Topping L30 II Review (Headphone Amp)

[solderdude]

No it won't work for the simple reason that the half-wave rectifier will make a positive and negative voltage. When you connect a DC voltage only the negative or positive voltage will be present. It needs both positive and negative to work.

 

[Lambo1985]

Not 'better' in any way, the L50 has just balanced in (TRS jack) alongside RCA in.

A feature the L50 has that may be interesting is that you can switch between balanced input and RCA input basically allowing you to use 2 different input sources.
The L30-II can also be used as a pre-amp (so RCA out through volume control)
The L50 can not do this and is only throughput (so input and output are only connected)


It does NOT have balanced headphone outputs though so there is not more power available. The XLR output is just for convenience (so you can use 6.3 TRS jack and XLR4 headphone cables on it.

You can buy a TRS to XLR4 converter and use that with L30-II with the exact same output power

For some reason, when my E50 is connected to the L30 II RCA SE and the L50 Balanced TRS, the L50 has a louder output on the 1/4 phone out in high gain compared to the L30 II in high gain (I don't have HP's with an XLR cable. Only 6.3 SE and 4.4 Balanced). So, it is louder using the Balanced connection in my direct comparison.

Also, in this exact set up, the E50/L50 Balanced is more dynamic (As in audile dynamic variance in the source audio), than E50/L30 II SE (The E50/L30 II SE sounds more compressed than E50/L50 Balanced). The E50/L50 TRS connection is audibly better. There is an obvious audible difference every time I try it out.

 

[solderdude]

The 'feeling of being more dynamic' is caused by the higher gain.
In fact... amps like this cannot possibly be 'more or less dynamic' as these amps both are equally linear in amplification. This is evident by the very low distortion.
Amps like this do not 'compress' at all so the dynamics cannot possibly be affected.
L30-II high gain = 16.5dB, L50 = 13.9dB so L30-II should have higher gain, L30 has much lower gain.
L50 has 4V out on balanced and 2V out on SE so there is 6dB level difference right there.

When comparing these amps you should lower the volume of the amp with the highest gain a little so that they have the same gain and then use digital volume control to adjust volume when you want to compare amps.
Or... use both in medium gain setting (L30-II 0dB gain and L50 -0.2dB gain) as the difference should be smaller.

Also there cannot possibly be any audible difference between RCA and balanced connections. The only real difference that can occur is that the balanced connection may have less 'unwanted' noise/hum when a ground loop exists.

It is quite logical you hear (perceive) all of this but that is not due to 'balanced' connections nor 1 amp being 'less dynamic' somehow but level differences.
When you would be talking about completely different designs (one being tube amp or having unusually high output R) then there might have been some merit in your observations. However, the L50 is the same circuit using the same components just balanced.

Perceived difference in dynamics is level determined, actual (electrical) dynamics is amplification linearity (not FR linearity) dependent and can be measured/shown.

 

[Miiksuli]

@solderdude Yup but the gain with the tube amps plays a different role.

 

[solderdude]

The non linearity of the gain with some tube amps can play a role and a higher output resistance (muddying the lows) and giving the impression that dynamics are less because relatively the mids are lower in level are the main reasons tube amps can be less dynamic.

They can be perceived as 'more dynamic' as when signal is compressed at higher levels the difference between soft and loud sounds is relatively smaller so you can hear softer sounds louder and believe one can thus hear more and think that the amp is more dynamic.

So yes, the mechanism is different but here too, when the tube amp has higher overall gain, distortion is low and output R is low the perceived difference (when so) will also be mainly gain related... or volume control taper dependent even.

 

[Lambo1985]

The 'feeling of being more dynamic' is caused by the higher gain.
In fact... amps like this cannot possibly be 'more or less dynamic' as these amps both are equally linear in amplification. This is evident by the very low distortion.
Amps like this do not 'compress' at all so the dynamics cannot possibly be affected.
L30-II high gain = 16.5dB, L50 = 13.9dB so L30-II should have higher gain, L30 has much lower gain.
L50 has 4V out on balanced and 2V out on SE so there is 6dB level difference right there.

When comparing these amps you should lower the volume of the amp with the highest gain a little so that they have the same gain and then use digital volume control to adjust volume when you want to compare amps.
Or... use both in medium gain setting (L30-II 0dB gain and L50 -0.2dB gain) as the difference should be smaller.

Also there cannot possibly be any audible difference between RCA and balanced connections. The only real difference that can occur is that the balanced connection may have less 'unwanted' noise/hum when a ground loop exists.

It is quite logical you hear (perceive) all of this but that is not due to 'balanced' connections nor 1 amp being 'less dynamic' somehow but level differences.
When you would be talking about completely different designs (one being tube amp or having unusually high output R) then there might have been some merit in your observations. However, the L50 is the same circuit using the same components just balanced.

Perceived difference in dynamics is level determined, actual (electrical) dynamics is amplification linearity (not FR linearity) dependent and can be measured/shown.

Do you have the 3 units in front of you to compare? - I do. - I guarantee that anyone with a trained ear would be able to notice the difference.

What you are stating is akin to looking at a waveform and being able to tell if it's a Metallica song or an ABBA song. Even if I were to record the output of both amps, volume match, and post the waveforms of the same audio, you would not be able to tell any difference in slight program material dynamics. You'd just see amplitude & peaks. Any dynamic variance would be lost somewhere in the body of that waveform.

I'm just hoping that my personal experience helps someone make an informed decision.

 

[half_dog]

You'd just see amplitude & peaks.

