• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Topping L50 Review (Headphone Amp)

wacomme

Senior Member
Joined
May 11, 2022
Messages
366
Likes
73
Have you happened to get one of these?
Also I'm looking for the same DAC+AMP combo, please share your experience so far
I like my SMSL DO100/Topping L50 combo. I've now had it for a little over two months. It fits my needs well. I use them mostly with my Sundara headphones and the L50 drives them well. If I had harder to drive headphones I might opt for the A30Pro, but I've heard that amp gets quite hot; the L50 is mildly warm. With a flip of a switch on the L50 I can switch from headphones to my desktop speakers (via L50's pass-through). I keep the volume on the L50 at max and adjust volume for both headphones and desktop speakers via the volume knob on the DO100 (or via the DO100 remote). The implementation works well.

My ONLY grip is that the DO100 has an auto-mute function which seems to have no purpose. Essentially, the dac shuts down if there's no signal from the left channel. This could be a problem for certain passages of music, though I haven't experienced this shutdown while playing music. Where it affects me is when calibrating my desktop speakers using REW. The dac shuts off (not power, but dac functionality) when calibrating just the right channel. I can get around this problem by turning the dac off and back on for each right channel measurement. But it's a PITA. However, despite this problem I'm keeping the DO100.
 

wacomme

Senior Member
Joined
May 11, 2022
Messages
366
Likes
73

Thank you for the feedback! Appreciate it
IMG_4148.jpeg
 

tiramisu

Member
Joined
Jun 24, 2022
Messages
94
Likes
92
That is impossible, a 4-pin to 2-pin adapter will lose half the voltage. There isn't enough pins on a standard 3.5mm adapter to give you the full output.
(Ebay/amazon sellers selling such a thing should be ashamed).
Doh! 3.5mm is TRS adaptable 3-pin but


Not being an electromagician it seems to me that the 4-pin XLR delivers 4 volts and the TRS delivers 2 volts

it shouldn't matter whether voltage is delivered balanced or down one pair of wires.
The voltage should remain the same.

volts x amps = watts
It may be my misunderstanding of I/V = R

Or are you saying the output voltage is the same on TRS as 4-Pin XLR (exact same circuit) and there is only one output voltage on this device?

Can you help fix my stupid?
 
Last edited:

RHO

Major Contributor
Joined
Nov 20, 2020
Messages
1,172
Likes
1,060
Location
Belgium
Doh! 3.5mm is TRS adaptable 3-pin but


Not being an electromagician it seems to me that the 4-pin XLR delivers 4 volts and the TRS delivers 2 volts

it shouldn't matter whether voltage is delivered balanced or down one pair of wires.
The voltage should remain the same.

volts x amps = watts
It may be my misunderstanding of I/V = R

Or are you saying the output voltage is the same on TRS as 4-Pin XLR (exact same circuit) and there is only one output voltage on this device?

Can you help fix my stupid?
I think you are mixing up input and output and are forgetting there is an amplifier in between.
 

Veri

Master Contributor
Joined
Feb 6, 2018
Messages
8,963
Likes
11,101
it shouldn't matter whether voltage is delivered balanced or down one pair of wires.
The voltage should remain the same.

volts x amps = watts
It may be my misunderstanding of I/V = R

Or are you saying the output voltage is the same on TRS as 4-Pin XLR (exact same circuit) and there is only one output voltage on this device?

Can you help fix my stupid?
Well it's simple XLR is + and -, 2V and 2V, for combined 4V(most common), with great common-mode rejection cancelling out noise. That is balanced. When you go XLR to RCA (or 3.5mm etc) you can only pick up the + or the - signal, 2V. It's not possible with a simple adapter. You just lack the connection path. Half is lost.
 

raif71

Major Contributor
Joined
Sep 7, 2019
Messages
1,936
Likes
1,926
1660089704823.png


Hi, I need to connect L50 to smsl m500 dac. Is the above 3pin xlr female to TRS 6.35mm cable appropriate? Thanks
 

seyeR Funnnnn

New Member
Joined
Jul 13, 2022
Messages
2
Likes
2
That's pretty much exactly what's been happening with mine, very annoying, manual says blinking LED means "unexpected output" guessing some kind of protection is being triggered, but why and by what I don't know.

So I emailed Topping Service about it and here's the reply I got back after sending in a video:

Hi,

Thank you for your video. In the video, L50 blinks four times and pauses for two seconds, indicating that L50 detects the direct flow and triggers the headphone protection.

