[ Home | Staff & Contacts | HiFi Playground | Listening tests | DIY & Tweakings | Music & Books ]

Holfi Integra 88 SE - integrated amplifier

By demons be driven...

[Holfi Integra 88 SE]
[Italian version]

Product: Holfi Integra 88 SE - integrated amplifier
Manufacturer: Holfi - Bernic - Denmark
Approx. price: 3,300 $/Euro
Reviewer: Lucio Cadeddu - TNT Italy
Reviewed: January, 2003

This is the second time TNT-Audio deals with Holfi products, the first time being the listening test of their top of the line Xaurus Rex NFB CD player.
Following the main credo of this Company, the Integra 88 SE is a zero-feedback amplifier. Roughly speaking, for those of you less technically minded, this means there's NO comparison between the input and the output signal. More precisely, amplifiers with feedback compare their output with the input signal so to minimize overall distortion (sorry for the rough explaination).
When you see amplifiers with extremely low THD figures (0.0000x %) chances are they use large amounts of overall feedback. Many audiophiles believe feedback to be a harmful beast, when it comes to natural sound. As usual I will try to stay neutral and judge the results only. It doesn't matter how a result has been achieved, if it is fine to our ears.

Considering the other Holfi credo (battery-powered circuits) you may expect this Integra 88 SE to use batteries. Wrong! Battery-powered amplifiers are rare and normally HUGE and VERY EXPENSIVE (see certain Jeff Rowland gear, for example). Considering the 3300 Euro/$ price tag and the conventional size, there is no hope to find batteries inside the Integra 88 SE.
It has, instead, a very large power supply section, with a HUGE toroidal transformer (made by Noratel) and a quite good filtering capacity (100,000 uF via CapXon copper foil caps).
Knowning what Holfi did to their top of the line CD player, you'd expect to see electrically non-standard inputs. And yes, the CD input offers an unusual 800 ohm load (820 ohm, reading from the circuit board) which is ideal (or so they say) for their CD players.
A second line input, called PHONO, offers a 20 kohm load and so do the other line inputs. But! The PHONO input isn't a real phono one. No RIAA eq or phono preamp is available, indeed.
Considering the large power supply used inside the amp, the designers have preferred not to include a sensitive circuit like a phono preamp into the same cabinet.
This way they have avoided possible interferences of the large power supply with the phono circuits. They recommend using an external phono preamp instead (Holfi makes a few of these).
Anyway, it is strange - and somehow misleading - to see a pair of RCA inputs marked PHONO and a corresponding PHONO position on the input selector.
The PHONO and CD inputs are graced by luxurious horizontally-placed WBT RCA's while the remaining humbler line inputs (AUX, TAPE and TUNER) make use of gold plated basic vertically-placed terminals.

The Integra 88 SE is quite a powerful amplifier, with 125 watt RMS per channel on 8 ohm and 200 Watt per channel on 4 ohm. Peak output current is claimed to be 30 A on a 0.6 ohm load. Considering the Integra 88 is not recommended to drive loads below 2.5 ohm in order to avoid protections (of termic kind, I suppose) it is not clear how they measured the max output current on the diminutive 0.6 ohm load. Perhaps it is a theoric value or something measured without protections or via signal bursts.

[Holfi Integra 88 SE - inside view]

There's no doubt this amplifier is a lethal weapon, just have a look at the inside! The huge Noratel toroidal transformer is responsible for the weight unbalance at the left of the cabinet. There's no specification on its power but, considering its size, the fact the amp is claimed to have a max power consumption of 800 watts, I assume this transformer to be around 800 VA.
Everything is protected (unprotected? :-)) by a 6.3 ampere power fuse. The energy supplied by the transformer is hence stored by several CapXon caps. All this energy is needed to drive 4 (2 per channel) power output transistors. As they were completely hidden by the the heat sink and an aluminium plate, it has been impossible to understand which kind of devices have been used (and I didn't want to take apart the whole power section).
The rest of the amp is quite traditional and simple, with a single circuit board hosting everything, including a motorized ALPS volume pot (blue series) and the inputs selector, both connected to the knobs in the front panel via long steel shafts.
This has been done so to put the volume pot and the input selector closer to the inputs and hence minimize signal path.
Actually, everything in the layout seems to be done to make the signal path as short as possibile and, apart a few sets of cables here and there, the visual aspect of the inside of this amp appears neat and clean.
The speakers binding posts - nice and appropriately well-spaced - are connected to the power stage via longish solid copper bars (see pic). The unit is meant to stay permanently on so the on/off switch is placed in the rear panel near the IEC mains cable socket.
A switch in the front panel connects the outputs once the amp is ready to "go". 45 seconds later the amp has been turned ON a relais connects the outputs and the red led in the front panel switches from red to green. In stand-by mode the amp uses 15 watts of power.
The remote control allows just volume adjustment, NO inputs selector or ON/STAND BY is available.
The front panel, as standard on top of the line Holfi products, is of solid wood and so are the two large input and volume knobs. The rest of the unit is just a plain black metallic chassis.

