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Reviewer: Srajan Ebaen
Source: Zanden Audio Model 2000P/5000S
Preamp/Integrated: ModWright SWL 9.0SE
Amp: First Watt F-1; First Watt F-2 [on review]; 2 x AudioSector Patek SE; Decware Zen Taboo; Canary Audio CA-308s [on review]
Speakers: Zu Cable Definition; Gallo Acoustics Reference 3
Cables: Zanden Audio proprietary I²S cable, Stealth Audio Indra (x2), Zu Cable Gede to subwoofer, Zu Cable Ibis, Zu Cable Birth on sub; Crystal Cable Reference power cords; ZCable Hurricane power cords on both conditioners
Stands: 1 x Grand Prix Audio Monaco four-tier
Powerline conditioning: 2 x Walker Audio Velocitor S
Sundry accessories: GPA Formula Carbon/Kevlar shelf for transport; GPA Apex footers underneath stand, DAC and amp; Walker Audio SST on all connections; Walker Audio Vivid CD cleaner; Furutech RD-2 CD demagnetizer; WorldPower cryo'd Hubbell wall sockets
Room size: 30' w x 18' d x 10' h [sloping ceiling] in long-wall setup in one half, with open adjoining living room for a total of ca.1000 squ.ft floor plan
Review Component Retail: $5,995

KR Audio's mighty Kronzilla has already appropriated the moniker the beast from the East. Perhaps DeHavilland might retort with the pest from the West? That's because this company has consistently made such excellent sound at tradeshows that it's become a predictable pest for any journalist hoping for news. Of course, consistency in excellence is news and enviable news at that. It's just not the sort which hectoring novelty hounds with short memories notice too much while they're hustling down the aisles in search of flashy new product introductions. Into the same non-flashy file go DeHavilland cosmetics. This outfit has always eschewed glitz in favor of a far more yeoman approach. For the Ios stereo amp or integrated, that means no gleaming chrome à la Art Audio Carissa, no numerical volume readout or remote à la Bel Canto SETi40 of yore - two 845 amps I've had through in the past.

Instead, there's plenty of visible screws, absolutely massive sheets of bent chassis metal powder-coated in industrial grey, volt-meter access holes, ventilation holes and bias adjustment controls including an offset meter. All that makes for comprehensive functionality but not necessarily air-brushed centerfold allure.

Everything is practical and thoughtful, however, including the spring-loaded bias engage rocker switches that revert to out-of-circuit position by themselves to avoid possible damage should a user try to play dumb and leave them engaged during signal. The rear apron sports a very useful ground-lift control marked in film strips rather than silk screen, and a plaque indicating replacement fuse values and tube layout. The ground lift switch has been pulled in deliberately to keep it as short as possible and prevent it from snapping off during manhandling the amp's considerable 66 pounds into position.

Even the excellent Cardas Rhodium binding posts have been additionally marked with a spot of red paint for the hot terminal just in case a user suffers poor-enough vision to not make out the black-on-black markings of the terminal plate. The mains fuse is easily accessible just as it should be.

This whole impression of real-world robust HiFi appliance rather than finicky audio toy extends to the 25wpc power output rating and the fact that this amp was developed using 88dB B&W 805 mini monitors to assure sufficient drive into common speakers rather than left-field esoterica catering to weak-chested SETs.

Supplied with Electro-Harmonix 6SN7s, RCA 6AU5s and Chinese 845s, the Ios is an inverting amp whose beam power tubes turn on instantly for their customary bright white/yellow glow and come on song about 30 seconds later when the blue power LED on the fascia lights up to confirm that the high-voltage delay circuit has run its course. And beware the high voltages. We're talking in excess of 1000 volts DC on the rails! Do not remove the bottom plate to poke around the innards unless you know what you're doing. Definitely don't remove the bottom plate while the amp's connected to wall power or within 3 minutes after power down. Regular users of course will never be aware of the lethal voltages operating within. They'll simply use the amp as intended: to listen to music with. Nothing dangerous about that - except perhaps failing to show up at work on time (or at all).

Under the hood, we see premium Swedish Lundahl output transformers that compete with the Electraprints used in DeHavilland's $7,795/pr 845G monos on price but allow mounting inside the chassis due to smaller size. Besides extended HF response, this also makes for an ultra-short hook-up wire connection of 1" to the tubes. The transformer in the upper right of the photo is a single-turn filament transformer for the low-impedance 6AU5 power pentodes (horizontal sweep tubes from the early televison era) which here are run in triode mode to drive the 845s. The two chokes provide for inductive filtering -- power conditioners are not recommended to prevent curtailing of dynamics -- while three more transformers hide underneath the tranny cover: a single-plate hi-voltage power transformer; a dual-filament tube heater-supply transformer; and an auxiliary transformer for the bias controls, meters and other accessories.

This transformer segregation based on function avoids the cheaper but standard combination transformers commonly used which can cause magnetic cross-coupling of circuits that DeHavilland prefers to keep completely isolated. The #194 wedge-based lamps [below] on the massive bayonet-style 845 sockets make for "good-sounding fuses" according to lady designer Kara Chafee. The 4-section Lundahl output transformers are hard-wired to the outputs and optimized for 4-ohm loads. 8-ohm speakers create a higher plate load for reportedly better sonics than via a separate tap. Special 16-ohm connection is available at the time of order placement for special applications.

One solitary Jensen coupling cap [above, gold/yellow] in the entire audio circuit means a DC amplifier input. Partnering preamps should neither pass DC nor produce a high turn-on thump (in the latter case, the preamp should be powered up prior to the Ios).

A very short custom order menu for the Ios stereo amplifier includes Cardas gold/Rhodium binding posts and matching RCAs for $200; select Sylvania 6SN7GTA/Bs for $100/pr; and a circuit modification to accept KR Audio's 845 [$400] which run their heater current about 15% lower than the stock Shujuang 845s, also available as more upscale B (graphite) and M (metal-plate) versions. Those Chinese 845s are variably rebranded as New Sensor, Valve Art or Super TNT.

Because 90-day tube warranties begin ticking the day DeHavilland (and not you) buy them, the company provides generic Shujuangs with the amp but recommends you relegate those as back-up tubes and buy 845s of your choice [ca. $150/pr] with full warranties from or other reputable tube suppliers.

A tube cage as is available for the 845G monos is currently under development for the one-box sibling. There are already five female banana plug receptacles on the top of the amplifier. These banana jacks are wired together and then wired into the chassis ground. According to marketing director George Kielczynski, "the conductive tube cage, when attached to the chassis, acts as an RFI shield to lower noise, as well as a protective shield". The Ios stereo or integrated amp arrives in grey power coat and with an option of black or silver faceplates, with inlaid enamel dress stripe and company logo [the latter red on black or either black or red on silver]. Designer Kara Chaffee mentioned that beside B&Ws, she's driven a friend's 86dB KEF Cantatas, older Green Mountain Audio 3-ways and JMlabs on the Ios. She is supremely confident that any three-way of sane efficiency will be driven not only loud enough but properly by this direct descendant of her 845G monos. For my upcoming review of this Soviet tank-reminiscent amp, I'll use my 88dB Gallo Reference 3s for its main missiles. The 101dB Definitions shall mostly be used to report on noise (or lack thereof) into such high-efficiency loads, for those rare souls who'd run high-voltage 25-watt amps into speakers that'll at best consume 4 watts.