hi-fi world - Usher Audio

REVIEW 

Heavy Metal 

Weighing in at a serious 40kg, Usher’s R1.5 is a 

pure Class A power amplifier with a difference 

- especially when you consider its extremely keen 

pricing. Stewart Wennen reports… 

HI-FI WORLD 

This magazine makes no 

secret of its love for 

pure Class A operation; 

there’s no doubt it brings 

something to the party 

that conventional Class 

AB amplifiers cannot. The lack of 

switching distortion makes for an 

unusually clean and open sound - or 

to be more precise, the switching 

distortion of Class AB biased designs 

pollutes and sullies the original sound 

(which is, of course, naturally clean 

and open). 

Trouble is, the trade-off with 

Class A is that power output comes 

right down – and to get it up to 

Class AB levels the amplifier needs 

to be seriously beefed up to dissipate 

the tremendous heat generated by 

those output transistors running at 

full tilt. Of course, this makes things 

very expensive, with the result 

that almost all Class A amplifiers 

command a price premium. Those 

that don’t, such as the lovely Sugden 

A21a (see p16), simply don’t have 

much power. 

Well, Usher seems to be trying 

HI-FI WORLD NOVEMBER 2005 www.hi-fiworld.co.uk 

to square the circle, so to speak, with 

its Chinese built high end stereo 

power amplifier, offering a claimed 

125W RMS per channel (and 40kg’s 

worth of heatsinking to cope with it 

all) for a more £1,500. Too good to 

be true 

It’s an understatement to say 

this is a visually imposing product, 

the 480x480x225mm R1.5 being 

instantly recognisable due to its vast, 

chunky brushed aluminium fascia 

panel, with its huge contoured grab 

handles and large rocker switch 

with power indication via a blue 

light emitting diode. Truly massive 

heatsinks stretch down both sides 

of the unit. Inside, the power supply 

smoothing capacitors are configured 

as two pairs of 10,000-microfarad 

units. The output stage uses multiple 

pairs of Motorola MJ15024/025 

heavy-duty output transistors. With 

a massive thermal capacity, this unit 

utilises a thermal trip which switches 

the amplifier off in case of a fault 

condition. The amplifier also has a 

soft start circuit to allow the current 

surge to be better regulated on 

power up. Surprisingly perhaps, there 

is no loudspeaker protection on this 

model. 

Fit and finish, as with all Usher 

products, is rather good. At the 

rear, there are two pairs of the 

best binding posts I have ever seen. 

They allow for the use of 4mm 

loudspeaker terminations whilst 

at the same time the use of heavy 

spade terminals. These binding 

posts lock the 4mm plugs into the 

post thus negating the possibility of 

accidentally pulling the cables out of 

the sockets. Signal input termination 

is taken care of with a pair of high 

quality phono sockets and also a pair 

of XLR balanced inputs, although 

balanced operation is a £100 option. 

Mains electrical power is supplied via 

an IEC socket. 

SOUND QUALITY 

The Usher R1.5 got off to a 

promising start with BBC Radio 

Four on FM, where voices sounded 

unusually delicate yet weighty. Indeed, 

its midband instantly impressed with 

a full, rich tone. Moving to vinyl, and 

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REFERENCE SYSTEM: 

Origin Live Aurora Gold/ Conqueror/ Sumiko Blackbird 

Acoustic Solid Small Royal/ Hadcock GH242 cryo/ Music Maker Three 

Graham Slee Jazz Club phonostage 

Custom built passive preamplifier 

ATC SC35M loudspeakers 

James Brown presented a beautifully 

wide and deep stereo image, with 

stage depth to die for and correct 

placement of the musicians. Again, 

the bass proved satisfyingly vivid. 

An early 1960s John Williams mono 

flamenco guitar recording done at 

Abbey Road, with its legendary warm 

sound, didn’t disappoint either. The 

Usher successfully captured the 

warm rich sound of the instruments 

and correctly transcribed the 

decay of the notes in the studio. 

All these audio clues issued forth 

in abundance, to make the listening 

experience all the more profound. 

Moving to some old school rock 

and roll in the shape of Led Zeppelin 

(‘2’), and the hard driving rhythm 

machine filled my listening room 

with huge bass transients, the kick 

drum accenting the structure of the 

music. The Usher certainly takes no 

prisoners; I have been listening to 

Led Zep for many 

years and have 

seen them quite a 

few times in their 

heyday, but I have 

never heard them 

come with so 

much verve and 

drive before in my 

own front room. 

The space around 

the musicians 

was ‘inky black’. 

Some classic 

reggae from 

UB40 (‘Present 

Arms’) once again 

came over with a 

vast soundstage, 

the musicians 

seemingly laid 

out in an arc. 

