Packing a lot into a small space but doing it in style, Paul Rigby reviews Densen’s new B-175 integrated amplifier.

Back in 1992, Densen released its first ampli-fier, the DM10. “When that arrived, it cost around £1600” said Thomas Sillesen, founder

of Densen. “That was a huge price for an integrated. One of the most expensive of its type at the time. Twenty years later, we wanted to make another, top of the line, inte-grated. You don’t sell truck loads of integrateds at this price so we partly made the B-175 just for fun.” That wasn’t the principle reason for creating the new amplifier, of course, there were practical reasons too. “There are a lot of users who want a good amplifier but don’t want a large footprint. It’s a small machine on the outside but big on the inside. It’s the antithesis of those big American amplifiers you often see. There are also some customers

who live differently, they have a more minimalistic design. A larger system will take over the room. We can supply pre and powers for those who want it though,” said Sillesen. Speaking of pres and powers, the B-175, offering 125W of power and available in albino (natural brushed aluminium) or black, is forged from respected Densen technologies: you will find a combination of the B-250 pre and a slice of the B-330 power amp plus the B-350 monoblocks within its 440x310x64mm sized, 16kg chassis. There were challenges when merging these technologies, though, “Such as the interference between the power and pre amps and achieving a good design in such a small space. Each channel is surface mounted so each power amplifier is the size of a credit card. Hence, the circuitry is squeezed but that has the benefit that you can make

the circuitry faster. There’s less radio interference in this way.” Despite the lack of space, Densen has been careful about isolation. Even in terms of how the toroidal power supply is oriented has had an effect. Densen engineers have measured the noise floor when the power supply was installed, twisting the transformer to find the lowest reading. There is also a brief hark back to the original DM10. “The wires used internally are copper with silver coating and Teflon isolation. We used these cables back in the DM10. New old stock,” said Sillesen. And as for those who scream that pre and power separates are the audiophile route, Sillesen has strong views on that, “If you look at performance, I don’t think there is a compromise. The alternatives would be a pre and two monoblocks which

Style master

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would end up costing £7,500 or more. In that respect, the separates are far more expensive.” One interesting point of the design is the lack of a variable resistor, potentiometer-based volume control, a widely used, common choice for many hi-fi components. Trouble is, it never performs very well at low volume, only at full volume. It also produces a channel imbalance at low volumes, “ALPS produce the most well known system which we also use, the RK-27, so do Naim. Although we have since tweaked our supply because it’s not precise at low level. On the B-175, we use a precise attenuator, which only has one resistor in the signal path at any one time, making it effective but simple. There is also a far greater choice of resistors in this system now than there used to be to truly make this system usable. We have utilised a remote-friendly, 200-step, system controlled by a microprocessor. It’s an example of our no-compromise approach,” said Sillesen. Externally, the recessed heat sinks add a touch of class, although the initial reason wasn’t aesthetics but efficiency, “When you cut a heat sink you normally have to brush it to make it look nice. Done in this way, you don’t have to because they are covered which makes the amp cost efficient while still looking nice,” said Sillesen. The Densen also offers 5.1 and 7.1 channel surround sound preamp options via an internal board under as an optional extra. Densen supply

a value-for-money SP-01 board for £300 while the better sounding, more refined SP-02 is £800. You can also buy a separate Moving Magnet phono amp plug-in card (£150) or a DIP switch-controlled, dual Moving Moving/Moving Coil board for £225. The phono boards replace the Line 1 input which demands that you move two jumpers to effect the Line 1 to phono board transformation. The cards are normally a dealer fit but the operation is a simple one for any DIY fan or those who are used to inserting boards into the back of their PC computer. If you don’t want to use the surround slot for surround hardware and you have no need for the MM phono card then you will have

available room and power to install a plug-in DAC. Called the Fabel DAC (£350), it was only introduced at the recent Munich show. It supports 24bit/192kHz via an S/PDIF electrical input. An external power supply can be added and an electronic crossover is an option too. There is no headphone socket

and only one pair of loudspeaker outputs, so bi-iwring requires special cables.

SOUND QUALITYComparing the Densen to my reference system, especially the bass dominant Icon Audio MB845 Mk.II monoblocks, was an enlightening experience. On the question of those lower frequencies, the Icons projected a big, dominating bass front that allowed percussion and bass guitar to have a full part in the rhythmic portion of the mix. What I didn’t expect, was to hear the Densen place bass in a similarly important position. OK, the Densen is a solid state machine so what’s so newsworthy about that? Because of how the Densen implements

the lower frequencies. Some solid state amps create a Godzilla-like bass performance that not only unbalances the overall presentation but also imposes itself, leaking like ink on blotting paper, into the midrange and treble. Here, the Densen bass stood its ground. It knew its place and only infused its rich, powerful bass response where you wanted

"it did provide, however, both air and space that allowed the mids and treble to breath eas-ily, providing more room for the music to manoeuvre"

Much of the internal space is occupied by a toroidal power transformer and blue power supply smoothing capacitors. The circuitry uses miniature 'surface mount' components. Additional boards can be inserted to cater for both MM and MC phono cartridges.

