 This is my first review that will be published in HFOL, so I want to write a few words about my listening sessions and my reference system, so that you can have some knowledge about it. I am no “professional” reviewer of audio equipment, and I do not have that extensive listening experience as the Editor in Chief of HFOL has. That is the reason I will try to evaluate the tested devices in a broader group of friends audiophiles. This is not a group like the Krakow Sonic Society, by far not, but I hope equally agile in terms of meetings and tests. The main listening basis will be my audio setup, consisting of a CD/audio DVD-V player Bluenote Koala Tube, tube preamplifier Manley Labs Shrimp, power amplifier Linn Akurate A2200 and loudspeakers Bowers & Wilkins (B&W) 804S. Cabling comes from Linn, Mogami, Turtle Spirit and AudioNova. The system is at home in a room with a surface of around 22m2, medium damped, and functioning as a normal living room. I own only a spore of an analog system (my vintage Pioneer turntable stood in the basement for years), so my evaluation of the analog LP domain can only be binary – sound present or no sound present. )
The first device or better said, set of devices that reached me for testing is a tube preamplifier and a tube power amplifier made by the US company Rogue Audio. The preamplifier is called Ninety-Nine and the power amplifier Stereo 90. In HFOL we have already tested the monoblocs from that company, the M-150. The tested devices are from the same line as those monoblocs. The Stereo 90 has an identical front panel and the preamplifier matches the power amp in design. Despite the low price tag both items were made in USA. So the company does not lower standards. SOUND The Rogue Audio system reached me almost directly from the airport after being imported to Poland. It did not play before, even for a minute. So after unpacking both boxes (oh my back…) I connected them to the player and loudspeakers and put on a disc letting it burn in. But some characteristics of the sound were obvious from the very first moment. The system sounded very ‘analog’ – without any harshness or raucousness in the sound. And this during burn-in, and usually then all the harshness is served clearly. After a few days of lazy listening I started the actual test. I was also visited by a few colleagues (due to the size and weight of the system it is barely transportable) and their observations were coherent with mine. )
During transportation also the triode-ultralinear mode switch was broken, so I conducted all test in the ultralinear mode that was always on. The power amplifier also has separate outputs for 4 and 8 Ohm loudspeakers. The change is not very easy, but I will write about that later. My loudspeakers have a minimum impedance of 3.2 Ohm, although they were described as 8 Ohm by the manufacturer, so I listened to both settings. I did not hear substantial differences so I decided to conduct the listening tests on the 8 Ohm outputs. Those settings remained constant for the whole session. Somebody said that the KT88 tubes, and those are in the power amplifier, sound with a sharp and detailed sound. The Rogue sounded completely different. Like I mentioned before the main characteristic was the analog sound. In general the tonal balance was correct, but there was a slight warming of the sound. I think, that this is the result of a slight rounding of the attack and preference for the midrange and upper bass in the sound spectrum. Those are no big departures from linearity, but it is audible. This, and the splendid saturation, made the vocals sound phenomenal on almost every disc I listened to, starting with Kari Bremnes from the disc Over and By (Kirkelig Kulturverksted, FXCD 293, 2005, HDCD) through Rufus Wainwright Release the Stars (Geffen, 602517301610, 2007, CD) to Radiohead or Pink Floyd. Such playing, devoted from harshness, makes also the less good recorded discs, or recordings, where ‘harsh’ sounds are inherent, sound a bit softer. So no disc should irritate. Jazz ensembles, small orchestras or soft commercial music will sound just fantastic. Listening to harder music, like Tool 10000 days (Sony BMG, 82876819912, 2006, CD) we can complain about the lack of some ‘edge’. The top part of the sound spectrum can be called ‘tubey’. It is vibrant, pearly, but a bit behind the midrange. In comparison to my reference system the resolution of the treble was a little lower. This translated in the sound stage, that had smaller dimensions, it was fully between the speakers, the outlines of the instruments and musicians were a bit blurred and the ‘air’ escaped a bit from between the players. Talking about the stage – the happenings on the first plane were privileged compared to the rest of the scene. This was especially well audible on the disc Murder Ballads Nick Cave & the Bad Seeds (LCD Stumm 138, Mute Records Ltd, 1996), where Nick stood a few steps in front of the loudspeakers and his band behind the line of the speakers. )
