Topping L30 Headphone Amplifier Review

[solderdude]

What will be their protection against voltages on 2102 batches?

The 2102 batch will probably have a PCB with an easier provision to connect the enclosure to audio ground.
In the 2012 this is something that is retrofitted (by hand I assume).
Otherwise I would not expect any changes from the 2012 batch which is fixed in both ESD protection and DC protection.

Just assumptions (conjecture) on my part. Only @JohnYang1997 will know for sure. It's just what I would do in this case.

 

[C0B-1D3-9]

The 2102 batch will probably have a PCB with an easier provision to connect the enclosure to audio ground.
In the 2012 this is something that is retrofitted (by hand I assume).
Otherwise I would not expect any changes from the 2012 batch which is fixed in both ESD protection and DC protection.

Just assumptions (conjecture) on my part. Only @JohnYang1997 will know for sure. It's just what I would do in this case.

Got it, thank you!

 

[zenki]

Oh my... ESD issues.
How to check?
Basically if you have ESD and touch L30 then it's toast/headphone toast?
Upon further reading there's also a DC issue? What's this one?
Any other issues missing out?

 

[solderdude]

Oh my... ESD issues.
How to check?

You can check (2012 version) by testing continuity (resistance) between the rear screw on the back plate and the RCA shield.
When there is conductance (low resistance) it is O.K.. When you measure open circuit (OL in display) best to remove the back plate and make a connection between the RCA shield and the screw on the rear. This should be sufficient.

AFAIK the 2012 ones will have the ESD protection.
The ones above 2012 will all be properly grounded.
The 2011 batch does not have ESD protection (grounding of enclosure) but does have improved DC protection (also AFAIK) and would recommend to get a replacement.
The ones below 2010 do not have proper DC protection nor ESD protection. These should be replaced.

 

[zenki]

@solderdude Don't have gadgets for testing.
And that REPLY/INFO should be stickied for others to check/found out.

Also,
Basically if you have ESD and touch L30 then it's toast/headphone toast?
Upon further reading there's also a DC issue? What's this one?
Any other issues missing out?
TIA

 

[solderdude]

@solderdude Don't have gadgets for testing.
And that REPLY/INFO should be stickied for others to check/found out.

Also,
Basically if you have ESD and touch L30 then it's toast/headphone toast?
Upon further reading there's also a DC issue? What's this one?
Any other issues missing out?
TIA

Touching the L30 (serial numbers below 2010) does not mean it is toast.
When you touch it while it is connected to ground via a DAC (E30 mostly as a stack) that is connected to a PC via USB then, and when your body has been charged with over 10kV static charge.

You will know when this happens to you when you will 'feel' a jolt, (or even hear or see a small spark) when touching something that is grounded, right after you got up from a cloth covered couch wearing slippers or on carpet in very dry conditions.
Lower voltage static discharges usually are not a problem.
Static charge usually slowly 'dissipates' on the human body as that is conductive. The speed of this depends on how you make contact with the floor.
Bare feet will discharge faster than rubber slippers or dry socks.

The DC protection not functioning properly came into focus when more than 1 L30's went dead (I assume by static discharge) and it turned out under these conditions the DC protection (which does work under normal circumstances) failed and could blow up connected headphones.

 

[zenki]

So the the thing that kills headhones is the DC protection failure? and ESD cause that condition to happen?

 

[solderdude]

So the the thing that kills headhones is the DC protection failure? and ESD cause that condition to happen?

correct. It is the DC protection that fails when a specific component fails in the amp itself.
This component can fail when a considerable ESD pulse is applied to the enclosure.

 

[zenki]

@solderdude As always thanks very much.
Will that toast any kind/type of earphones, iems, headphones etc2 irrespective of their specs/sensitivity etc2?

 

[solderdude]

I can't help with that

 

[facboy]

i was reassured by the communication from @JohnYang1997 about the ESD fix being retrofitted to all 2012+, so registered with my retailer for replacement today . thx also to @solderdude for his explanations.

 

[ShiZo]

I can't help with that

So 2012 doesnt have all.the fixes (esd fix but not grounding)? The ones after will have both?

 

[JohnYang1997]

If you haven't got the replacement arranged yet, you'll basically have an all fixed unit.

 

[Yoyop]

If you haven't got the replacement arranged yet, you'll basically have an all fixed unit.

Great, I've got the Topping mail Yesterday (01/22) for sending me the new unit (maybe 2101 S/N lol), they needed my phone number and address
They'll send me next week I guess, and said it'll be DHL delivery.

So i'll have all fixes great job Topping and @JohnYang1997

 

[solderdude]

So 2012 doesnt have all.the fixes (esd fix but not grounding)? The ones after will have both?

ESD fix = grounding.

 

[ShiZo]

ESD fix = grounding.

I thought it was esd and dc protection.

 

[filipduarte]

If you haven't got the replacement arranged yet, you'll basically have an all fixed unit.

Thank you John for your response and patience with us. Is there any estimate of when these new units will be ready?

 

[mwong0412]

Hi @JohnYang1997 , just wondering if I order the L30 through Taobao (I live in HK), would I get the version with the ESD fix or just the 2012 without the ESD fix? Really wanna get it but would rather wait until the ESD fix has been applied.

 

[JohnYang1997]

Hi @JohnYang1997 , just wondering if I order the L30 through Taobao (I live in HK), would I get the version with the ESD fix or just the 2012 without the ESD fix? Really wanna get it but would rather wait until the ESD fix has been applied.

All new purchases should be fixed.

 

[mwong0412]

2

All new purchases should be fixed.

sweet! gonna be my first amp, gonna get the e30 as well! thanks for being so responsive man.