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VERDICTA stylish, minimalist design, the Densen B-175 offers a combination of low frequency power and higher frequency finesse.

DENSEN B-175 £5,500Kog Audio +44 (0)2477 220650 www.kogaudio.com

)

FOR- sleek design- clarity- 3D soundstage- bass punch

AGAINST- no balanced inputs- no headphone output

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and expected it. While retaining a sense of discipline, it still managed to provide a punch on drums and a rhythmic personality. Midrange and treble were left alone. For the latter, the Densen was noticeably fleet of foot, juggling the often complex arrangements of the prog rock track from King Crimson, ‘Three Of A Perfect Pair’, with an almost joyous lyricism. In terms of soundstage, the Densen didn’t have quite the same sense of maturity of placement as the more expensive Icons. What it did provide, however, was both air and space that allowed the mids and treble to breath easily, providing more room for the music to manoeuvre. In many ways, comparing the Densen to my reference system was unfair. After all, the B-175 was half the price of my own pre/power combo. The challenge for the Densen, however, was to see how close it could get to the reference sound. For example, on the ‘Chet Baker Sings’ jazz album, the Densen could easily match the reference’s 3D soundstage effect. The sense of depth and distance within the Densen soundstage was very impressive. This was further accentuated by the sense of space within the mix, a separation that very few, if any, integrated models can match. While the Baker vocal might not have had the same sense of intimacy produced by my reference, the Densen did perform admirably well for the price point while its emotional insight was second to none. Moving to the brass instruments, Baker's trumpet had tremendous focus via the Densen and was lithe, sprightly and precise. The grouping of these factors combined to produce toe-tapping musicality that forced my ear to forget that it was listening to a piece of hi-fi. Shifting to CD and spinning Skunk Anansie’s ‘Hedonism’, I

was impressed by the integrated’s punch and speed within the lower frequencies. The Densen had an immediacy and directness that demanded attention. Playing the Horace Silver track, ‘Cape Verdean Blues’, instrumental separation stood out, providing a catalyst for everything that was to follow. This meant that no information was lost due to clashing sonic elements. This performance continued through a series of compressed chart CDs. Despite the compression, the vocals sounded both clean and highly focused. The air and space of the amplifier helped to minimise the compressive elements, negating their aggressive nature. Not only was the strident midrange calmed but I now

had the ability to hear individual musicians, such was the Densen’s ability to reach into the mix to extract detail. This had a beneficial effect on complex vocal sequences. Harmonies sounded less like a chaotic mess and more like a jigsaw of interconnecting vocals.

CONCLUSIONImmensely effective in how it extracts and processes musical information, the Densen provided a clean and focused presentation with a penchant for solid bass, a delicate treble and a midrange that was both revealing and informative. The B-175 proves that integrated amplifier designs can compete at this price point.

The Densen B-175 produced 162 Watts into 8 Ohms and 272 Watts into 4 Ohms, a lot of power from a compact amplifier that ran only warm after a few minutes at full output. Like the B-110+ tested in our February issue the B-175 has a low damping factor of 17, identical to that of Naim amplifiers. This is still enough to exert good loudspeaker control but it is less than most transistor amps and may well flesh out bass a bit. Unlike the B-110+, which measured like a Class D amplifier, the Class AB B-175 maintained a steady transfer function, so under all drive and load conditions it produced second and third harmonic distortion in a consistent relationship to one another. A time domain residual showed clearly there were no crossover spikes; upper harmonics were absent - a good result. With distortion levels rising no higher than 0.15% under normal operating conditions (10kHz, 1 Watt, 4 Ohms) the B-175 is adequately linear and should sound clean and clear. Frequency response measured flat from 1Hz to 100kHz with no change imposed by volume control position or output load. Input sensitivity was low at 380mV, of consequence when external phono stages of low gain are used, then volume will have to be wound right up. The B-175 is powerful and

measured consistently well at all power levels so is a well developed design. NK

Power 162wattsCD/tuner/aux.Frequency response 1Hz-100kHzSeparation 89dBNoise -97dBDistortion 0.15%Sensitivity 380mVDamping factor 17

MEASURED PERFORMANCE

FREQUENCY RESPONSE

DISTORTION

All inputs are through phono sockets; there are no balanced XLR inputs. A main power switch sits above the IEC mains socket.

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