The [portable] amplifier is connected to D-25[S?] by a connecting cable. The cable's connectors, at both ends, are size ' 3.5 mm ', also called ' mini '. The cable designation is : - 3.5 mm to 3.5 mm - or - ' mini ' to ' mini ' . One end of the cable goes to the ' LINE OUT ' jack of the D-25 and the other to the ' IN ' [or ' LINE IN '] of the amplifier. The headphones are plugged into the ' OUT ' [or ' LINE OUT '] of the amplifier.
I recommend this connecting cable :
http://www.aloaudio.com/jumbo-cryo-v2 . Call ALO Audio -
http://www.aloaudio.com/cables-en/portable-cables-ipod-imod-solo/mini-to-mini-en-2/ and order this " wire " [cable] to be at least 25 cm long. The line out jack of the D-25 is on the left side and back. To reach the [LINE] IN of the amplifier which is in front, the connecting cable should be about 25 cm long so that when the cable is connected it is a bit loose. To be sure, and the error would cost the money, take a tape measure and see what should be the length of the cable.
'Slee Novo' would do no justice to the sound of D-25. ' ALO the National ' would be a much better choice.
http://www.aloaudio.com/thenational . I would say that it represents the best value for money as a portable amplifier. If you could afford it ' ALO the Continental ' is even a better choice because its slightly fuller and "tube-y" sound compliments and fits ' the chilled ' japanese sound / tuning of the D-25/D-250 perfect. But it is more expensive.
http://www.aloaudio.com/the-continental-v2-en .
Reviews of these 2 portable amplifiers :
The National
1.-
http://www.touchmyapps.com/2012/05/13/alo-the-national-headphone-amplifier-in-review-a-new-class/ .
2.-
http://www.head-fi.org/t/610270/alo-the-national-is-a-work-of-art-check-it .
3.-
http://www.head-fi.org/t/605602/alo-audio-the-national-the-continentals-younger-sibling-review-comparison-to-rx-mkii-ttvj-slim .
4.-
http://www.audioexcursions.com/files/alo-audio-the-national-solid-state-portable-headphone-amplifier-review.html .
5.-
http://www.headfonia.com/the-sequel-alo-audio-the-national/ .
The Continental
1.-
http://www.head-fi.org/t/578866/alo-audio-the-continental-portable-vacuum-tube-amplification-review .
2.-
http://www.headfonia.com/the-sweet-sound-of-tube-the-alo-continental-amplifier/ .
3.-
http://www.audioexcursions.com/files/alo-audio-the-continental-portable-vacuum-tube-amplifier-review.html .
4.-
http://headfonics.com/2012/04/the-national-the-continental-alo-audios-finest/ .
My view of the Sennheiser hd-580 to hd-650 line of headphones is that they have a darker sound presentation. Hd-595 high frequencies are also not well extended and that is a bit unfortunate because the high frequencies of D-25 are great, smooth and clean, joy to listen to. D-25's chilled 'asian' sound is to our ears a bit more penetrating than is for us the more accustomed mellow 'european' sound, but it is pure and beautiful and with excellent dynamics. D-25 was created by the audio engineers of Sony to play real music, that means acoustic and primarily classical. It excels with the old music like the renaissance or the baroque musical sounds and with the country, the folk or with the 'a capella' singing. To me the acoustic albums of Emmylou Harris sound great on this player and even "The Wrecking Ball". D-25 is not interested in playing heavy metal, techno, rave, heavy beat, thumping and banging. If you can afford it think about pairing Beyerdynamic headphones with your D-25. Maybe D-T70 250 ohm version. Check 'for sale' forum on head-fi, you will save money. Look for re-cabled headphones with ' Moon Audio ' or 'ALO Audio' cable.
For the technical help with D-25 or for the problem/repair help see 'Kaosun's vintage cd player service bulletin on 'head-fi ' .
http://www.head-fi.org/t/530633/kaosuns-vintage-cd-player-service-bulletin .
Good luck, let me know how you and your D-25 are doing.