These are the most relevant (claimed) tech specs:

As you can easily guess from the tech specs above this amp makes use of a very low feedback amount (possibly zero, as claimed). Why? Just have a look at the THD values, unusually high for a 100% solid state amplifier. As said, all things being equal, the lower the feedback the higher the THD (Total Harmonic Distortion).
Even the inputs sensitivity is quite unusual, as is the impedance load.

The MSR price of this amp puts it into the league of hi-end integrateds, meant for those audiophiles who have no room for a pre + power amp combo (or simply hate the idea) and prefer a all-in-one box solution without serious compromises, soundwise and power-wise.

The Holfi Integra 88 SE has been tested over a period of 6 months both with its natural partner, the Xaurus Rex NFB CD player, and other sources. It has been matched with 5 pairs of loudspeakers, each one being very different from the other in terms of quality, price and construction (bookshelf and floorstanding, 2 or 3 ways).

By demons be driven...

This Integra 88 SE is a very powerful amplifier. That's the very first thing you may notice after few minutes of serious listening. Its sound undoubtedly belongs to the best solid state tradition: energetic, fast, utterly dynamic and precise. Its tonal balance tends to be on the neutral side, just a tad bright from time to time. Its bass range is deep, powerful and extremely controlled. This amp doesn't sound soft or euphonic, it injects LIFE into every tune it plays.
This doesn't imply it sounds metallic or harsh! The keywords here are precision and control. Actually, it literally dominates the drivers, especially the woofers, either large and lazy ones or small and fast ones [Remark: there are even large and fast woofers as well as small and lazy woofers :-) That big woofers are slow is a classical - and wrong - audiophile legend. Roughly speaking, it all depends on the ratio between the generated magnetic field and the moving mass of the drivers].
If you have problems with your speakers sounding lazy and relentless, this amp may lend a (powerful) hand. In the bass region, it seems to prefer the lower octaves to the upper ones. As an example take the kick drum, you can FEEL the body of the instrument a bit more pronounced than the kick of the pedal on the drum. You can hear the propagation of the vibration till its deeper end but somehow the attack - tough still be extremely fast - appears a bit lighter than it should be.

More or less, the same can be said for the mid-bass region. Hence, instead of the sound of the fingers hitting the strings of the bass guitar (or acoustic double bass), you hear the whole body of the instrument. The difference is subtle, I'm not referring of day/night situations.
The mid and the mid-high range benefit from the extreme precision of this amplifier. This means that every nuance is reproduced with great care, be it in the leading theme of the track or hidden somewhere as a distant background noise. A bit monitor-like if you want, where monitor here does not mean in yer face sound. It simply means monitor, that ability to dig deep into the musical signal, allowing the listener to follow every pattern with ease.
Hence, as you may expect, voices are treated with a very special care, both soloists and choral singers, male or female. No virtual trace of harshness to speak of, just extreme precision in spades. Just sometimes, with lesser recordings, one may prefer a more forgiving attitude, so to make everything more bearable.
No exception with strings instruments (guitars, violins, cellos etc.): these benefit from a razor-sharp yet harmonically rich presentation.

The high range respects the dynamic and harmonic content of cymbals and other percussive instruments. With high pitched electronic sounds, the Holfi Integra 88 SE shows mucho control. It preserves the energetic content of these signals, without compressions of any kind. Hence, since many modern Music records are recorded too bright, one may find this amp a bit aggressive in the upper highs. The culprit may be found in its not-forgiving behaviour.

In few words I can say that this amp refuses any kind of euphony or softness but succeeds in sounding pleasant nevertheless. Tonally well balanced and harmonically rich, the sound appears coherent and consistent with every musical program.


