Topping L30 Headphone Amplifier Review

[Overseas]

FYI some people are making false and diffamatory claims about ASR members (us) and Amir on other sites This one was on a short discussion about the L30 : https://www.head-fi.org/threads/aud...ns-and-discussion-thread.749762/post-16150610
It's not the first one that I see, unfortunately.

View attachment 110089

Well, I am an economist converted to audiophil-ism, I don't know heck about technical stuff, I just enjoy good music played by good equipment.
But:
- Amir publishes his measurements - any detractor is free to publish his measurements in case Amir's are biased
- a whole bunch of other technical guys endorse L30 performance
- my importer also confirms a new shipment of L30 is on the way with both problems fixed

 

[solderdude]

Looks like some others are trying to sort this out right now. Here's a quick how-to:

Step 1: Remove the volume knob - use a non-marring tool to work it off the post. Then use small pliers to unscrew the nut, it's not tight.

View attachment 110555

Step 2: Remove these two screws from the rear. They're 2mm hex. No need to remove the screws above the RCA's.
View attachment 110556

Step 3: Slide out the PCB and look in the front left corner for IDs.
View attachment 110557

While it is a good thing to add ground in older serial numbers IF you don't want to have it replaced it is a good thing to know that even when you grounded the chassis, and lower the chance of ESD destroying the amp there still is the not functioning DC protection.
To fix this firmware AND hardware modifications are needed.

The only reason to open am L30 up is to check if the enclosure is grounded.
For those with a multimeter this is easy. For those that don't own one (they cost like $10.-) and want to check just to be sure IF your 2012 revision has been grounded is to only remove the backplate (4 screws) and see if there is a wire or contact between the enclosure and PCB.
That's why I asked if someone is willing to post a picture of the amp with only the rear plate removed.

 

[GGroch]

That's why I asked if someone is willing to post a picture of the amp with only the rear plate removed.

Please find attached my just received replacement L30 serial 2012 (next digit 6). I see no grounding wire.

With the back plate on, when tested with a multi-meter there is no continuity between either of the 2 rear chassis screws and the -(Ground) conductor on the R/L inputs or outputs. However, there is continuity between the 2 rear chassis screws and the 2 rear RCA Input and Output screws (white sockets with screws removed in photo). I checked my defaced but functional L30 Serial 2007 and there is no continuity with the RCA screws on that one.

It is certainly possible that this difference is random chance due to differences in back panel paint.

 

[companyja]

Please find attached my just received replacement L30 serial 2012 (next digit 6). I see no grounding wire.

With the back plate on, when tested with a multi-meter there is no continuity between either of the 2 rear chassis screws and the -(Ground) conductor on the R/L inputs or outputs. However, there is continuity between the 2 rear chassis screws and the 2 rear RCA Input and Output screws (white sockets with screws removed in photo). I checked my defaced but functional L30 Serial 2007 and there is no continuity with the RCA screws on that one.

It is certainly possible that this difference is random chance due to differences in back panel paint.

Interesting. Does this mean that your 2012 model is ESD protected or is the continuity between the ground connector and chassis screws essential?

 

[ngs428]

Please find attached my just received replacement L30 serial 2012 (next digit 6). I see no grounding wire.
View attachment 110599

With the back plate on, when tested with a multi-meter there is no continuity between either of the 2 rear chassis screws and the -(Ground) conductor on the R/L inputs or outputs. However, there is continuity between the 2 rear chassis screws and the 2 rear RCA Input and Output screws (white sockets with screws removed in photo). I checked my defaced but functional L30 Serial 2007 and there is no continuity with the RCA screws on that one.

It is certainly possible that this difference is random chance due to differences in back panel paint.

My 2009 has continuity (0.2 ohm) between the left chassis screw and the output screw and then between the right chassis screw and the output screw. Same continuity between the 2 chassis screws.

 

[catalogguy]

I just today received my replacement coordinated through Apos and delivered by USPS. It does not rattle (I’ll have to get back to you on whether it hums!)

 

[usern]

Please find attached my just received replacement L30 serial 2012 (next digit 6). I see no grounding wire.
View attachment 110599

With the back plate on, when tested with a multi-meter there is no continuity between either of the 2 rear chassis screws and the -(Ground) conductor on the R/L inputs or outputs. However, there is continuity between the 2 rear chassis screws and the 2 rear RCA Input and Output screws (white sockets with screws removed in photo). I checked my defaced but functional L30 Serial 2007 and there is no continuity with the RCA screws on that one.

It is certainly possible that this difference is random chance due to differences in back panel paint.

There is no grounding this device that gets power from an adapter. It doesn't have wiring to ground, earth. Devices with IEC plug with 3 conductors might be grounded if the house electrical outlets are grounded.

 

[GGroch]

There is no grounding this device that gets power from an adapter. It doesn't have wiring to ground, earth....

The ground I refer to is not AC Power ground, it is the audio ground (outer RCA ring, as opposed to the signal, center pin) found in all unbalanced audio connections. I understood from previous poster comments that the newest full protection fixed units would have an additional wire connecting the audio ground to the chassis. I do not see that from the rear of my 2012 replaced L30. There is no continuity between these outer rings and the rear chassis screws of my replaced L30.

