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Issue 44£4.50

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R E P R O D U C I N G T H E R E C O R D E D A R T S

8/44

LET ‘EM ROLL

Loudspeakers that dare to be differentValve amps and a bit of solid-stateAnalogue and Digital source components

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EQUIPMENT REVIEW

performance. Trouble is, music is not steady-state and predictable!While negative feedback can be used to make a poor amplifier lookgood on paper, it definitely won’tcreate an amp that sounds as good

as it measures.

The Prologue 3pre-amp also runs withoutnegative feedback, and does not havethe usual Cathode Follower outputs –it’s Anode out. It also features tuberectifiers, rather than solid state ones. While the difference on paperbetween the integrated Prologue 2and the separate pre/power Prologue3 and 5 is quite small, the net resultsonically seems to be a noticeablybigger and more holographic musical

presentation, with increased depthand spaciousness.

Like the Prologue 2, the Prologue3 and 5 produce an exceptionally rich tonality. The bottom end is fulland weighty, with an unusually richmid-band and smooth sweet treble.The presentation is distinctly warmand honeyed – the classic way a tube

amp is supposed to sound,but all too rarely does. This may take a littlegetting used to –especially if you’re more

accustomed to listening to tight well-damped

transistor amplifiers – thesonic equivalent of movingfrom Canada to Florida!Once you do get used to it,there’s little doubt as towhich sounds more realand true-to-life. At least

that’s my take on it. You get more of that weighty

woody warmth and bloomon instruments like acoustic

double bass, and the result is very believable. There’s somethingvery inviting and beguiling about thisamplifier. It’s so smooth and refined.Note the beautifully sweet top-endand deliciously liquid mid-range –absolutely gorgeous. In short,extremely clean and effortless, yet not without point or incident.

For all its warmth and refinement,the musical presentation is

The Prima Luna Prologue 3 Pre-amp andPrologue 5 Power Amp

by Jimmy Hughes

It was back in Issue 35 that I reviewedthe Prima Luna Prologue 2 integratedvalve amplifier. And very good it wastoo. I loved its warm lush sound andsmooth mellow richness. Sonically, itwas unmistakeably ‘tube’ in the bestsense of the word, with all that implies.Not only was it an excellent amplifierin terms of sound quality, build, andfinish, it was reasonably priced andvery good value. I really liked it, andwas sad to see it go.

The Prologue 3 pre-amp andPrologue 5 power amp represent the next stage on, so to speak,and (without thinking) I just assumed a two-boxversion would be morepowerful. In actual fact, the difference in specification is not so great. Bothmodels offer around40W per channel, andmore or less similar band-width and distortion figures. The difference is a new Driver andPhase-Splitter circuit, which allowsthe Prologue 5 to operate withoutglobal negative feedback.

Most amplifiers have a degree of negative feedback to help reducedistortion. The idea is to feed back a part of the signal so that additivedistortions are cancelled out. It works superbly well on steady-statepredictable signals (like test tones),and greatly improves measured

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actually quite vivid and dynamic, withexcellent attack andimmediacy. As the Prologue2 was no long around, Icouldn’t directly compare itto the Prologue 3 and 5combination. But mysense is that the two-boxamps sound noticeablymore three-dimensionaland holographic. There’sa much greater depth andrange to the sound, with increased width andspaciousness.

Now 40W is not an especially highoutput. But don’t pre-judge thePrologue 5; it actually sounds verygutsy and powerful – as though it hada couple of hundred Watts in reserveand was just idling along. My ImpulseH-1 horns are fairly efficient, but byno means exceptionally so. Yet thePrologue 5 had power in reserve todrive them as hard as I would everwant – or so it seemed. There was thatsense of ease and effortlessness oneassociates with big amplifiers.

And, because the musicalpresentation had such holographicdimensional qualities, voices andinstruments were projected into theroom with a tangibility that didn’trely on muscle alone tocreate a big room-filling effect. Thesound was big andfull-bodied. Even whenplayed quietly themusic had acommanding presenceand energy. Clarity wasexcellent, and so too was pitchdefinition. Even during complexpieces, the Prologue 3 and 5 retainedpoise and control.

Although there’s no more poweravailable, the two-box amp definitelysounds as though it has more inreserve than the Prologue 2. As wellas appearing subjectively morepowerful, the Prologue 3 and 5 also

sounds more delicate – more finelynuanced - with a lovely honeyedrichness that’s very attractive. You canhear these qualities on pretty much alltypes of music.

