Page 31 - Hi-Fi World (January 2020)

REVIEW

At left the input bias adjust selector for V1-V4 output valves, bias adjusted to put the needle into
the black sector on the meter scale. Then a Triode / Ultralinear lever switch, volume control (centre)
headphone socket, Standby switch, Tape switch and rotary input selector at far right.

three-head recorders. on/off rocker switch being mounted important for those living in remote
Finally, at far right is a four- on the left panel side panel near areas – Northern Australia mining,
position rotary input selector for the the rear of the chassis, so space is Borneo logging etc. – where we
four line inputs at rear purposed to needed at left to reach it. This makes found the market for valve amps was
match CD players and most modern turning on and off awkward in the peculiarly strong.
sources. Low output sources like lower shelves of a rack. Best to leave
low-gain external phono stages some space all around the amplifier SOUND QUALITY
match, since setting high sensitivity – especially above – to allow air to With Ultralinear/Triode options and
(H) on the rear panel switch makes circulate because its heaters consume three feedback settings there are
the Stereo 40 MkIV more sensitive 76 Watts in total. potentially six amplifiers to review
than most transistor amplifiers. Although the Stereo 40 MkIV here! It can get very confusing
The rear panel carries solid uses a classic Ultralinear output very quickly. But with our Martin
gold plated phono sockets for the stage, the rest of the circuit differs Logan ESL-X hybrid electrostatic
inputs and tape output. Loudspeaker from past convention. Two low-mu loudspeakers, connected with Chord
terminals, 8 Ohm and 4 Ohm, are 6SN7 double-triodes offer front Company Signature cables to the 4
also gold plated and sturdy, accepting end gain on each channel through Ohm tap and an Oppo BDP-205D
bare wire, 4mm banana plugs or cascode operation, whilst another Universal player to play CD, plus hi-
spades. Nestling between these ins two provide phase splitting (for resolution digital from an Astell&Kern
and outs lies the small Sensitivity push-pull). Icon say the use of four AK120 player, basic differences were
switch. Power comes in from the identical high quality triodes eases obvious enough to distill out.
mains via the usual IEC socket, the fault-finding and replacement issues, An Isotek Evo3 Mosaic Genesis

The rear carries heavy duty, gold plated phono socket inputs (left) and equally solid, gold plated loud-
speaker terminals for 4 Ohm or 8 Ohm loudspeakers. Above are large in-house designed and built
output transformers at left and right, with mains transformer at centre.

www.hi-fiworld.co.uk JANUARY 2020 HI-FI WORLD 31