product: Rotel RA-921 integrated amplifier
manufacturer: Rotel hi-fi
approximate price: ECU 170
Let's do a mental exercise. Think back to your early hifi days. Forget about the beauties you have today, just go back to...whatever it was that you used then for playing music. Whatever it was you were truly proud of. In my case, an ECU600 music centre from ITT.
If you were in that dire situation now, what would you buy? Sure, we have plenty of cheap half-decent CD-players, and a turntable we almost- steal from the second-hand market. Speakers? What with Missions, B&Ws and KEFs all-singing all-dancing around us. Amplifier? Gee, which amplifier? All you have for your meagre ECU150 is this Pony and that Sioneer, or perhaps a Yamlips... and the little Rotel RA-921! Yep, a Rotel integrated for the price of ten CDs! Hell, if you combine it with a second-hand tuner you pick up for ECU25 you're still cheaper off than with just about any mass-market receiver. And you'd still have a Rotel! Looks better than the music center I had to start with?
The amplifier-under-test is a very modest 2x25W integrated. And yet, Rotel did not really skimp on useful features. For one, there is a phono input. This is a good move, even at the bottom of the market, as many many people still use their turntable. Or would use it, if possible. Then there are three line inputs as well as one tape loop. Two, non-defeatable tone controls enable you to compensate for less-then-perfect speakers with a subtle operation of +/-6dB at the frequency extremes. And finally there's a switched headphone socket, something I had to do without for, oh, the past ten years! This little guy has a solid and rigid feel to it, weighing a considerable 5kg. The front panel is a thin plate of black anodised aluminium, and at the other side we find sturdy speaker connectors that accept bare wire or 4mm banana plugs. Good one!
The internals are typically Rotel, and in fact the circuit board reveals itself as being the one that also served in last year's - more expensive - RA-920AX and RA-930AX, with the 930 model having some extra components not fitted to the cheaper siblings. The transformer is a small EI-core, followed by one bridge rectifier with - nice detail - ceramic capacitors over the individual diodes. Then follow two 6800uF capacitor reservoirs, and what appear to be voltage regulators for the preamp stages (I couldn't get a clear look on their writings). The power amp is fully discrete; the line preamp is a single TL-072 opamp; and the MM phono input is handled by one NE5532 IC opamp, with the full RIAA correction in the feedback loop. Surprisingly, the signal capacitors throughout seem to be polystyrene types: as Thorsten would say, you can hardly get better! Internal and external build quality is excellent for the money, and would not even disgrace a component costing twice as much. Protection of the amp and its load is offered by no less than four internal fuses. This Rotel won't be an amp that self-destructs and then calls for a $100+ repair bill...
The (English-only) manual states that the RA-921 "may have low power, but will nevertheless provide excellent sound in a small room and with very efficient speakers". You can't blame Rotel for not telling you how to use the beasty. And you certainly can't blame a brand which invites you in its manuals to "Enjoy the music!".
There was no way I would try this amp on my cherished electrostatics. After, all it would only be a waste of time. Neither of both components were made to work with the likes of each other. So I took to a thirteen years old pair of Rogers LS-1 two-way bookshelf speakers. In their era they were low-budget speakers, but rather surprisingly I found their sound to be essentially neutral, large, and wide-open, once a thin balance and slightly too excessive (yet clean!!!) treble were reined in with the tone controls on the Quad 34 preamp. In fact, these little speakers produce a sound I could live with: compared to the competent entry-level champions of these days, such as the B&W 302 or the Mission 731, they just do their thing better!
With a sensitivity of only 85dB/1W@1m these speakers demand quite some driving, but on the other hand their impedance never is lower than 6 Ohms or so, meaning that this driving job is not a hard task.