We recommend that you set the L50 to medium gain or turn down the volume a bit.

Best Regards

--------------------

TOPPING SERVICE

Sounds legit, the only problem I have with my medium gain setting, to get it to a volume I like, I'm nearly at the end of my volume knob so I like high gain around 9-10 o'clock. However, I'm going to do some testing to see what happens now that I understand a little bit more.

I also asked them if they have a public facing document that explain the different blinking scenarios, we'll wait and see if they do but it's likely an internal only document they have.
 

Synrgy87

Member
Joined
Apr 7, 2021
Messages
20
Likes
13
So I emailed Topping Service about it and here's the reply I got back after sending in a video:



Sounds legit, the only problem I have with my medium gain setting, to get it to a volume I like, I'm nearly at the end of my volume knob so I like high gain around 9-10 o'clock. However, I'm going to do some testing to see what happens now that I understand a little bit more.

I also asked them if they have a public facing document that explain the different blinking scenarios, we'll wait and see if they do but it's likely an internal only document they have.

Hopefully they respond with something useful.

Have hooked mine back up to do a bit more testing, might look into some cooling mods, had a nosy inside, maybe some heatsinking or a vent / fan mod would help.

I'm guessing they mean current when they say it "detects the direct flow" may be a way to bypass this detection(likely not a good idea).
 
Last edited:

drake5000

Member
Joined
Feb 16, 2021
Messages
25
Likes
14
I have a question for Topping L50 owners. My unit has somewhat shaky/loosy volume knob. In other words, I need like 1-2° before starting to feel resistance and the volume would actually change. It almost feels like it dampened in some way. Before this I've had an Atom AMP and the knob there felt very crisp and sturdy.
Do you have similar issues with your L50 units?
Thanks in advance
 

Dunring

Senior Member
Forum Donor
Joined
Feb 7, 2021
Messages
342
Likes
397
I have a question for Topping L50 owners. My unit has somewhat shaky/loosy volume knob. In other words, I need like 1-2° before starting to feel resistance and the volume would actually change. It almost feels like it dampened in some way. Before this I've had an Atom AMP and the knob there felt very crisp and sturdy.
Do you have similar issues with your L50 units?
Thanks in advance
I just got one of these in and the volume wheel doesn't have any slack in it or delay. Next week I have another and can check on that too, but this one is crisp without any lag/delay in it. I really like the sound of this with a Topping D10b, they're a really good match. Also these 600ohm Beyerdynamic DT880's are no match for high gain mode, can't get past 50 percent volume before its too loud to be safe. Best part of these it doesn't raise the temp by 1-2 degrees in the room like the A30Pro did when it's left on. There's an SP200 next to it and it's not even as lightly warm as that can get. Going to try this on the Sennheiser HD800s next and see how it is.
 

djtetei

Active Member
Joined
Jul 5, 2022
Messages
137
Likes
62
Location
România
Best part of these it doesn't raise the temp by 1-2 degrees in the room like the A30Pro did when it's left on.
Keep in mind that Topping A30 Pro has a bigger power supply, able to provide more power and is located inside the unit, whereas the L50 has an external power supply.
 

hovation

Member
Joined
Mar 28, 2020
Messages
26
Likes
8
It sounds like you're saying that the gain is the same regardless if single-ended (RCA) or balanced (XLR/TRS) inputs are used. Not what I expected.
This is important to me as well since I'll be using a Topping E30 as the source with just 2Vrms input, wondering if we have official word or measurements of the output power at 300 ohm (if not more impedances as well perhaps) with unbalanced 2Vrms in. I was disappointed with the L30 (v1) and ended up returning it. I got a good deal on a refurbished Topping L50 but can (and will) return it for the L30 II ultimately if needed and if I'll have a decent amount of headroom for EQ.

