Topping L30 Headphone Amplifier Review

[deccatree]

The differences you hear are in gain... not power.

Connect the O2 to the E30, connect the O2 out to the L30 in and you can hear how loud the L30 really can go when it would have had a bit more gain.

Just tested your addition! In this config L30 really delivers! But nothing i'd do on a regular basis.
So, how much is max. gain of L30? maybe i overlooked it in the mass of data in this thread.

 

[half_dog]

The differences you hear are in gain... not power.

Connect the O2 to the E30, connect the O2 out to the L30 in and you can hear how loud the L30 really can go when it would have had a bit more gain.

I did it with two L30s... Unnecessary haha
I'm still impressed about the volume difference between those two (E30 and ODAC). I would suggest to open the Topping USB Audio Device Control Panel (such a lengthy name) got ot volume tab, Output and maximize it...

 

[solderdude]

Just tested your addition! In this config L30 really delivers! But nothing i'd do on a regular basis.
So, how much is max. gain of L30? maybe i overlooked it in the mass of data in this thread.

H = +9.5dB so 3x gain (2V -> 6V) cannot overload the amp
M = 0dB so 1x gain (2V -> 2V)
L = -9dB so 0.35x gain (2V -> 0.7V)

For 'standard' O2
H = +16dB = 6.5x (will overload the amp internally when connected to 2V source)
M = +8dB = 2.5x

 

[deccatree]

@solderdude Thank you very much for your tutoring!

 

[half_dog]

@JohnYang1997
I have a question, if it's not inconvenient...
If two L30 are fed with balanced signals from a E50 (eg.: positive to left channel and negative to the right channel for each L30, ground to ground), make a headphone cable with two TRS terminations (tip = positive, ring = negative and sleeve = not connected) for each amp/side - the potentiometers would at their maximum and volume would controled digitally on E50. With this configuration, the power output would be close to a A90 or this has other parts on its circuit which allows a higher output voltage? Is there any problem to leave the sleeve "pin" floating at the headphone output?
Best regards and happy new year a few days late

 

[solderdude]

Not John but there is no problem using it this way when you can make the needed conversion cables.

L30 one = L and -L . Connect L (tip) to pin 1 XLR-4 pin (L+) and R (ring) to pin 2 (L-)
L30 two = R and -R . Connect L (tip) to pin 3 XLR-4 pin (R+) and R (ring) to pin 4 (R-)
leave the ground open.

The balanced out for TRS (E50) is tip = +, ring = -, sleeve is ground.

potmeters at max or in same position (well above 9 o'clock) which you can now use as a balance control.

You can now draw 4x the power (double the voltage) and gain will have increased 2x (+6dB) for headphones above 32ohm.
12V = 4.5W in 32ohm (in high gain setting and volume maxed).
Could be needed for original HE6.

 

[MrBlitzpunk]

So... topping L30 is my first desktop amp, and im still learning about amps in general. This thing gets surprisingly hot after about less than 3 hours of use. is that normal? It's warm bordering to uncomfortable to touch, i would describe it as a bathtub filled with fresh hot water that's not hot enough to burn you/cause any pain but hot enough that you'd hesitate to jump in right away, or something like that.
I'd say it's about 45-50 degree celcius (judging by the very accurate and scientific measurements of my hand lol). It worries me that if it gets that hot on the outer casings, the innards must have it worse right? It's not to the point where im worried it'll explode, though if it does get that hot i would stop using it (maybe i am worried after all)

So should i be worried? Do they have some sort of measure to ensure the device longevity when it gets that hot that often? Because other than heat i haven't really experienced any issues at all after a month of use

Btw im using the newer 2101xx batch so (hopefully) explosion will be out of the question

 

[half_dog]

Not John but there is no problem using it this way when you can make the needed conversion cables.

L30 one = L and -L . Connect L (tip) to pin 1 XLR-4 pin (L+) and R (ring) to pin 2 (L-)
L30 two = R and -R . Connect L (tip) to pin 3 XLR-4 pin (R+) and R (ring) to pin 4 (R-)
leave the ground open.

The balanced out for TRS (E50) is tip = +, ring = -, sleeve is ground.

potmeters at max or in same position (well above 9 o'clock) which you can now use as a balance control.

You can now draw 4x the power (double the voltage) and gain will have increased 2x (+6dB) for headphones above 32ohm.
12V = 4.5W in 32ohm (in high gain setting and volume maxed).
Could be needed for original HE6.

"Like'ing" your reply is not enough to thank you as always @solderdude
Yes, I'm able to make the cables but where I live is quite hard to find a XLR - 4. So, it's not so beautiful but making a cable with two TRS's is "more" practical.

Holy cow, 4.5W! The A30 pro has been in my wish list, but with two L30 the A30 won't be necessary.
Really nice to know that's is doable
I have a almost finished cable for the Sennheiser HD6 - - family.l and I'm going to solder the TRS's on this and try this setup out.
Thanks again!