Of course classical music andnaturally-recorded acoustic jazz areperfectly

served.But so too arerecordings ofelectronically-createdsounds and aggressive brightly-recorded pop albums. With the latter,there’s no lack of brilliance or bite,but at the same time the amplifier - by

not adding its own edge andaggressiveness – helps create animpression of refinement and control.

The Prologue 3 and 5 sound verycivilised without being boring or

bland. The top-end is very wellintegrated with the mid-band, meaning that sourceshave to be really rough and

abrasive to provokeharshness. Yet there’s nosense of things beingartificially smoothed-over or prettied up.Indeed, the opposite is

true – the sound isunusually vibrant and colourful, withvivid detail and brilliant clarity.

Timing is excellent, and there’sgood rhythmic drive and forwardmomentum. I liked the way thePrologue 3 and 5 gave you ‘time’ -time to listen and assimilate themusic. I’m not sure you’d call this afast amplifier; the full bottom endmakes sure that bass lines are

properly weighty sothey really under-pinthe music, as theyshould. This in turncan give theimpression of thingshappening withgreater poise anddeliberation. The ‘speed’ of anamplifier is a

contentious issueanyway, since no one has

ever related measurablethings like transient rise time

with the subjective impression ofthe music moving quickly. In my

experience, the absence of bass is themain thing that creates a (false)impression of speed. Put another way,the Prologue 3 and 5 do not create awelter of fast but unrelated leadingedges that can sound superficiallyimpressive, but soon tires the ear.Presentation is always coherent andintegrated.

EQUIPMENT REVIEW

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The power amp offers a choice of 4 Ohm and 8 Ohm outputs so youcan achieve a good match with yourloudspeakers. The correct matchgives the highest output, but I selected the 4 Ohm optionbecause (with my speakers)this gave a slightly ‘darker’richer tonality, with bettercontrol. You lose a small amount of poweras a result, but this isnot serious. Try bothyourself beforedeciding.

Like the other Prima Lunaamplifiers, the Prologue 3 and 5feature something called Soft Start,which reduces stress to the tubeswhen the amp is first switched on.The circuits do not run to the tubes to the edge, meaning longer tube life and less deterioration over longperiods of use. When the time comes to replace thetubes,

there’s no problem with biasing thanks to something called Adaptive Auto Biasing, whichindividually monitors each tube andmakes the necessary adjustments.

Prima Luna claim the Prologue 3and 5 are unusually quiet in terms of residual noise, and this seems to be the case. While I could just detecta little hum and buzz with my earclose to the speakers when testing the Prologue 2, I could hear nothingwith the Prologue 3 and 5. It seems

to be pin-drop silent – or there-abouts! Problems with residual

noise can be an issue forthose with abnormallyefficient speakers likeLowthers. But on this

showing the Prologue 3and 5 will pass

even this stiff test. Good, afford-

able tubeamps are

becomingsomething

of a Chinesespeciality. This is one I

could certainly see out the rest of my days with. It’s a gorgeous

amplifier that sooths, charms andbeguiles, while stimulating the senses.What’s more important, its qualitiesgrow on you; the more you hear it, the more you like it. There’s never anysense of the amp drawing attention to itself and away from the music.

EQUIPMENT REVIEW

Prologue 3 Pre-amp

Type: Valve rectified,

vacuum tube line-stage

Valve Complement: 2x 12AX7

2x 12AU7

2x 5AR4

Inputs: 4 x single-ended line-level

Input Sensitivity: 200mV

Outputs: 2 x single-ended line-level

1 x single-ended tape out

Output Impedance: 3.5KOhm

Overall Gain: 11.5dB

Dimensions (WxHxD): 280 x 190 x 395mm

Weight: 10.6Kg

Finishes: Black, Silver, Champagne

Price: £1099

Prologue 5 Power Amp

Type: Push-pull, zero-feedback

vacuum tube power amp

Valve Complement: 2x 12AX7

2x 12AU7

4x KT88

Input Sensitivity: 810mV

Input Impedance: 100 KOhms

Power Output: 40 Watts/8 Ohms

Dimensions (WxHxD): 280 x 190 x 395mm

Finishes: Black, Silver, Champagne

Price: £1099

UK Distributor:

Absolute Sounds

Tel. (44)(0)20 8971 3909

Net. www.absolutesounds.com

TECHNICAL SPECIF ICATIONS

The result is natural and real-sounding, yet friendly and

relaxing. It may not be as big a bargain as theintegrated, but it more than justifies the difference

in cost. If you thought the Prologue 2 wasgood, wait until youhear these…

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