Classe DR-5 Preamp and DR-5 Power Amp Reviewed
HTR Product Rating
- 4 Stars
- 4 Stars
- 4 Stars
Disagree with our product rating? Email us and tell us why you think this product should receive a higher rating.
Networking is all that keeps a journalist well-informed, and my network never fails. A couple of American manufacturers have, time and again, alerted me to new brands or models worth investigating, and it is to one of them that I own the introduction to Canada's Classe electronics. It's pronounced 'Class A', which is wearing one's heart on one's sleeve, eh? I was told that they had few if any sonic rivals, that they were priced realistically (by prevailing high end standards) and that they deserved all the exposure they could get.
The latter may have something to do with the people from Classe being really swell guys, but that shouldn't influence a purchase or a review. This favorable reaction to the DR-5 pre-amp and DR-8 power amp was repeated on this side of the pond when a particular high end retailer phoned me -- out of the blue -- to sing their praises. After much haranguing, begging and general whingeing, I managed to borrow the combination and I'll tell you from the outset that none of the claims have been exaggerated.
High end conventions have dictated that we're faced with a cluster of '19in rack-mountable' boxes with styling which veers from the wholly functional to the seriously sleek. The latter includes companies like Krell and Rowland, while the former is epitomized by Audio Research. Classe follows the functional approach, only it is accomplished with quite the panache of ARC, whose 'lab look' has become a style in itself. If anything, Classe has blundered along Croft lines by opting for a crummy typeface which detracts from the other initial impression: Classe gear is built to no-compromise standards.
If the styling doesn't reinforce any notions of perceived value, then a quick twirl of the knobs or a flick of the switches will tell you that you are, indeed, in the presence of luxury goods. The DR-8 is your classic, 24kg high-steel-content lump bearing handles and an Aragon-like on-off switch, but the finish is flawless. At the back are the requisite inputs and outputs, but with a couple of serious inclusions to suggest that the company has no time whatsoever for mere fripperies. Among the fittings at the back are a choice of balanced (XLR) or single-ended (phono-style) inputs, IEC three-pin mains socket, toggle switches to select stereo or mono operation and the most outrageous speaker terminals this side of welding tags. Classe fits their power amplifier with ¬bolts¬. Not screws, not binding posts but bolts which require a 7/16th inch spanner, supplied with the amp. They'll accept bare wire or w-i-d-e spade lugs, and you can torque those mothers till your deltoids collapse.
The lid is removable to allow you to select between balanced and unbalanced operation (I have friends who consider all audiophiles as unbalanced, for what it's worth). Inside, it's your basic gorgeous construction, designer components and acres of heat sinks. The Classe DR-8 ran cool-ish even when driving sub-2 ohm loads, so stability should not prove to be a concern. I doubt if many of you would wish to restrict its breathing by hiding it in a cabinet, so allow floor-space of 482x380mm (WxD); height is 180mm.
The company describes the DR-8 as a high current/high voltage design, inspired by the dearer flagship, the DR-9. Ignore the 70W/channel rating; the DR-8 has the drive, slam and resistance to clipping that suggests 200W/channel, easily matching the Aragon 4004 for sheer kick. The two channels share only the mains input and primaries of the massive power transformer, each channel's power supply being separately rectified and filtered by proprietary capacitors rated for 80,000 uF in total. Overkill is the recipe throughout -- those speaker terminal bolts become more and more symbolic of the Classe -- and the company states that
the output section's power transistor capability is 2kW or 128 amps per channel. Peace of mind is in the form of a single mains fuse and a DC protection circuit.
The DR-5 has one of those nicely symmetrical, sensibly attired faceplates designed for instant familiarity (in a right-handed world). Between the handles, from left to right are four primar rotary controls: input selector, mode, balance and volume. The first chooses phono and four line inputs, three identical (CD and two auxiliaries) with 'tuner' padded down by 6dB to accommodate what Classe feels to be a tuner's typically higher output. (It also came in handy when using a D/A converter known to be a few dB more generous than the norm.) The mode selector offers stereo, reverse, mono and L-only or R-only. Balance has a no-nonsense
centre-detent, while I counted 32 steps on the volume control including full-off. All of the rotary controls have the kind of feel you'd expect of high caliber gear, so forget the Nikon rattle; this stuff is Leica silky.
The four toggles select tape/source, phono/bypass (for direct feed of the phono signal past the input selector, tape and mode switches), polarity inversion and mute. Polarity inversion is
something I've been championing for years, so the DR-5 immediately gained a spot in my heart, while the mute is an absolute necessity with this pre-amp as their is no mains on/off.
Classe argues that the DR-5 sounds best only after it's been powered on for a while, and they're right. It took over four days to burn this in from cold and then it took a good couple of hours after switch-on for the '5 to sound its best. The DR-5 is unlikely to make your electricity meter go into a spin, so leaving it on at all times is advisable.
At the back is a row of gold-plated sockets and a switch to select between m-m and m-c operation. Loading is accomplished automatically through the use of self-adjusting impedance
circuits, but m-c gain is user selectable. Classe supplies a kit of resistors to allow the user to vary the factory setting of 24dB gain (in addition to the m-m gain of 35dB) in 2dB steps; the
range is 20dB-40dB, so you'd be hard-pressed to find an m-c cartridge which can't be accommodated. The resistors are fitted internally into gold-plated press-fit sockets, and silver solder is supplied for users who wish to make the change a permanent one. This technique, while less convenient than a rotary selector on the front panel, is about as practical and thorough a method as you could hope to find.
The DR-5 also sports and IEC mains input and the choice of balanced or single-ended operation, and my sample also offered a pair of 'convenience' mains sockets which I thought were a super-no-no in the UK. Not that any blue-blooded audiophile would use convenience outlets to power their ancillaries if they were allowed...
Operation, aside from fine-tuning the m-c stage, is virtually instinctive. All you must do is make allowances for the lack of a mains switch on the pre-amp by employing the mute toggle whenever changing plugs at the back. Despite the Spartan appearance, the DR-5 offers everything one could require for full control of a complex system, with the exception of a second tape loop and record-out facility. I'm not too bothered though, because I consider tape and VCRs as secondary sources, so a few quid spent on one of QED's marvelous switch boxes or passive pre-amps will turn the Classe's lone tape loop into a mixing desk if so
The Classe devices were substituted in turn for the Audio Research SP-14 and Gryphon pre-amps and for power amps including the Aragon 4004s, Beard P100 monos and Lumley 150s; the rest of the system included the Basis/SME V/Koetsu Urushi analogue source and the CAL Tempest II SE and Marantz CD-12 CD players, Apogee Divas and Stages in bi-wire mode, Celestion SL700s and Sonus Faber Electa Amators. I prepared for the sessions by burning in the Classe DR-5 before doing any close listening; the DR-8 was already primed.
Read more on Page 2.