I just got this cd player by accident. It was manufactured in 1994 and made in Thailand.I have searched in the website but it shows on the model Optimus cd 3400 and most people is looking for and want to be owner as well as have some review in strereophile. Anyway, Optimus cd 3450 is one bit with 8 oversampling and have line out and phone out. The appearance is quite old fashion and very big and heavy. No antiskip in this model. However, when i listen the music, it is amazing.
I have tried with Koss kc 35. The sound is very open and bass is very huge. Normally, kc 35.,the sound is quite flat and a little bit dark in the midrange but with this cd player, the sound is very open, airy and more musical with sound looking like full size
I have tried with HD 600. This cd player can drive HD 600 with volume at 2-3 form 10 scales. Unbeliveable. The sound is more airy and more musical than My Zhaolu connected with home cd player. The sound is very natural.
Finally, I have tried with ViewSonic( raptor). Sound is open but the bass is less than KOSS and HD 600. The sound is not change too much comapred with normal portable cd player.
Anyway, maybe by tomorrow, i will have tried with my grado rs 2. In addition, the retail price is bAHT 4,800 but I get more cheaper than retail price due to old model and the store want to sell fast.
I just want to share my experience because i am very surprising on the quality of old portable cd player that can compare with my home use system. If you find one, you must to buy it.