 

[artburda]

@JohnYang1997 Here in Switzerland someone is trying to sell a L30 with the SN 2010621087 without a power supply, which means the person already got an exchange unit. https://www.tutti.ch/de/vi/zuerich/...l30-kopfhoererverstaerker/49663103?redirected

 

[artburda]

@JohnYang1997 Here in Switzerland someone is trying to sell a L30 with the SN 2010621087 without a power supply, which means the person already got an exchange unit. https://www.tutti.ch/de/vi/zuerich/...l30-kopfhoererverstaerker/49663103?redirected

Looks like the seller deleted the offering after I kindly reminded him that it‘s not such a great idea.

 

[celloh]

Hello, is the l30 with the seria 2101+ and the e30 with the serial 2014+ safe?

 

[Veri]

Hello, is the l30 with the seria 2101+ and the e30 with the serial 2014+ safe?

Yes. The safe/fixed version = any 2012 version or higher. 2009 for example is the one you should not use to prevent any accident.

 

[catamphetamine]

Purchased a used L30 with a serial number 2011xxx
Found out about the issue.
It wasn't ebay so the item is non-returnable (it's a local Russian marketplace).
Scrolled through the pages of this thread.
I guess it's kinda fine if there're some speculations that it might "secretly" have the DC protection updated.
I've also soldered a wire to the ground pad of the PCB and then drilled a small hole in the backplate, through which the wire comes out of the device and onto the screw (I've soldered the wire circle around a bit so that it kinda reminds a squishy washer).
I guess it's fine.

 

[catamphetamine]

Oh, and by the way, there was a debate here that L vs M gain doesn't make a difference.
I've initially tested the device on M gain and concluded that the sound is pretty fun for the price.
Another day I switched to L because of the wider knob adjustment range, and heard that the stack sounds really boring.
It wasn't clear why, because I played the same track.
Only then I switched it to M gain and the sound became interesting again.
So M does sound better than L.
No, it's not the loudness factor.
The headphone is Focal Elegia, which is on sale for $375 on Adorama.

 

[solderdude]

So M does sound better than L.
No, it's not the loudness factor.

Well done on the grounding.

Do a blind test and compensate the input voltage when switching.
The only difference between L and M position is the attenuation of the input signal (and thus also the load resistance to the source).
The gain and circuit between L and M are exactly the same, no changes in the amp between L and M so whatever you are hearing can't come from the amp itself being different.

 

[catamphetamine]

The only difference between L and M position is the attenuation of the input signal (and thus also the load resistance to the source).

Yeah, I know it sounds non-realistic and I've read your views on this subject.
If I trust my ears, then my head starts moving into the rhythm on M gain and it's just "meh" on L gain.
Maybe the DAC sounds better (I did purchase a linear 5V wall-wart on aliexpress).
Maybe the potentiometer allows "ghostly" short spikes that provide the "headroom" for the bass to actually punch and be "pulpable" on a higher gain.
Maybe the headphones' "impedance swing" thing affects the sound, because they're "dynamic" ones, so the higher gain sounds better even when seemingly not used.

I've purchased the stack for one of my nephews, so I'm just evaluating it for a short time.
I have a Singxer sitting next to it, and I did have a feeling that the L30's sound on M gain is, funnily, somewhat similar to Singxer's (class A) in a way that my head starts moving. I use my head as a measuring device.

Well done on the grounding.

Thanks! Your comments have been very helpful. I simply scrolled down until I saw the penguin.
I wondered "why does this man even care answering the same question for the hundred's time?", being neutral and not being a Topping "groupie" or a Topping community manager.
Anyway, thanks and keep on soldering, dude.

 

[solderdude]

I wondered "why does this man even care answering the same question for the hundred's time?

Not everyone is willing to wade through 255 pages looking for info and for me, all L30 info is just in my head so easy to make a post and sometimes explain or elaborate a bit more.

Those were a lot of maybe's in the post. The most logical explanation is the level difference.

What you can should do is listen at M-gain with the player at -9dB and then halt the player, set to 0dB and amp to L. Listen again.

 

[Deleted member 23424]

Just in case anyone's currently looking on eBay for one of these. This clown is knowingly selling the dodgy headphone blowing early models. Have reported it as a product recall violation to eBay, but knowing eBay they'll do fuck all.

 

[half_dog]

Talking about grounding. Using the L30 paired with a S9 or a floating source (like a D10s feed by the S9) I can feel current flowing when I touch the L30 either S9 chassi (without its rubber case). I'd like to ask how can L30 be modified to be connected to earth ground. I was thinking about to implement this circuit:

https://www.diyaudio.com/community/attachments/cct-2-gif.612621/

The idea is to replace the barrel connector with some 3 path connector, move the transformer in to a case where a IEC C14 connector can be placed and implement the circuit above inside the amplifier...
But L30 uses a half wave rectifier and my knowledge on electronics is not enough to be sure if all this is a safe approach.
Any thoughts on this?

 

[solderdude]

Grounding is not needed for 2012 and later.
The enclosure normally gets its ground via the gear connected to it.

If you want ground just connect safety ground to the enclosure or the RCA shield using a piece of wire (which may introduce a groundloop)