Fallow,
I to mnie zastanawia, mysle ze ze wzmacniaczem nalezy pobyc troche, stad ja nie dam sobie reki uciac za te wszystkie przelotne odsluchy w jakich bralem udzial, natomiast odnosnie transparentnosci rpx vs yamamoto (nie slyszalem) znalazlem cos takiego, osoby ktora miale yamamoto, rudistora rpx-33 i GCHA przez kilka miesiecy:
I have owned yammy, RPX-33 and GCHA for more than 2, 6 and 10 months respectively, as I bought them new and had experienced the burn-in effect on each amp. To my ears, the signature of yammy and GCHA changes rapidly after two months of continuous use.
They will sound better and better after continuous use, and change of wires does improve a lot on them, especially the GCHA, which is a transparent amp, cables matching (power cords and interconnects) is important, I could tweak the GCHA to sound even slower than the yammy like analog to suit female vocals, or tweak to sound very dynamic and fast to play complex music like rock, pop, blues, classicals. To me, GCHA is a keeper for me to audition any new cables I acquired, and it\'s very smooth and liquid as a solid state amp. I like to use RS-1 and MS-Pro with GCHA, as it presents a creamy, warm and melting listening experience for me. With recent acquisition of oritek X-1, UE9s with GCHA I heard slightly more micro details in the recordings.
The yammy is sensitive to the interconnects use, and in fact my virtual dynamics david 2.0 RCA has the best synergy with yammy over my kimber select. However, the david 2.0 is nearly the price of yammy... If you listen to a lot of jazz and vocals, I would strongly recommend yammy to you. Yammy is particularly friendly to jazz and vocals, it\'s spectacular. It demonstrates great rhythm and pace and tone in the mid range. I have been enjoying it with almost all my headphones, including the high impedance cans like HD600, DT990. The previous assumption that it\'s suitable for low impedance headphones is no longer true. However, as I said yammy needs a lot of burn-in time, with HD600, the sound changed from very sweet (before 40 hours), to slightly veiled and warm (100-400 hours), and now it\'s transparent and more open, like opening the windows for the first time after a long winter (over 500 hours, i.e. lately).
With UE9s, before 130 hours usage of yammy, the bass compartment sounded like it was blocked and not open, after 130 - 400 hours, UE9s sounded good but with a slight emphasis of midbass hump. And now more than 500 hours, the UE9s sounds very natural and transparent (but not as transparent as RPX-33, so it depends on your musical tastes and preference), very musical and romantic.
Of RPX-33, it\'s the most transparent and detailed amp out of the three. And I won\'t call it a neutral amp because it has a rich full tones in its own. The sound also doesn\'t changed much from swapping of power cords, I reckon it\'s due to a better power supply in RPX-33. With HD600, I heard the best HD600 like I never heard it before. However, to my ears and tastes, GCHA has more "euphonicity" over RPX-33, more tube-like sound than the colder RPX-33.
http://www.sgheadphones.net/index.php?showtopic=8202&st=0&gopid=97121&#