 

[companyja]

I gave in an ordered a Topping E30+L30 combo on Ali, the seller was great and assured me they sell the newest revision but I'm thinking chances are they don't know whether the 2012 units they have are randomly ESD protected or not. With any luck I might get a 2101 unit, haven't seen those yet.

Just randomly thought about just how much money Topping is losing because of a single grounding wire, all those units they have to replace for free...sad to see Topping having these mishaps recently, with the E30 polarity and the L30 protection, since they produce really well-built products in general.

 

[solderdude]

Please find attached my just received replacement L30 serial 2012 (next digit 6). I see no grounding wire.
View attachment 110599

With the back plate on, when tested with a multi-meter there is no continuity between either of the 2 rear chassis screws and the -(Ground) conductor on the R/L inputs or outputs. However, there is continuity between the 2 rear chassis screws and the 2 rear RCA Input and Output screws (white sockets with screws removed in photo). I checked my defaced but functional L30 Serial 2007 and there is no continuity with the RCA screws on that one.

It is certainly possible that this difference is random chance due to differences in back panel paint.

Hmmmm... certainly looks like a '10% chance' version. If I were you I would put a wire between the groundplane and the chassis screw. I wonder how Topping made the connection... I was hoping for a picture clearly showing this.
When there is no continuity between the RCA shield and the enclosure (measure the bare screw thread of the enclosure) then it is not ESD fixed yet.
Anodized aluminium is not conductive.

 

[carlcamper]

My unit arrived in the Philippines this morning, serial 2012, so far so great!

 

[JensH]

Hmmmm... certainly looks like a '10% chance' version. If I were you I would put a wire between the groundplane and the chassis screw. I wonder how Topping made the connection... I was hoping for a picture clearly showing this.
When there is no continuity between the RCA shield and the enclosure (measure the bare screw thread of the enclosure) then it is not ESD fixed yet.
Anodized aluminium is not conductive.

I received my L30 replacement (2012) a couple of days ago. I measured around 13 ohm from the screws to the RCA connector.
I then opened the unit and took a picture of the ground connection, see below. It seems like they use a pogo pin soldered to the PCB and some conductive (silver paste?) paint on the backplate. Some engraving under the printed area was visible. This probably ensures that the paint will get in contact with the metal and not just the anodized (isolating) surface.

To be 100% sure that the shaft of the potentiometer is grounded, I added a wire as shown on the picture below. It also connects the housing of the two switches to the ground plane. The wire is soldered to the ground pin of the jack connector.

The DC detection circuit has also been changed compared to the old version.

 

[threni]

So I just got my replacement, S/N 2012 arrived in 3 days with dhl, no taxes, awesome but now that I'm about to set it up I heard some rattle that apparently comes from my E30, does any yours do it? can I just open it and see if something is loose?

I just today received my replacement coordinated through Apos and delivered by USPS. It does not rattle (I’ll have to get back to you on whether it hums!)View attachment 110631

It was the E30 which apparently rattles, not the L30. (My E30 doesn't rattle).

 

[JohnYang1997]

I received my L30 replacement (2012) a couple of days ago. I measured around 13 ohm from the screws to the RCA connector.
I then opened the unit and took a picture of the ground connection, see below. It seems like they use a pogo pin soldered to the PCB and some conductive (silver paste?) paint on the backplate. Some engraving under the printed area was visible. This probably ensures that the paint will get in contact with the metal and not just the anodized (isolating) surface.

View attachment 110709

To be 100% sure that the shaft of the potentiometer is grounded, I added a wire as shown on the picture below. It also connects the housing of the two switches to the ground plane. The wire is soldered to the ground pin of the jack connector.

View attachment 110710

The DC detection circuit has also been changed compared to the old version.

I don't like the mod in the end. Would probably affect performance.
And yeah a fixed device should look like this.

 

[JohnYang1997]

Guys don't remove the volume knob. The process will act as an external force on the pot that it will be loose somewhat causing the "give" some people mentioned previously. So if you want to check if you have the esd fixed just remove the back plate and you should see the contact pin.

 

[threni]

View attachment 110710

The DC detection circuit has also been changed compared to the old version.

That wire looks problematically close to the other contact on the right-most switch!

I do not deserve typing privileges on this site.

 

[carlcamper]

Luckily I seem to have the ESD fix as well, thanks @SHENZHENAUDIO !

 

[nxnje]

https://www.audiosciencereview.com/...-headphone-amplifier-review.15226/post-652068
When threads get this long we could do with an FAQ to point to some of the important posts. Can the first reply be reserved for later editing just in case or something?

thanks for your kind reply, I didn't see that post as this has become very long and it's not easy to read everything, it takes so much time.
I will save this particular message.

 

[nxnje]

I don't like the mod in the end. Would probably affect performance.
And yeah a fixed device should look like this.

How do you think this will affect performance? I'm not a geek in this sense so it's just curiosity.

 

[solderdude]

How do you think this will affect performance? I'm not a geek in this sense so it's just curiosity.

performance is not changed.