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Yamaha C1000

The largest in the Yamaha range, delivering 86W per channel (both driven) into two switchable pairs of loudspeaker outputs, available on spring loaded locks for ease of connection. The mains lead is 2 core, and feeds through to two switched and two unswitched mains outlet sockets. An unusual coaxial socket is provided for 75 ohm FM aerial connection but fortunately this is duplicated with 75 ohm and 300ohm FM aerial terminals. (Yamaha should change the, socket to a more normal type.) Phono sockets throughout are used for audio connections, and inputs include pick-ups 1 and 2, auxiliary 1 and 2, and input and output connections to two separate tape recorders. Front panel controls allow monitoring of either recorder or, alternatively, copying from either one to the other. Phono break points are provided for insertion of external equipment immediately prior to the main amplifier. Two earth terminals are provided on the rear. Pick-up input 1 has three switched impedances of 28k ohms, 41k ohms and 62k ohms (as measured). The receiver is very heavy and is mounted in a large wooden case with a metal ventilation grill, and even when pushed hard it only attained a warm temperature. The general styling is most impressive, but the ergonomics are highly personal and clearly many will find the controls fascinating and helpful, whilst others will at first be confused. All the tone controls are ganged and have 11 stepped positions on a horizontal click stop slider arrangement, which worked well. The loudness control was similar, allowing its effect to be gradually increased as desired. The balance control was a centre indented normal horizontal slider. The turnover frequencies of the tone controls can be set at 250 or 500Hz for bass, and 2.5kHz and 5kHz for treble. The rumble filter cutting at 12dB per octave rolls off steeply below either 20Hz or 50Hz (excellent). The treble filter is switchable at 7kHz and 14kHz for 3dB points. A rather small rotary volume control is provided but a separate slider microphone gain control is also incorporated. An additional slider operates FM muting level. A row of neat lever paddles select inputs, operate tape functions and also mono/stereo combinations, and loudness switch. Stereo jacks are provided for microphone and headphone connections and adequate volume was given for the latter. The tuning mechanism is a delight to use and the dial accuracy superb. Signal strength and tuning meters are provided.
The amplifier's reproduction quality was clearly good but it must be judged by the highest standards, because of the price. Some bass sogginess was clearly audible to all of us. The treble end was liked. Very extensive IM sweep tests were made which confirmed the results of the listening tests. In particular they showed a relatively poor IM performance at the bass end. The half power bandwidth for 0.1 % was very good, extending to at least 20kHz. Harmonics distortion and SMPTE IM distortion measured well, but the latter began to increase slightly at low levels. The damping factor was excellent. No DC output problems were noted (output circuits relay protected). The signal to noise ratios throughout were excellent. The volume control tracked rather poorly below -30dB. The remaining controls tracked well. The tone controls all provided excellent variation. The pick-up input amplifier had an excellent clipping margin and its output level was well compatible with that of the tuner. All the input and monitoring functions are FET switched to avoid clicks. Auxiliary and tape in/out impedances and sensitivities were very compatible (nb.but not directly with DIN standard equipment).
The signal to noise ratios of the tuner were superb. The distortion measurements were in general very good, but full deviation of R-L was rather poor. But in practice this is not too serious in this case. The crosstalk measurements were average and adequate. The frequency response was very good whilst the MPX filter was excellent. RF input sensitivities were superb. Adjacent and alternate channel selectivities, image response, IF breakthrough, capture ratio and AM rejection measurements were excellent, RF IM ratio was good. The limit threshold also measured well. The tuner section gave excellent results on both the test and normal broadcast programmes. The tuning knob when touched switches off AFC for ease of tuning.
This is a very expensive receiver and whilst it gives a very good quality, a few others were cheaper at a discount. Stylistically, though, Yamaha must be strongly commended, and the electromagnetic compatibility was remarkably good. It can be said to be fair value for money and can be recommended if you are not concerned with price.






This article featured in the Hi-Fi Choice 'Consumer Guide' 1976 and was written be Angus McKenzie. We thank Hi-Fi Choice for their kind permission to display this review.