A combination of peaks and valleys (crest and throughs if you prefer) are what "form" dynamic, no?
I do believe you are hearing something different but I think it might be related to, probably a defective unit or an external factor. Maybe something around L30 II can be disturbing its signal, ground leakage, EMI...

 

[Lambo1985]

A combination of peaks and valleys (crest and throughs if you prefer) are what "form" dynamic, no?

Yes, it is. However, the top of the peaks are usually transient attacks short in duration. The amplitude is a sum of complex multi element program material. - You can look at a waveform that looks flattened (brickwalled to death), completly filled in amplitude, and still percieve a certain amount of dynamic variance based on the program material. It could sound super compressed OR very dynamic. - What I'm saying, is that it's virtually impossible to tell these particular things by graphs and measurements.

 

[solderdude]

I guarantee that anyone with a trained ear would be able to notice the difference.

uh huh...

Even if I were to record the output of both amps, volume match, and post the waveforms of the same audio, you would not be able to tell any difference in slight program material dynamics.

Absolutely true that would be impossible to tell by looking at the waveforms in an audio editor or scope shot by eye... but.... statistics of the song and nulling can show this.

IF you were able to record (192/24 with at least 3dB headroom) the output of both amps (under actual load would be ideal) and you would post (or null) the recordings then the recorded differences should be audible.
You could even null/compare to the recording of the same song before it goes to the amp (directly from DAC out) and even see (sorry listen) which amp colors the sound and reduces the dynamics.

 

[oleg87]

Even if I were to record the output of both amps, volume match, and post the waveforms of the same audio, you would not be able to tell any difference in slight program material dynamics.

What? Where would they go? The wiggling voltage (and the corresponding current) coming out of your amp is what makes the driver move and make sound. Measuring it tells you everything there is to know about dynamics as far as your amp is concerned.

 

[Lambo1985]

What? Where would they go? The wiggling voltage (and the corresponding current) coming out of your amp is what makes the driver move and make sound. Measuring it tells you everything there is to know about dynamics as far as your amp is concerned.

I mean recording the output of the phone outs into an audio interface, onto a DAW on PC/MAC.

 

[Lambo1985]

uh huh...


Absolutely true that would be impossible to tell by looking at the waveforms in an audio editor or scope shot by eye... but.... statistics of the song and nulling can show this.

IF you were able to record (192/24 with at least 3dB headroom) the output of both amps (under actual load would be ideal) and you would post (or null) the recordings then the recorded differences should be audible.
You could even null/compare to the recording of the same song before it goes to the amp (directly from DAC out) and even see (sorry listen) which amp colors the sound and reduces the dynamics.

It'll be a pain to do (since i have everything physically set up the way i like) but I'm going to try a null test.

 

[solderdude]

Yep, it'll not be so easy. Especially when considering the load and the balanced vs SE outputs.
Perhaps compare SE outs only first.
Use Deltawave or post excerpts somewhere to be downloadable. 30 seconds should be enough.

 

[Lorenzo]

I bought the Topping L30 II, for use as a preamp and therefore to be able to benefit from a power gain.
I have a John Linsley-Hood 1969 Class A Amplifier aka Nobsound NS-02g of only 2x15 Watts, but a pair of Magnat Quantum 757
with an efficiency of 93 dB. Also SMSL SU-8 V2 as DAC.
To obtain more power I added the preamp-buffer
FX Audio TUBE-01 6J1.
Quite satisfied with the result, and then I read amirm's analysis about the gain that could be obtained and it really interested me.
The result is absolutely extraordinary ! The gain is set to the middle position (0 dB) and this is more than enough for comfortable listening.
Apart from the gain, it's an amazing quality of SOUND! clarity, depth of the sound stage over the entire sound spectrum.
I specify that I use Foobar with Flac, Hi-Res, and DSD formats.
In summary a fantastic upgrade of the whole system !
Thanks again ASR !

 

[Rja4000]

I'm trying to match the 50mV result, but I can't replicate it.

Best I get so far is 98.4dB SNR @50mV

Not too bad, though

RME ADI-2/4 Pro SE 2V output > Topping L30 II HPA Mid gain, volume reduced to 50mV output
E1DA Cosmos Load board (a MUST HAVE for amateur headphones amp measurement) set for 300 ohm unbalanced
RME ADI-2/4 Pro SE RIAA +20dB M/S mode (RIAA reverse curve applied in software).
Software Virtins Multi Instrument 3.9.8.0

The other channel is 0.1dB lower.

 

[staticV3]

Best I get so far is 98.4dB SNR @50mV

The APx555B requires help from an external LNA to measure 50mV SNR of >98dB (see here), so it's fair to assume that you're at a similar point with your RME.

 

[AndreaT]

Hi,

Is anyone using L30 II with E50? Just ordered an E50, but cannot decide if I should go for L50 or L30II? I don't really need a balanced interface which L50 has, and L30 II has a preamp function that I may combine with my existing setup when switching between headphones and the speakers.

A great combination. I use it as the bedside combo (with Topping M50 as a source) for my late night listening sessions w IEM. Flawless performance and functionality

 

[ROTUND_Catto]

is it safe to change the power brick of the L30 ii amp to a toroidal transformer ? Mine has 12V and 18V outputs.

 

[Rja4000]

is it safe to change the power brick of the L30 ii amp to a toroidal transformer ? Mine has 12V and 18V outputs.

What do you expect as a gain ?

 

[threni]

What do you expect as a gain ?

+/-3v, it would appear...