As said, this is a very powerful and solid amp. Its dynamic resevoir is always full of fuel and allows to solve with authority every kind of musical variation. Even the laziest of loudspeakers may find a natural companion in this Integra 88: its no fear attitude makes the dynamic performance always sparkly and vivid.
At cost of being misunderstood, I'd add that the dynamic perfomance of this amp reminds me that of the best Krell power amps: fast, authoritative and energetic with virtually any speaker you can think of. If you are thinking your speakers are slow and tend to overshoot in the bass, plug in an amp like this and think again :-)
Pace, attack, decays and "damping" are excellent and leave no room to complaints of sort. Rythmic musical programs simply shine with this amp. You can play anything you want, from metal to hip hop, trip or industrial Music, always getting the right groove.
Then, if you wanna party :-) don't forget there's a volume pot that just asks to be turned clockwise, manually or via the remote: sit down and enjoy the fireworks or stand up and dance with your neighbourhoods :-)
Inefficient speakers? Here's the cure. Now the subtitle I've given to this review should be clear. "By Demons be driven" is one of the first tracks that came to my mind after listening to this amp. By demons be driven is a song from "Vulgar display of power", one of the most powerful albums by Pantera [1992 - Atco Records - 7567-91758-2].

Don't think it is a kind of demolition man, though. No way. It can slow down and admire the smallest variations in level with the most delicate chamber Music, if needed. Its sound is never boosted, it's just lively, punchy and always extremely correct.

Virtual image and soundstage

Thanks to its inner ability to sound precise and correct, it should not come as a surprise the pin-point imaging this amp is capable to create. The singers' and players' contours appear to be razor-sharp stable inside a virtual 3D scene that extends well behind your loudspeakers.
Getting back to that kick-drum example, I may add that while the position of the body of the instrument is clear, the precise point of the space where the kick hits the drum is more vague.
A quick comparison with a Naim preamp-power combo showed a much more precisely located attack.
Yeah I know these are typical audiophile paranoias but please do not forget we're talking of a 3,300 Euro/$ amplifier and so one has to investigate every nuance of its performance, even the silliest one :-)
Finally, a minor complaint relates to the airiness of the 3D scene. The extreme precision and rigueur of this amp, sometimes, leaves the listener wondering for more breath and air among instruments and singers.

Some advice

Holfi recommends leaving the amp permanently on. Moreover, they suggest to avoid listening to it before 2-3 hours of warm-up. I've found that after 30 minutes or so the amp was ready to sound at its best. Your mileage may vary so trust your ears only.
As many other hi-end amplifiers, this Integra 88 SE has no protection on the outputs. This means that if you need to change speaker cables you'd better turn off the amp or, at least, put it in stand-by mode.
Considering how peculiar the CD input is, it is strongly suggested to use a CD player which is DC or AC coupled with a 47 uF cap at least. Furthermore, the output stage of the CD player should be able to deliver quite large amount of current, in order to properly drive the CD input of the amplifier. Hence, the most natural choice is to use a Holfi CD player - for example the Xaurus Rex - as both have showed a preference one for the other :-)
More precisely, the Holfi Xaurus CD player sounded at its best when matched to the Integra amp.
Your choice of loudspeakers is limited only by their impedance, which shouldn't be any lower than 2.5 ohm. Low efficiency isn't a problem, considering the power this amp can deliver even on complex loads.
The mains cable is of the detachable kind, so upgrading via a better cord is strongly recommended.

Considering the wood finish of the front panel some extra care is needed. Wood is easier to scratch than aluminium.


Manufacturing and finish.
Outside, this amplifier is built like a tank: solid, massive and virtually undestructible. The position of the CD and PHONO inputs is simply perfect: no problems even with massive RCA connectors. Not so the other line inputs, equipped with cheap RCA females. On a 3,300 $/Euro integrated amp I expect to see only top quality stuff.
The speakers binding post are easy to use and - finally! - conveniently spaced.
Inside the amp things get a little bit worse, considering the set of "flying" cables here and there. The copper bars that lead the output signal to the speaker binding posts have no insulation, so quick oxidation may be a concern sooner or later.
The remote control looks damn cheap, especially nowadays, when solid aluminium remotes are standard equipment on amps costing less than one third of this Integra 88 SE. To make things even worse, it can only adjust volume. Anyway, despite the looks, it proved to be quite solid as several iterated Silvia-tests haven't been able to break it :-)

During use, I've had a problem with the life-saving device installed at home: it cut the mains supply three times when trying to power on the amp. This is not due to overload, as the device acts only when it measures potentially harmful currents in the system. I've not been able to understand the cause of this problem. Apart of this, the amp worked flawlessly.