Or so I thought. During the listening tests the 921 seemed to be working very hard: the sound was rather undernourished, lacking some body and having a softish and slightly subdued bass. Treble was slightly bright, but not really annoyingly so, and the midrange was characterised by a certain reticence and lack of presence in voices. The amplifier was not overtly coloured, but still its sound bore more resemblance to Xerox copies of actual instruments and voices than to the real thing. And while detail seemed to be fairly high for such a product, the midband sounded a bit clouded. Pushing it with rock music gave somewhat of an overdrive character, electric guitars considerably hardening up. When used with headphones - a small Sony MDR-70T and a large AKG K-400 - this character remained more or less the same, being only marginally better than the sound one can get for example direct from a CD-player's headphone output. Good points were a wide and open sound stage with a modicum of focus, although the lack of midrange presence did not allow vocalists to really stand out from the mix. Depth was absent, but we got a tonal balance that was neutral enough not to cause fatigue. With less-busy classical music the Rotel fared better, rendering the music in an enjoyable way. This indicates that the less it is put to work the better. Maybe more efficient speakers are indeed mandatory?
Then the phono stage. Stuck with only low-output moving coil cartridges, as you know, I ran my old 0.3mV Denon DL-301, on an ancient Thorens TD-160, through the RA-921, listening through the AKG headphones. With the Summer season really beginning and an awful lot of traffic at the nearby airport, this was the only fair option to sample the phono input. Surprise number one: it worked. And surprise number two: it worked very well indeed! Mentally subtracting the sonics of the line stage from what I heard now, the phono input had a rather nice midband, sitting on a fullish and rolling bass, and a more or less OK treble with only some splashiness. There was fine detail, and the sound seemed sufficiently open and airy. I can imagine first-time buyers using the 921 for a while, upgrading to something better later on, possibly keeping the small Rotel as an outboard phono stage!
Another interesting point was that I could compare directly to my Cyrus One MkII. This is an integrated amp of 2x30W which I bought back in 1988, for ECU380 or so. At that time it had audiophile credentials, and reviewer Martin Colloms called it "a perfect amplifying brick". It served me well for eight years, although it could sound muddled and compressed on 'difficult' speakers such as my Magnepans or Quads. How would the dirt-cheap Rotel compare?
Right from the onset it was clear that the Cyrus sounded more composed and more consistent altogether. It handled loud passages better (but not that much better), maintained a more even tonal balance towards the frequency extremes, with a sweeter treble and indeed better transparancy. On the other hand, the Cyrus' image was clearly narrower, and spacially more muddled. Still, of the two the more expensive oldie had a higher listenability and indeed crosses the line between just-audio-components and great-music-makers.
Finally I moved the RA-921 to its intended habitat: Yes, I bought the thing to be used as a replacement for a fifteen years old 70W Technics amps that chose to blow-up completely. In this system, which is rather non-critical with an old Sony CD and big efficient Peerless kit speakers (not even in a real stereo setup!), the Rotel surprised by sounding more punchy and vibrant than the more powerful Technics seemed to do before! Some serious midband colourations were evident, but I'd attribute these mostly to the large paper cone woofer/mid driver in these old-fashioned Peerless loudspeakers.
I have to admit the RA-921, as tested, does not meet my own basic criterion for hifi: I want complete listenability, and in addition to that a minimum of transparency, of realism. The 921 falls short in both disciplines. Not by much, but it does nevertheless: It is lacking a bit in transparency to be faithful to the source, and with the speakers used it can sound a bit too aenamic to remain entirely free of fatigue (the Peerless being a rather peculiar exception). Now this does not make the Rotel a bad amp. On the contrary! At this lower- than-low price it still has to be one of the very best offerings around. It is only so that, again, at this low price there simply are no components that consistently do make the right noises.
It is very well built and hardly costs money - and let's not forget that truly fine phono stage - but in the end a real hifi buff may be better off saving more money, immediately jumping up one grade in amp-land, perhaps to the Rotel RA-931 or 935BX. This will then be money well-spent.
I still feel a good budget-system can be built around this amplifier, but prospective buyers should proceed with utter care, matching the other components to this Rotel so as to exploit its inner strenghts while not revealing its relative weaknesses. I have a gut feeling that the B&W 302 loudspeaker, with its high sensitivity and rather full sound, may make a specifically good pairing with this little amplifier. As such a qualified recommendation is not out of place here.
© Copyright 1998 Werner Ogiers for TNT Audio Magazine, https://www.tnt-audio.com