@solderdude As always thanks very much.
Will that toast any kind/type of earphones, iems, headphones etc2 irrespective of their specs/sensitivity etc2?
Got an e-mail message from Topping Sales manager, apparently they'll ship me the replacement over DHL. Sounds good..
It toasted dynamic over ears of mine, read about some IEM etc. I would follow toppings advice and request replacement unit regardless of headphones you use.
I thought it was esd and dc protection.
Water under the bridge now. Fingers crossed lessons learned all over.Sorry to hear it damaged/toasted a pair of your cans.
I bought mine after the review came out but never got around to using it. I was about to set it up when I came across the defects noted in this thread. I'm lucky that I didn't use it.
The ESD issue is the cause for blowing up the OPA opamp inside.
This would be annoying (and lead to complaints about the L30's failing) IF the DC protection had worked properly when this specific type of failure occurred.
It was the DC protection (not DC power supply or wallwart) failing to detect a huge DC on the amps output under these conditions.
The DC protection (I assume) works well when the output of the amp would only register DC.
However, the protection did not work in this specific failure mode. That part needed fixing aside from the ESD issue.
So the DC protection fix was implemented in 2012 version. Meaning even when ESD would have destroyed the OPA opamp inside the amp would simply not work anymore but headphones are protected. No more dead headphones.
Later the source of the ESD destroying the OPA opamp was confirmed by Topping (with higher than the norm test levels applied) and the fix for that was grounding the enclosure, and thereby also the potmeter shaft as that is screwed down onto the enclosure.
Let's put it this way... if the enclosure was grounded from day one ESD would never have been able to kill the OPA, no headphones would have been fried and the failure mode of the DC protection, in this particular failure mode, would never have been discovered.
The L30 is a very SAFE headphone amp from serial number 2012 and higher.
Is there a way to tell apart the 2012 model that has the ESD fix vs the 2012 model that does not?
The test would be to check if there is very little resistance between the RCA shield and metal enclosure screw on the back of the amp.
When that is connected you are 'safe' from ESD.
So easy to test but requires a multimeter.
Is there a way to automate this?
Is there a way to automate this?
Why? What do you fear would happen?If I had a pacemaker or ICD I wouldn't touch the Toppings.
I have no problem in waiting a month or two if they can confirm that a unit from the next batch will be sent (whatever serial number that will be).
Kind of interferences? Nothing good in any ways.Why? What do you fear would happen?