Let’s talk about bass. It sounded soft, with good control and slightly emphasized upper range. It does not reach very far down and it does not have that hellish might. In the March from the first Suite from Holst Op.28 No 1 (DVD-V recorded from a 24/96 file created from LP, Telarc, by a professional recorder Tascam DV-RA1000) there are a few mighty hits in the kettledrum. Rogue did not fully manage to reproduce the might of those strikes. Those sounded as if the kettledrums would have no resonators, and the skin would be spread on an open rack. Here the solid state power amplifier from Linn fared better. On the other hand the timbre and the control of the bass were on a very good level. Of course I tried each element apart. After splitting the system, I think that the power amplifier performed better. In a setting with Manley Shrimp it still keeps some warming of the transmission, but the resolution of the treble and power of the sound were better. If this is possible, the midrange was even more saturated. On the other hand, the preamplifier connected to my transistor poweramp slightly thinned the sound. In general the Rogue system may be an interesting proposition for people searching for a sound that can be listened to for hours. I think that it will show its best by jazz music, chamber music and quieter popular music lovers. Those who prefer the ‘hard sounds’ and symphonic music may feel slight insufficiency. Anyway, looking at the system in context of its price – it is hard to achieve full universality, I may also not have been able to unleash full potential of this set, because my loudspeakers are not very ‘tube loving’ and I was not able to change the operation mode of the power amplifier. DESCRIPTION )
The preamplifier Rogue Audio Ninety-Nine has a typical design of this company. The front panel of the quite large enclosure is made from a piece of aluminum 15mm thick. The aluminum front is screwed to a metal partition that is a unity with the bottom and back plate. In the mid part of the front there is a half circular excision where the volume, source selector, gain selector and IR receiver are placed. On both sides of the excision there are buttons, on the left a power button, with a bright LED on top of it, and the mute button and on the right side the mono and the tape loop button. The back plate has five RCA inputs – four line level and one MM/MC phono input, there are also two RCA outputs – one for the power amplifier and a line level one for a tape recorder, and the latter can be converted to a variable output by two dip switches inside the preamplifier. All RCA sockets are of very good quality, solid, gold plated and screwed to the plate. Besides those we can find a turntable ground terminal, a headphone socket 6.3mm and two Cannon type sockets for connecting the external power supplies: one four pin and one six pin socket. Interesting enough one lead carries low voltage, as in the external power supply enclosure there is a small toroidal transformer (Chinese make) and two rectifying bridges, and the second lead carries normal mains current to a second, larger, toroidal transformer with a single secondary winding placed inside the main enclosure. The circuitry of the preamplifier is based on three PCBs. One PCB is mounted vertically near the back of the enclosure. All RCA inputs and outputs are soldered to this PCB. Also the source selector is placed there, connected to the knob by means of a plastic rod. From this PCB the signal runs via long cables to the volume potentiometer (black, motorized Alps) placed at the front panel. The remaining elements are mounted on one big PCB that covers almost all the bottom of the enclosure. On this PCB we have the power supply for the preamplifier with four capacitors 39000F each. The main amplifying circuit is based on four 6SN7/6H8C tubes. The tubes carry no markings, what can suggest China as their place of manufacture. The passive elements look very nice, especially the output capacitors – M-Cap Supreme. )
The front panel of the Stereo 90 power amplifier looks exactly like that from the monoblocs M-150. It is a thick aluminum slab with a round opening in the middle where the power switch and a blue power led were placed. The back panel is fairy simple – we find there single loudspeaker terminals for each channel, gold plated and accepting all kinds of cables, but rather small and placed close to each other, what can impair the mounting of thick audiophile cabling. Near one of the sides a stereo RCA input socket is placed, looking a bit worse than those in the preamplifier. We find there also an IEC power socket and a mode switch (broken in the tested unit).
PŁYTY PROSTO Z JAPONII  |
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