Background noise 

so low that there 

was an almost 

ethereal feel. 

With lightning 

transients, the 

Usher proved a joy to listen to. 

A change of pace was due, so 

the next disc on the turntable was 

from Beethoven. As the string section 

murmured the introduction to his 

"this is affordable Class A without tears…" 

Piano Symphony No. 3, I was able 

to fully appreciate the delicacy and 

sheer power of the music played 

by a great orchestra. This Deutsche 

Gramophone recording has been 

lauded as possibly the 

finest transcription 

ever made of this piece, 

and I could see why. 

Likewise, solo female 

vocals from Carol 

Kidd (Linn Records) 

sounded almost magical, 

the Usher’s ability to 

transport the listener 

to the room where the 

performance is taking 

place proving uncanny. 

REVIEW 

DP SAYS: 

CONCLUSION 

This was an interesting one. Costing £500 more than 

An extremely impressive bit of kit, by 

Sugden’s A21a but offering some 105W RMS per side 

any standards, the Usher R1.5 makes 

extra, plus amazing (perceived) build and Krell-like styl- 

an excellent ‘do-it-all’ high end power 

ing, the Usher R1.5 would seem to be too good to be 

amp. From a consumer’s point of 

true, so I’d expected to be disappointed upon audition. 

view it’s affordable Class A without 

Well, I don’t think it’s as good as the A21a in some 

tears, as you get none of the speaker 

respects; it lacks the Sugden’s liquid, effortless, flow- 

matching issues that the Sugden A21a 

ing musicality. This isn’t in itself a criticism, as so does 

presents (due to its understandable 

virtually every other amplifier I’ve heard too. However, 

lack of power). This behemoth will 

the other side of the coin is that it boasts massive 

drive pretty much anything without 

reserves of power (by Class A standards), real depth 

so much as batting an eyelid; which is 

and space and a sense of tidiness and proportion that 

impressive 

the Sugden lacks. This makes for a brilliant package; 

no matter what you play through the Usher, it comes 

out in a tremendously authoritative way, with superb 

fine detail, excellent texturality and an excellent 

resolution of the recorded acoustic. Even if it came 

packaged in a biscuit tin, to do this for £1,500 would 

be major feat – so it’s outstanding considering how 

well the amplifier is built. In absolute terms, the R1.5 

lacks the liquid musicality of some rival amps (Musical 

Fidelity’s A5cr is a case in point), or the finesse or 

Lyngdorf’s SDA2175 (another outstanding product, and 

this at under £800), but it’s still right up there in value 

for money terms. For many, myself included I dare say, 

the fact that it looks like an £8,000 Krell might just seal 

the deal. 

The Usher has vast thermal capacity, 

with huge heatsinks and a massive 

thermal sink under the multiple output 

devices. It produces 150W into 8ohms 

and 200W into 4ohms – not enormous 

by today’s standards – so the amp is 

sized to run flat out for long periods I 

presume, without thermal protection 

kicking in. 

Distortion levels were low into 

an 8ohm load, just 0.003% second 

harmonic showing in the midband. 

However, at higher frequencies this 

rose to 0.02%. Into 4ohms however, 

there was quite a marked increase in 

distortion, second and third harmonics 

appearing in equal quantity. Level 

measured around 0.03%, rising to 0.1% 

toward full output at high frequencies. 

This is still a good performance, but 

the substantial change in distortion 

pattern at higher currents is a concern. 

Input sensitivity was low at 1.5V; 

the Usher needs a preamp with x5 gain 

or more if it is to match old 300mV 

tuners, cassette decks and such like. 

Frequency response was normal 

enough at 4Hz-42kHz (-1dB). 

VERDICT 

MEASURED PERFORMANCE 

) 

£ 

Excellent sonics allied to serious power 

output makes this an outstanding midprice 

product. 

USHER R1.5 £1,500 

HiAudio 

+44 (0)1443 231458/9 

www.hiadio.co.uk 

The Usher Reference 1.5 is rather 

large for domestic use, considering 

its power output. It looks better 

suited to arduous professional use. 

Measured performance was good, if not 

exceptional. NK 

Power 

150watts 

Frequency response 4Hz-42kHz 

Separation 

88dB 

Noise (IEC A) 

-116dB 

Distortion 0.02% 

Sensitivity 1.5V 

0.1 

level 

(%) 

0.05 

HI-FI WORLD 

Distortion 

0 

10k frequency (Hz) 

60k 

www.hi-fiworld.co.uk NOVEMBER 2005 HI-FI WORLD 

P34-P35 subbed$.indd 35 30/4/07 11:28:59

hi-fi world - Usher Audio

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