How to remove EU volume limit from Sony personal CD players D-NE300, D-NE270, D-NE500, D-NE510, D-NE700, D-NE710, D-NE800, D-NE900, D-NE10, D-CJ501, D-NF400, D-NF600

After hunting eBay for a while I finally found an interesting personal CD player with onboard CDText display: an Aiwa XP-ZV616:



Testing it out and downloading the user manual revealed a couple of surprises:

• It's a clone of the Sony D-NE300 - I already knew it was a Sony-era product but hoped it was based on one of the higher-end models
• The headphone output is heavily restricted - This is a European model originally sold here in the UK

I'd already bought a Sony D-NE1 (hate the lack of decent equaliser) and I'd forgotten it also suffered from the EU power output limit (to prevent hearing damage). The Aiwa user manual confirms a feeble 1.5 mW output on European models compared to 5 mW everywhere else. This means that in a noisy commuting environment or when driving high-impedance headphones (like my Sennheiser HD580s) it struggles to deliver a decent volume.

Searching online I found the D-NE300 service manual to see if there was some hidden service menu where the region could be changed over but no. Although it mentions soldering a connection on the circuit board to enter a "Test Mode" it doesn't actually say what options are available.

Digging further into the service manual I wondered if there was some physical difference on European models. There are plenty of extra components on the circuit board for car kit (CK) models but only one extra component stood out as being fitted to just European/UK models:



This R817 "short chip" looks like a surface mount resistor and basically just a solid connection between tracks. It creates a connection to pin 81 of the system controller chip (IC801). The service manual states the pin isn't used but I was suspicious. I decided to take the risk and break the connection to see if it would convert my player to an international model.

The service manual shows the location of all the components and on the XP-ZV616/D-NE300 this resistor block is on the underside of single circuit board, right next to the controller chip:



Zooming in it's even labelled as being for EU/UK models only. Note on my circuit board had a slightly different layout in this area (see next photo below):



I won't cover opening the player as this is in the manual. Also I should remind you this is at your own risk, I'm not liable for any damage to your player!

I used a soldering iron to heat each end of the block and when the solder had softened I could push the block off the board. Then I checked there were no traces of solder left fouling the connection or other components. Here's my board after removal, note the different position due to extra unused terminals:



Put the player back to together and result! With small earphones it's now painfully loud at 50% volume and the player can drive my big Sennheisers to a decent volume for home listening (although distorts a little on the two highest volume steps).

I've seen many people complained when these players were new and I'm shocked nobody else figured out this modification at the time. I did find a reference to a physical mod on a Russian site but no documentation of it.

Most people have long since moved to MP3 players and smartphones but hopefully there's still a few people out there who'll be excited to unleash their European spec players with this mod.

I've also downloaded the service manuals for other D-NE models from the same 2003/2004 era and found many share the same system control chip and Europe-only connection to pin 81. Later NEx20/NEx30 models sadly aren't so simple so I can't say if there's a similar mod for them but the service manuals are out there, elektrotanya.com seems to be one of the few sites that offers the manuals for free.

D-NE270

This model uses the same board as the D-NE300 so same technique to remove the volume limit.

D-NE900 / D-NE10

The D-NE900 service manual helpfully shows the location. The D-NE10 manual doesn't but it uses the same board.



D-NE700 / D-NE800

On these models the block is on the opposite side of the board from the controller chip:



D-NE710

On this model the service manual doesn't show the position but I've highlighted in red where I think the block will be:



D-NE500

Any optional connection to pin 81 isn't documented but I've highlighted in red where I think the block would be:



D-NE510

This player uses yet another variation on the same chips but might be a bit tougher to remove the connector due to components around it:



D-NF400

This player follows the same method as most above, an extra surface mounted resistor block (R817) creating a connection to pin 81 of the controller chip (IC801). There are many other component differences on the board but they must be for the radio (other regions use different frequencies and different sized steps between stations).

D-NF600

As above for the D-NF400 except the component is labelled R804 and on the opposite side of the board from the controller chip:



D-NE20 / D-NE820 / D-NE920

Service manual shows a single 220k resistor is placed in a different position depending on whether a EU or non-EU model. I think the board and components are very small so not something I'd want to attempt with my basic soldering skills.



D-NE1

I haven't been able to get the service manual for this model yet so I opened up mine to check the circuit board. It appears to have exactly the same controller chip but the surface mounted components are much smaller than on the China-made D-NEx00/x10 models above. I don't think I'd want to attempt any mods to this board even if I could see a component to remove.

D-CJ501

This earlier MP3-only model has a volume restriction only in France and uses an extra connection to pin 50 of its controller chip (IC801). It's component R828 in the service manual, incorrectly labelled as for the Car Kit model (CJ506CK) on the diagram on page 13.