Finally, let me spend a few words on the power-on delay. Almost a minute before connecting the outputs is very unusual, considering 3-4 seconds are the standard. For sure, those 45 seconds seemed an eternity to my 15 months daughter. When she asks for something (in this case, Music!) she can't understand why she has to wait almost a minute to listen to the Music, after the power on switch has been pressed. When this happened with the Holfi Integra, she looked at me like to ask "Daddy, have you turned it on or not? What are we waiting for?" :-)
Childish impatience aside, let me confess that I'm becoming more and more intolerant versus HiFi components that need long and complicated procedures before doing their damn job (playing Music). Even diesel engines do no longer need complicated and annoying warm-up procedures :-)
Leaving the units permanently on is NOT a solution. In my opinion, permanent power on is indeed a no-no. Considering the number of devices that stay permanently in stand by mode (tv set, CD players, cordless phones, answering machines, clocks, battery chargers etc.) the steady-state power consumption quickly approaches 100 watts or so. 100 watt x 10 hours is 1 kW, for 24 hours is 2.4 kW! Multiply this for 365 days a year and you get the picture! Apart from our wallets, we seriously damage the environment (more power consumed, more air pollution).

Let me conclude with two words on the price of this amplifier. While the sound it delivers can be considered good enough in relation with the cost (not so the Xaurus CD player) I'm a little bit perplexed when I think of where and how the 3,300 Euro/$ have been used.
After all, this is a quite traditional amp, with good components but nothing fancy enough to justify the cost. I've seen several competitors with components of the same quality level, sporting a much better layout and a decidedly lower price. Want some name? AM Audio, Norma, Pathos, Praecisa, just to name integrated amps we reviewed in the past with extremely good results. OK, these are Italian products and perhaps they cost much more abroad...but still...

Despite this amp hasn't conquered my heart (it rarely happens...) I have to say its sound is extremely good: it is precise, detailed, powerful and dynamic. Only, more pathos and a much more emotionally involving sound is needed to make my heart beat faster.
My personal feeling is that HiFi components that concentrate their performance on precision and rigueur sometimes lack emotion. Music is also (...mainly?) Emotion, not just metronomically reproduced sounds and tunes.


Exactly like its brother, the Xaurus NFB Rex CD player, this Integra 88 SE is a different HiFi component. As a stand-alone component, its unusual inputs can make partnering with other HiFi components a little more difficult than usual. This is not strange per se if you consider other well-known Companies use the same restrictive approach (think at Naim, for example). Hence, he who chooses Holfi embraces the whole Company philosophy and uses - possibly - components of the very same brand.
The price tag is steepish but justified by the overall sound quality of the unit. A personal, careful and extended personal audition is mandatory.

© Copyright 2003 Lucio Cadeddu - http://www.tnt-audio.com

Manufacturer's comment

Dear Lucio,
I think you have captured the very essense of the Integra 88. I also get that the effort you put into making a review is much bigger than what I'm used to from reviewers. Big acknowledgement for that!

The Integra 88 was made to kick even difficult speakers alive, not surrendering a harmonic and musical product. According to your review we have succeeded in doing just that.
Specific comments: the warning about impedances below 2.5 ohms should be understood as a general load. Speakers with a dip to low impedances at some frequencies (e.g. Electrostatics) is not a problem at all. Actually the warning is only meant as a heat protection warning to ensure long and trouble free lifetime for the amplifier (not to dry out capacitors because of high temperature). The amplifier works fine even into very low impedance, though playing loud for a long time into a load like that will cause the amplifier to get pretty hot!

Being very through with your review has a backside to it, as the successor to the Integra 88 is on the market now - Integra 5.1. It produces similar sound quality regarded as a 2-channel amp only (I prefer the 5.1 to the 88 myself as being cleaner and more musical but the 88 is more powerful). It is (a little) cheaper than the 88 and it has three more channels (5 x 100W) to play DVDA/SACD.

We would like to capture your heart, so maybe you would like to do a review of the Power NB1, fully battery powered 70 kilos, 2 x 130 W??
Does it cost money? Yes! However the cheapest alternative is the Rowlands at 5 times the price.
Peter Holstein - Holfi

[ Home | Staff & Contacts | HiFi Playground | Listening tests | DIY & Tweakings | Music & Books ]