Many of my readers will know about the issues with early generation Topping L30 amplifiers. Unfortunately, they had a problem with static discharge shorting the unit and potentially destroying headphones. Topping, being the stand-up company that it is, sent out replacement units for those with the problem free of charge. They identified the problem as those units starting with 2011 or lower serial numbers. Hats off to Topping (pun intended) for their quick and thorough response to the issue.
So, if the issue is resolved, why am I writing this piece? Well all of those early L30s are still out there as they didn’t require them to be returned. They didn’t send out replacement power supplies with the replacements. So, all those early units are potentially still on the market and it is a matter of time until an unscrupulous seller tries to pass off one of these older models as the newer version as stickers with serial numbers are laughingly simple to fake. What is needed is a way to tell new from old that cannot be faked. Luckily there are two. Unluckily, both require some degree of take-down.
One tip off may be the power supply, make sure your unit comes with a Topping labeled supply rather than an aftermarket supply. This is suspect though as a good unit may have had a power supply misplaced or an older unit may be packaged with the power supply from the original purchase. We need a 100% method to prove the generation and safety of the unit in question.
The least invasive method to determine the generation of board is to remove the two outer screws (Torx T8 or 2.5mm allen) on the rear face, and the two screws holding the rca jacks to the rear plate.
A word of caution here; the screws into the RCA housings are long and screw into plastic so be gentle and know that if you do this very many times it may well strip the threads and require some epoxy in the channels to grip. Also the dust covers on the RCA jacks will hold the rear face in place as well so those need to be removed and then the rear face should fall off with a gentle tap.
Once the rear face is removed you should see what looks like this:
The difference in old and new units is immediately visible in the lower left side with the photo above showing the newer version. The issue with the originals was lack of a grounding point between the board and the case so the gold pin seen just above the PCB on left is that ground contact that was added to the post 2011 revision boards. Below are larger images of pre and post 2011 samples.
Presence of the pin is enough to insure post change construction, but doesn’t assure you that the board matches the serial number on the unit. To do that, you need to fully disassemble the unit which leads us to Method 2.
Method 2 – Board Removal
To remove the board from the unit, you will need a small flat-head screwdriver, a torx t8 or 2.5mm allen wrench, and a set of needle nose pliers.
This method requires removal of the two outer screws on the rear face, but the two holding the RCA to the faceplate can be left alone as the rear faceplate and board will slide out the rear of the unit as a single piece once the volume knob is removed and the screw behind it taken off.
Removing the volume knob is a simple but delicate operation due to the front face’s glass construction.
Place the tip of the small screw driver so the blade is parallel to the face plate and slide under the volume knob and push straight in so the body of the driver lifts the knob. Make sure not to push the tip downward as it will gouge the glass. Once the tip of the blade is under the edge of the knob you can use the edge of the case to leverage and lift the knob. Once the knob starts to move you should be able to pull it off by hand.
Once the volume knob is removed, there is a nut that must be removed before the board can be pushed out the rear of the case. A pair of needle nose pliers help here as there is little room to grip the nut due to the ledge on the faceplate. Once removed, pushing on the shaft of the volume knob should push the rear faceplate and board out the rear of the case.
With the board removed from the case, the board revision can be checked by looking at the corner nearest the volume knob as seen below. This is a older board with a serial that begins with 2006 on the unit and the L/N showing 2006 on the PCB.
Below is the newer board showing a 2012 L/N and a corresponding serial that starts with 2012.