Rotel RA-935BX Amplifier
The Rotel strategy in marketing value-for-money hi-fi separates in the UK has been very successful. Basically the units are built in the Far East, where costs can be kept down, but details of the designs and the choice of 'audiophile' components are worked out in this country. The RA935BX integrated amplifier (?199'95) continues this strategy and takes to new extremes that other audiophile notion, minimalism. Just about everything that could be dispensed with has gone: no tone controls, filters or loudness contour (of course); a single printed circuit board with well designed star earthing and skeletal direct-route signal paths to mimimize hum and interference; most surprisingly, no pick up cartridge input, which will devastate vinyl/analogue enthusiasts.
What we are left with is a stereo power amplifier rated at 40 watts-per-channel into 8 ohms, with a volume control and five switched inputs all quoted at the same 210mV line-level sensitivity. I t follows that the front panel is very bereft of knobs. The two rotary input/source selector switches, one for "Listening" and the other for "Recording", are located at the righthand side for ergonomic correctness (if you are righthanded). The volume control knob is at the centre and is one of these concentrically ganged types allowing the LIR balance to be adjusted if required. Along at the left-hand end we find the power on/off push-switch and red LED indicator, a standard headphones jack-socket and a second push-switch labelled "Speaker Remote".
This is a clue to the rather unusual way that connections to two pairs of loudspeakers plus headphones are arranged. One of the two pairs of loudspeaker terminals on the rear panel is labelled "Remote Speakers" and these are the outputs controlled by that front panel switch. The other terminals are labelled "Direct Speakers" and provide a purist non-switched outlet for the main loudspeakers. However the headphones socket is also unswitched and so headphone listening will normally be accompanied by sound from the main speakers (at the same shared volume setting). "Hence", as the instructions leaflet suggests, "if you are a frequent user of headphones, you may wish to connect the speakers to the Remote terminal posts all the time". Only then will it be possible to enjoy private headphone listening: I hope that makes everything clear.
The terminals are of a robust type accommodating either bare wires or 4mm banana plugs. They share the rear panel with seven pairs of phono sockets for the five inputs, CD, Tuner, Auxiliary, Tape 1 and Tape 2, plus recording outputs for Tape 1 and 2. Any source can be recorded to either or both tape machines, while listening to that source or any other, but dubbing only works from Tape 1 to Tape 2.
Despite its modest price, in this audiophile context, the RA935BX shows no signs of any cost cutting. External finish and construction are fine, with a matt black fascia panel, a wrap-round top cover perforated overall for free air circulation and padded circular feet. Internally the large pcb occupies the whole base area except where cut-outs make way for the strategically distanced mains transformer, large UK-sourced 'slit foil' capacitors and the output devices mounted on substantial heat sinks. Care has been taken with symmetrical layout of the left and right channels and matching the pcb track thickness to the maximum current carrying requirement.
In practice, the heat sinks did a good job and the amplifier ran quite cool after many hours of use.
In fact the sound quality tended to be thin and peaky when switched on from cold. Once warmed up, there was still a feeling of lively sound projection but, far from being aggressive, this gave a measure of presence which I found very agreeable. At the same time there was enough transparency and unveiled treble to make the music reach the ears directly and cause the 'equipment' almost to disappear. This immediacy was particularly rewarding on small-scale recordings, such as the songs sung by Anne Sofie von Otter, when the singer and piano seemed to be 'in my room'.
High resolution and clarity were evident with large-scale musical forces too, and combined with a fine feeling of width and depth to produce a pleasing degree of realism. Extreme bass was present but very slightly reticent, and thereby indirectly contributing to the overall clarity. Dynamic range seemed unusually wide. Measurements were in agreement with the technical specification and confirmed such subjective findings as the unit's high current capability, which allowed musical peaks ample headroom, low distortion and inaudible residual noise.
It is perhaps sad to see an integrated amplifier having no provision for vinyl disc reproduction, but of course this can be added by introducing a proprietary pickup preamplifier between the LP player and one of the line inputs. The conservative power output rating of 40 watts-per-channel was actually exceeded in my tests but may still seem on the low side for realistic reproduction of full orchestra, pop or rock music. Nonetheless to my ears the power available should be enough to satisfy most domestic listening requirements except perhaps in a very large room or with decidely inefficient loudspeakers.
This amplifier lives up to its 'audiophile' description and provides at a very affordable price the kind of sound quality we normally look for only from much more exotic systems. I t should, however, be teamed up with decent source units and loudspeakers having no tendency to exaggerate treble.
