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Topping L30 Headphone Amplifier Review

Shadez

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Why does the L30 require such a high input voltage from the DAC to achieve its quoted output power, it only has a single ended input so typically will only receive 2v where think it needs 3.7v? I have the E30 as the DAC to my Zen Can and that hits maximum output power both SE and Balanced with just 2v input from the DAC as do most balanced amps I belive.
 

Jimbob54

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Why does the L30 require such a high input voltage from the DAC to achieve its quoted output power, it only has a single ended input so typically will only receive 2v where think it needs 3.7v? I have the E30 as the DAC to my Zen Can and that hits maximum output power both SE and Balanced with just 2v input from the DAC as do most balanced amps I belive.

Asked and answered many times in this very thread. Use advanced search to look only in this thread.

TLDR- because thats what it was designed to do. For the potential customer, the better question is, do you need more than what it can output with a 2v DAC and is it clear what that maximum is?
 
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half_dog

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Why does the L30 require such a high input voltage from the DAC to achieve its quoted output power, it only has a single ended input so typically will only receive 2v where think it needs 3.7v? I have the E30 as the DAC to my Zen Can and that hits maximum output power both SE and Balanced with just 2v input from the DAC as do most balanced amps I belive.
I can't tell better than the designer. L30 is gain limited this way the amp won't clip under heavy load (32ohm and below)...
 

Shadez

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what is the relevance of not clipping under 32ohm sorry I don't understand the connection, so the gain on the l30 is dependant of the voltage input of the signal not the power supplied to the opp amps then?
 

half_dog

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what is the relevance of not clipping under 32ohm sorry I don't understand the connection, so the gain on the l30 is dependant of the voltage input of the signal not the power supplied to the opp amps then?
No, no... The gain is determinated by its internal circuit. Gain values have no relation to input voltage. However power output is related to the power supply, output circuit components and load. Buut for the amp reaches its highest power out the output circuit should be feed with a voltage value that allows it driven a specific load without saturating (clipping). Example: JDSLABS Atom has a higher gain than L30 and a similar voltage power supply output (+-15V), this higher gain makes it reachs 270mW over 300 ohm and 1.1W over 32 ohm - clipping. L30 being feed with 2V reaches only 110mW on 300ohm but 1W over 32ohm without clipping. This is possible because L30 has a higher capability to drive heavy loads than Atom. If you feed more voltage to L30 it will provide more power but Atom won't... Look at Atom+ and a10h (it has almost the same output circuit from L30) reviews, mainly the THD vs voltage output. A10h has a much better behavior...
Sorry any grammar mistake, I'm not native English speaker x.x
 
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Seems like new topping L50 have both balanced and se inputs. Does it means that the balanced inputs electrically not connected, i.e i can use my 9038s dongle balanced output without killing it?
 

Veri

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Seems like new topping L50 have both balanced and se inputs. Does it means that the balanced inputs electrically not connected, i.e i can use my 9038s dongle balanced output without killing it?
I don't understand why the one thing would lead to the other. Pretty sure that, no, 9038s should not be connected to any amp (unless you provide it ground potential with some sort of DIY-way of cabling). Only 9038d can be connected to anything no problem.
 
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. Pretty sure that, no, 9038s should not be connected to any amp (unless you provide it ground potential with some sort of DIY-way of cabling

but, balanced connection without ground like common thing? i heard it often used to eliminate ground loops, for example
 

Veri

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but, balanced connection without ground like common thing? i heard it often used to eliminate ground loops, for example
It's because it is a 2.5mm connection meant to be connected to headphones. Not meant for line-out. 4.4mm pentaconn for example could support a proper grounding pathway if I'm not mistaken. But 2.5mm cannot, it just has positive and negative signal effectively doubling power, but that's it.
 

Shadez

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No, no... The gain is determinated by its internal circuit. Gain values have no relation to input voltage. However power output is related to the power supply, output circuit components and load. Buut for the amp reaches its highest power out the output circuit should be feed with a voltage value that allows it driven a specific load without saturating (clipping). Example: JDSLABS Atom has a higher gain than L30 and a similar voltage power supply output (+-15V), this higher gain makes it reachs 270mW over 300 ohm and 1.1W over 32 ohm - clipping. L30 being feed with 2V reaches only 110mW on 300ohm but 1W over 32ohm without clipping. This is possible because L30 has a higher capability to drive heavy loads than Atom. If you feed more voltage to L30 it will provide more power but Atom won't... Look at Atom+ and a10h (it has almost the same output circuit from L30) reviews, mainly the THD vs voltage output. A10h has a much better behavior...
Sorry any grammar mistake, I'm not native English speaker x.x[/Q
 

Shadez

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thanks, so as an example my ifi Zen Can can run quite happily at full power with 2v in, so is this just a different design as many Amps mid and upwards do not rely on the DAC input power to reach their full potential.
 

Spiral_Architect

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Recently purchased the L30 to pair with my E30 for a compact high-quality stack. The S/N I got is 2101; i've skimmed through the thread and found various information on two successive revisions that the unit underwent, to related to DC protection circuit and sensitivity to ESD. I gather that all units with 2012+ S/N should be in one way or the other fixed at the factory and considered 100% safe ?

Regarding the ESD fix, is it related to proper grounding of the chassis ? With a meter It seems that the chassis (using one of the metal screws) is connected to the signal ground.

Gave it a listen with HD650 and it sounds perfect to me, as the objective measurements suggest. It replaces my extremely bulky dual-chassis AMB M3 that I built a few years ago. That should be a high-performance amp as well (don't have the opportunity to perform any reliable measurement on it) but the amount of space and weight it takes up is something like 30 times the little L30. With heat and power consumption that matches its size, thanks to the overkill class A mosfet output stage. From a purely subjective standpoint it's hard to tell any difference between the two (it's very hard to A/B amps). Probably both are almost transparent and quite close to a piece of wire with gain for the HD650 that has no particularly special power requirements. Given the stellar measurements, the L30 should be much closer to perfection...
 

half_dog

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thanks, so as an example my ifi Zen Can can run quite happily at full power with 2v in, so is this just a different design as many Amps mid and upwards do not rely on the DAC input power to reach their full potential.
Actually it relies on the input signal but 2V(even a little less) is enough to it reaches its maximum power output - considering the saturation point. That's about gain...
 

Jave

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@JohnYang1997 - I recently received my L30 replacement and the volume pot has a little give. I can move it from side to side without changing the volume, like it doesn't sit well. How can I fix it?
 
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