MichaelBeardy Posted July 12, 2005 Report Share Posted July 12, 2005 Bad news for those of us with Euro-region NH900s.... I was poring over the service manual last night as I was doing some backups on my PC and discovered that the European volume limitation on the NH900 is achieved by more than just a change in the destination code in the firmware. There are some extra resistors on the mainboard in the audio output stage which are specific to the Euro-region model - the other regions have these replaced by a zero-value resistor (or a shorting link if you prefer).There's a 22-ohm and a 47-ohm resistor wired in parallel between the output stage and the headphone/line out socket on each channel. This gives an effective resistance of 14.98 ohms - which with a headphone impedance of 16-ohms (or thereabouts) represents a significant restriction on output power. Sorry folks... When connected to a high impedance input - like when used as a line out to an amplifier, which will have an input impedance of maybe 47k-ohms, the exra internal resistors will have virtually negligible effect.I don't dispute that altering the region setting in the service mode may have an effect on output levels, but that ain't all there is to it. It gets me wondering if there are similar resistors in the second-gen Hi-MD models too. Haven't looked at the service manual for the RH910 yet....Peace,Michael Quote Link to comment Share on other sites More sharing options...
hobgoblin Posted July 12, 2005 Report Share Posted July 12, 2005 must say that i never understood where this stuff came from. but then i had never heard of it before i started to visit this place so... Quote Link to comment Share on other sites More sharing options...
Latexxx Posted July 12, 2005 Report Share Posted July 12, 2005 It's about some stupid French legistlation which they managed to make Europe wide. Quote Link to comment Share on other sites More sharing options...
KJ_Palmer Posted July 12, 2005 Report Share Posted July 12, 2005 Well, at least its good news about the line level output being more or less unaffected (if that's correct...?).I must admit I dont have any problems with the output volume of the 'hacked' Euro NH900 or NH600 - they seem to even drive my Senn HD580 headphones pretty well on their own, though I do usually use them a with a headphone amp. Is there an easy, definitive way to test the volume output of an audio unit, eg. with a test signal and a volt meter, or is this all just speculation, as it's beginning to seem... Quote Link to comment Share on other sites More sharing options...
ROMBUSTERS Posted July 12, 2005 Report Share Posted July 12, 2005 ya but the extra transistor means the output is lower on a physical hardware level. You might need an external pre-amp to bring it back up to the original signal Quote Link to comment Share on other sites More sharing options...
MichaelBeardy Posted July 12, 2005 Author Report Share Posted July 12, 2005 Yeah,To be honest I'm not sure that the power output difference of 3mW as opposed to 5mW makes a huge difference at the listening end - it'd probably amount to a couple of dBs - you'd hardly notice. My (standard Euro) NH900 comfortably drives my MDR-EX71s to very loud levels - I normally listen somewhere around 8-10 on the volume scale which probably equates to less than half a milliwatt from the amp, so plenty of headroom. I can also listen at reasonable volumes through an old pair of Sennheiser HD420s which are big, supra-aural phones and not very efficient - so for me at least, the power output really isn't an issue. I don't think I'd want to listen at full power (3mW) for any length of time - it'd be just too loud for me - so who really needs 5mW?Having said that, having looked at the service manual, if you were handy with a miniature soldering iron, and familiar with anti-static procedure, it wouldn't be too hard to solder a couple of bridges across the offending resistors to bring the output back up to the 5mW. But like I said - I'm really not sure it would make that much difference.I like to listen to my music on my HiMD player, but I don't particularly listen to my HiMD player - if you understand what I mean. Peace,Michael Quote Link to comment Share on other sites More sharing options...
MichaelBeardy Posted July 12, 2005 Author Report Share Posted July 12, 2005 By the way, I did have a quick squint through the RH-910 service manual today and couldn't see any "region specific" resistors, so I'm guessing that the volume capping on that unit is achieved through the service-mode firmware settings. It'd make sense really - it must cost Sony less to make one mainboard for all markets and then tailor it through the firmware setup, rather than having to have a separate production line or production run with different components added for Europe or wherever.Peace,Michael Quote Link to comment Share on other sites More sharing options...
Prof.OND Posted July 15, 2005 Report Share Posted July 15, 2005 Maybe it's a stupid question but here goes anyway...Does the apparent presence of supplementary resistors mean that they are used?Or to put it in other words:Might it not be possible to pass them (the resistors) by by adjusting some values in the service mode? Quote Link to comment Share on other sites More sharing options...
MichaelBeardy Posted July 15, 2005 Author Report Share Posted July 15, 2005 Maybe it's a stupid question but here goes anyway...Does the apparent presence of supplementary resistors mean that they are used?Or to put it in other words:Might it not be possible to pass them (the resistors) by by adjusting some values in the service mode? ←Not a stupid question at all......but the resistors are hardwired in series with the headphone/line-out, so sadly no way to bypass them through service mode. You'd need to get down and dirty with screwdriver and soldering iron.Having said that, I would still argue that there isn't going to be that much audible difference between 2.8mW and 5mW. I find a volume setting of 8-11 on my Euro-capped NH900 more than adequate for most applications - and my ears aren't exactly hyper sensitive - I'm 41, and my ears have taken a bit of wear and tear over the years - can't hear bats anymore. Very occasionally I might turn up the volume to 15-20 for a really kicking track - but most of the time I just want to enjoy comfortable listening levels. I don't think I'd ever need all of the 2.8mW per channel the NH900 can put out.Peace,Michael Quote Link to comment Share on other sites More sharing options...
Chomik Posted July 16, 2005 Report Share Posted July 16, 2005 I live in Poland and I obviously have got the European version of NH600. I've hacked it, there was a slight difference, but still I have to amplify the music around 22-24 to listen to it in the street (on original Sony in-ear headphones). I am a clasical musician (clarinetist) and I guess I have preatty good ears.. Can I do something with it? Quote Link to comment Share on other sites More sharing options...
MusicBringer Posted July 16, 2005 Report Share Posted July 16, 2005 I have to amplify the music around 22-24 to listen to it in the street (on original Sony in-ear headphones). I am a clasical musician (clarinetist) and I guess I have preatty good ears.. Can I do something with it?←Hello Chomik, the best thing you can do is throw away those original Sony in-ear headphones. Get youself a decent set of headphones. They even sell 'em in Poland lol. Search the forums for advice. There are many good ones to consider, and you don't have to spend huge amounts of money . Quote Link to comment Share on other sites More sharing options...
Chomik Posted July 17, 2005 Report Share Posted July 17, 2005 Get youself a decent set of headphones. They even sell 'em in Poland lol. Search the forums for advice. ←They are on the polish market, of course! But they are so bloody expensive.. It seems to be the only solution, though. Thanks for your advice MusicBringer! Quote Link to comment Share on other sites More sharing options...
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