Mixed Signals
Sydney Morning Herald
Monday November 17, 2003
Hybrids are almost always exotic, whether they're flowering plants or hi-fi components. Vincent's new SV-236 integrated amplifier is a dual hybrid - it combines two very different technologies, the thermionic valve and the solid-state transistor, and is built in China to a German design commissioned by a Swiss company.
An amplifier designer who mixes valves with transistors has two options. One is to use transistors in the input stages and valves in the output. This gives the warm, slightly rounded sound of an all-valve amplifier but it's expensive, requiring three large transformers and at least four expensive output valves that need to be replaced at regular intervals.
Vincent takes the second option, which is to use transistors (A1386A/C3519A pairs) in the output stage and valves in the input. This has several advantages. There's a single power transformer and the input stage uses small triode valves. If these valves need to be replaced - and they rarely do - it's only $60 for all three. The sound quality of this type of hybrid design isn't as mellow as an all-valve amplifier, or even a hybrid using valves in the output, but it's still different to an all-transistor design.
The reason for this sound difference is disputed. Some engineers claim it's due to something called microphonics - where a valve picks up sound energy in the room and converts it to an electrical signal, which it adds to the music. Electric guitarists use valve amplifiers specifically to exploit this effect. It enables them to create unique sounds and sustain notes that otherwise could not be sustained. Others claim the difference is due to the way an overloaded valve behaves compared with an overloaded transistor.
Vincent is understandably keen to advertise its use of valve technology. It has placed one of the SV-236's three 12AX7A valves behind a small circular window in the front panel, simply to draw attention to it. Behind the valve is a semi-circle of highly polished metal that accentuates the valve's bright red glow, making it much brighter and even more obvious. The window isn't entirely for show. It also houses an infra-red sensor to pick up instructions from the amplifier's remote.
The symmetrical layout of the front panel, with the bass and treble controls on the left of the window and the input selector and volume controls on the right, gives the Vincent a retro look that's in keeping with the technology. The tone-control circuitry can be bypassed to give a cleaner audio signal and there's a loudness contour circuit for a more natural frequency balance at low volume levels.
To our ears, the Vincent didn't have a warmer or fuller tonal quality than the solid-state amplifier we used for comparison, but the music played through it seemed to sound somehow more elegant and graceful, so it rapidly became our preferred amplifier of the two, even though the volume control scraped slightly as it turned and there was no channel-balance control. These were the only niggles in an otherwise fine package.
Info file
Vincent SV-236 Integrated Valve
Stereo Amplifier
RRP: $3000
Seagulls Imports & Exports Pty Ltd
15 Pamela Grove,
Lower Templestowe, Victoria, 3107
(03) 9858 3531
info@eav.net.au; www.eav.net.au
© 2003 Sydney Morning Herald