains noise single ended product on the market. Good compatibility with other unbalanced devices.

 

[TraverS]

That's not what it's designed for. 93db sensitivity that's 93db/W not mw (around 60db/mw). So no. Not recommended.

But wouldn't it be revolutionary if I can get better performance than Benchmark AHB2 at the low listening level with 10 times less price.

 

[JohnYang1997]

But wouldn't it be revolutionary if I can get better performance than Benchmark AHB2 at the low listening level with 10 times less price.

There will be something for that purpose. But not L30.

 

[renaudrenaud]

There will be something for that purpose. But not L30.

Which purpose? Performance or price

 

[WolfX-700]

Which purpose? Performance or price

I have seen some measurements-I am shocked and unbelievable about the measurement results.

I can’t say too much...but the measurement results I see are a triumphant victory for AHB2 at low listening levels...

In exaggerated words... that amplifier VS AHB2 is similar to AHB2 vs other amplifiers.


THD is lower than L30...

 

[Max DDD]

Hello everyone , new here , dear @JohnYang1997 , what is input impedance (2.5 k seems too low , maybe a typo) , dc coupled ?
are there trim pod to adjust volume pot unbalance ?
May we know power consumption , and delta T over ambient after , say , 30 min. ? (taken from below the unit with a thermocouple)

cant' wait to have one !!!

Own the E30 and is superior to a Canary dac/amp combo (very good indeed) ~8W gets hot (too hot)
Own audio gd nfb 5.2 very nice headphone amp/dac ...17W gets too hot for my liking
Dac tested through arcam's a19 headphone amp , (very clear and detailed , seems lacks "bass drive/autority" , maybe too dry?)

Thank U WolfX700 for Measurement !

 

[Racheski]

the orange ring around the volume knob, is that lit up or a painted color?

 

[Vini darko]

Well if the input impedance does present a issue with my cd player. I can use a soldering iron. Will just make a cable with some 8k resistors at the client end. Bob's your auntie issue fixed