tda Posted July 2, 2004 Report Share Posted July 2, 2004 Hello all, Recently I bought a Sony D-NE800 CD/MP3/Atrac3Plus Walkman. I know, I know it isn't related to MD, but still may be interesting... The player performs OK, but (as you probably already know) it has a crippled low-power output on the headphone line. It is now ! 1.5 mW + 1.5 mW ! for Europe, whereas everyone else enjoys a normal 5 mW + 5 mW output. I studied the topic and taking in consideration that probably Sony doesn't use completely different technology in MD and CD players, decided to take my device apart and see what I can do. Of course it is quite painful to lose your warranty right after you bought it, but if you do it carefully nobody will ever even notice So, I discovered that indeed, the D-NE800 output is a Headphone Amp (17020B - of which I found nothing in the Inet) used priorly by Sony in the MZ-N10. I saw earlier complains about Sony's European crippling strategy and decided to hack the unit to a normal one. As I understood from previous posts, the hack is based upon the short-circuiting a pair of resistors which are 'killing' the power. There would be no problem for me to find them on a MZ-N10 device (with the service manual at hand), but having absolutely no info about D-NE800 makes it a little bit of a problem... So, if anyone knows anything about the HP Amp chip (probably AN17020B or AN17020A) or has any technical info on the D-NE800 (a service manual would be very nice), I would be glad to hear from you. Quote Link to comment Share on other sites More sharing options...
tda Posted July 10, 2004 Author Report Share Posted July 10, 2004 I finally decided to take my Walkman apart. An guess what I found? The HP amp is a AN17020B - which is a totally unknown type and even has a different package (16-SOP) type than AN17020A-VB (16-Quad)... I found the Right and Left channel outputs using the MZ-N10 service manual and was surprised to find that the resistors connected in series with the headphones (the ones which are usually used to cut down output power) are only 6 Ohm! This was quite disappointing, because I suspected much higher values, which would mean a bigger cut-off in power. As I already mentioned, the output power on D-NE800 is 1.5 mW for Eruope. I shorted those two 6 Ohm resisors, so now I suppose I have around 2 mW of output power, which is still too low. IMHO they changed the 5 mW / channel amp (AN17020A-VB) to a lighter 1.5 mW / chanel version Anyways, the request for a adequate service manual still remains open... tda Quote Link to comment Share on other sites More sharing options...
skyther Posted July 11, 2004 Report Share Posted July 11, 2004 16-SOP.... o.O No rolling op-amps for you then. Quote Link to comment Share on other sites More sharing options...
jadeclaw Posted July 11, 2004 Report Share Posted July 11, 2004 @tda: Well, the only solution is a low impedance headphone with a good efficiency. By bridging the 6 Ohm resistors, you nearly doubled the power, when using an 8 Ohm headphones, with a 4 Ohm load, you tripled the power. The limit can be the amp itself, if it can't deliver the current necessary to drive such a load. Advice: Take the modified rig to the shop and try a bunch of headphones on it when buying new phones. Quote Link to comment Share on other sites More sharing options...
tda Posted July 11, 2004 Author Report Share Posted July 11, 2004 Actually have a pair of Sony MDR-ED31 headphones with a 16 Ohm / HP impedance, 108 dB / mW. So I think I raised the power by about a third of what I had (had: 16 + 6 Ohm, 1.5 mW, now: 16 Ohm, ~ 2 mW). Just a question: are there any GOOD HPs anyone would recommend? I mean lower impedance or higher sensitivity? Another interesting thing... When I listen to a recording without any EQ, I think I have full output power, but when I set the EQ to another preset (i.e. ambient, soft, hard, custom), it seems like something is cutting down even more power. Any ideas on that? tda Quote Link to comment Share on other sites More sharing options...
tda Posted July 12, 2004 Author Report Share Posted July 12, 2004 I just thought: what is it Sony changes that US and Europe units' HP output power differs more than 3 times (5 mW vs 1.5 mW)? It has to be something else than the mentioned resistors, because they are only 6 Ohms... I found this in the specifications for D-NE800: Output (at 4.5 V input level) ... Headphones (stereo minijack) Approx. 5 mW + Approx. 5 mW at 16 Ohm (Approx. 1.5 mW + Approx. 1.5 mW at 16 Ohm)* * For the customers in Europe I figured that to get a 1.5 mW instead of 5 mW output power @ 16 Ohms, you have to use at least 37 Ohm resistors ... or am I wrong? Any ideas on this? Of course, a service manual should resolve the issue tda Quote Link to comment Share on other sites More sharing options...
Solid Snake Posted July 18, 2004 Report Share Posted July 18, 2004 Sorry to go a tad off topic here, but I've always wondered why they do that to European CD players. Can anyone shed some light on the subject for me? Quote Link to comment Share on other sites More sharing options...
jadeclaw Posted July 18, 2004 Report Share Posted July 18, 2004 French safety regulations. Reason: The little kids turn up the volume too far, damaging their ears. Years ago, I castrated a cheap tape walkman for a friend for exact that reason. His daughter had cranked up the volume to the limit and that thing was definitely too loud. Quote Link to comment Share on other sites More sharing options...
tda Posted July 21, 2004 Author Report Share Posted July 21, 2004 So, as I understand, nobody is willing to help... Pity... Quote Link to comment Share on other sites More sharing options...
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