Old Guard Technics Amplifier – 1979 Top Model DC Amplifier (DC Amplifier), cost 198,000 yen, or about $ 900 that year. From some admirers of this company I heard that Technics used to make good amplifiers, but those devices that periodically came to me were more and more later and played one “soapier” and “wadier” than the other. I have already formed a strong opinion that all Technics power amplifiers are like that.
Opening the top lid, I immediately realized that this is not the Technics that I have seen before – this is definitely something different. An attempt to find documentation for this device was unsuccessful.
There is nothing to it, except for photos and characteristics, there is not even an elementary user manual, not to mention a service manual, and even on paid sites. I only found information that the SU-V10 model is a reissue of an earlier and well-proven SU-8099 integrated circuit, for which there was no problem finding a service manual.
The circuit is really similar, but there are differences in the field of offset and thermal stabilization of the final stage. The SU-V10, unlike its predecessor, has the inscription “New Class A” on the front panel – this is where, apparently, the discrepancies have gone.
On the amplifier board there are covers with the inscription “Synchro-bias circuit”, under which are hidden 4 germanium diodes, a pair of ceramic capacitors and a thermistor – this is not exactly what the SU-8099 has. About the quiescent current on the Japanese Internet, they write that it works practically without it, but there are no switching distortions.
In general, the quiescent current set 20 mA – at this value the minimum constant level at the output (about 10 mV), and 20 mA, in my opinion, is “practically nothing.” I tried to set the quiescent current less than 1 mA, but I still can’t hear the distortion – their New Class A circuit works well.
UM technical parameters according to the manufacturer’s data:
The design of the amplifier is solid: a solid chassis, a shielded mains transformer tightly filled with a compound, 4 capacities of 15000 uF, combined in pairs, all blocks are closed with steel covers – inside the amplifier looks like the design of the internals was developed on purpose.
The layout is in the spirit of that time: the blocks are located more or less competently, but the shielded wires to the RG and other control elements stretch through the entire body from the inputs, although some switching elements are located in places and are remotely controlled from the front panel (using a flat cable).
The buses for the power supply and the output bus are interestingly made – they are flat and tightly pressed against each other through dielectric plates less than 1 mm thick. The signal path from the output transistors to the speaker terminals is quite short. The final stage has two pairs of transistors with a cutoff frequency of 50 MHz, in a TO-3 metal case.
The set of commutation is standard: two inputs for players with MM- and MC-heads, two line inputs and control of two tape recorders. The timbres are switched off, with the possibility of choosing the frequency of adjustment, loudness is present, also switched off. Subsonic filter and HF limiting are available.
There is also an incomprehensible Straight DC / Via Tone switch – apparently, when the timbres are turned off, the amplifier is a DCA, when the timbres are on, the signal goes through the coupling capacitor.
The RIAA corrector is discrete, as I understand it, but without any special bells and whistles. Shielded very well.
The output terminals are screwed, but designed for a thin wire, bananas cannot be connected. All RCA input jacks are gold plated.
Having hooked up the amplifier to my audio system, I precipitated a bit, to be honest. This device doesn’t just sound good, it sings! Immediately you can hear the thoroughbred sound of a serious amplifier – high resolution, UM has built a wide and deep musical space inside which musical events unfold, the sound is completely disconnected from the speakers, it is soft, but at the same time with very good microdynamics and powerful emotional presentation.
The tonal balance is neutral, the frequency response in the low-frequency range is flat, the infra-bottom is not cut off. Macrodynamic performance is normal – not outstanding, but quite decent. The amplifier has a fairly high declared output power – 160 W / 4 Ohm per channel, the power supply unit may well provide it, so the musical resolution does not suffer with increasing volume and the frequency response at the edges of the range too.
I will not single out the connection to vinyl as a separate item, but I will simply say that the corrector is so-so, so Technics did not manage to shine with super-quality analog sound – the corrector plays well, the sound is pleasant and not tiring, that is, listen to it from the built-in corrector it is even possible – it is not bad, but the external one will still be asked for in the audio system after some time.
An excellent device, both in sound and in construction and design. From my point of view, it claims to be one of the best vintage integrated PA. RIAA mid-level corrector for built-in – you can listen, but it does not pretend to be a separate component. The amplifier is quite rare, it is very difficult to find it in good condition. There is no documentation for it.