I know that the output power is the same whether using the single-ended or balanced headphone out, but I imagine there will be less loudness or volume at the same position of the dial in the same gain setting when comparing 2Vrms and 4Vrms input. This is my concern. Since the E30 II gets its full rated (and measured, as per the ASR review) output with 2Vrms output, if the E50 takes a considerable hit in this department, that will definitely make a difference for my end setup. It would probably influence the decision of many others in a similar boat as well I imagine.
 

djtetei

Active Member
Joined
Jul 5, 2022
Messages
137
Likes
62
Location
România
@hovation
Let's do some mathematics:
The official specifications for L50 are 540 mW at 300 ohm.
This means that your source DAC or player has to deliver an output level of:
- 2.56 Vrms at High Gain setting
- 12 Vrms at Medium Gain setting
- 63 Vrms at Low Gain setting
Both Topping E30 and E50 have an output level of 2 Vrms on unbalanced outputs.
With 2 Vrms input level you can expect from L50 the following power figures:
- 327 mW at 300 ohm, on High Gain ain setting
- 13 mW at 300 ohm, on Medium Gain setting

What headphones you intend to drive with Topping L50?
 

drake5000

Member
Joined
Feb 16, 2021
Messages
25
Likes
14
@hovation
Let's do some mathematics:
Official specifications for L50 are 540 mW at 300 ohm.
This means that your source DAC or player has to deliver an output level of:
- 2.56 Vrms at High Gain setting
- 12 Vrms at Medium Gain setting
- 63 Vrms at Low Gain setting
Both Topping E30 and E50 have an output level of 2 Vrms on unbalanced outputs.
With 2 Vrms input level you can expect from L50 the following power figures:
- 327 mW at 300 ohm, on High Gain ain setting
- 13 mW at 300 ohm, on Medium Gain setting

What headphones you intend to drive with Topping L50?
By the way, regarding input sensitivity of Topping L50. The specsheet says: 2.7 Vrms for Hi Gain mode with BAL input, but the nominal BAL output for the DAC is 4 Vrms! Does it mean that I clip by default when using BAL OUT of the DAC with HI GAIN mode of L50?
 

staticV3

Major Contributor
Joined
Aug 29, 2019
Messages
2,639
Likes
3,726
Does it mean that I clip by default when using BAL OUT of the DAC with HI GAIN mode of L50?
No. You clip only if you turn the volume knob up enough.
Input sensitivity is the highest signal amplitude at the input before clipping with the volume set to max.
 

djtetei

Active Member
Joined
Jul 5, 2022
Messages
137
Likes
62
Location
România
By the way, regarding input sensitivity of Topping L50. The specsheet says: 2.7 Vrms for Hi Gain mode with BAL input, but the nominal BAL output for the DAC is 4 Vrms! Does it mean that I clip by default when using BAL OUT of the DAC with HI GAIN mode of L50?
If your DAC has a built-in preamplifier functionality, there is no reason to clip the input of the L50.
 

hovation

Member
Joined
Mar 28, 2020
Messages
26
Likes
8
@hovation
Let's do some mathematics:
The official specifications for L50 are 540 mW at 300 ohm.
This means that your source DAC or player has to deliver an output level of:
- 2.56 Vrms at High Gain setting
- 12 Vrms at Medium Gain setting
- 63 Vrms at Low Gain setting
Both Topping E30 and E50 have an output level of 2 Vrms on unbalanced outputs.
With 2 Vrms input level you can expect from L50 the following power figures:
- 327 mW at 300 ohm, on High Gain ain setting
- 13 mW at 300 ohm, on Medium Gain setting

What headphones you intend to drive with Topping L50?

Thanks for the detailed info! How did you do the math on that? Curious to find out.

Currently the HD6XX but looking into the 250Ohm DT1990 or something else soon as well.

It seems that the L30 II is able to deliver its full power with 2Vrms (I'm guessing at high gain) which might end up working out better for me since it will be quite a bit more than what the L50 can do. I don't want to have to upgrade the DAC if I can help it, the E30 is perfectly adequate for my needs, but the L30 II is only $20 (CAD) more than the L50 refurbished, just wondering if it's worth the savings. I suppose balanced could have future use as well, but not as concerned about balanced especially if it's required to get full performance out of the amp (which seems to be true).
 

djtetei

Active Member
Joined
Jul 5, 2022
Messages
137
Likes
62
Location
România
@hovation
You have nothing to lose by using balanced connections, but to gain.
Personally, I'm used to balanced connections and put them to good use.
Sennheiser HD 6xx are rated for 200 mW at 300 ohm, so with Topping L50 you can drive the headphones quite well (not ideal though), having about 2.13 dB of headroom (reserve power). That depends on how loud do you listen to your headphones.
Personally, I allow for up to 6 dB of headroom power reserve for any headphone amplifier I use, including the L50.
Keep in mind though that your headphones nominal impedance is 300 ohms and is possible to go higher up at certain frequencies, which means that the amplifier must be able to deliver a solid amount of power in order to drive the headphones with impunity.
 
Last edited:
Top Bottom