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SQF Son of Pharao Valve Amp

[Italian version]

Product: Son of Pharao Amplifier
Producer: SQF - Germany
Approx.cost: 9000 Euro
Author: Geoff Husband - TNT France
Reviewed/built: May, 2003

[SQF amp]


Regular readers will be aware that a while back I bought a pair of the Loth-x Polaris horn speakers that I had reviewed earlier. Read the review if you want to know why. At the time of that review and currently my amplification was/is provided by an Audion Premier 2 pre-amp and a pair of EL34 30watt Audion monoblocks. The combination worked beautifully together but it has to be said that the Polaris are rarely going to draw more than a watt from the amp and so the natural partner would seem to be a lower powered single ended valve amp. Obviously this gets my curiosity going and so late last year I reviewed the matching Loth-x Ji300b integrated, a gorgeous 8 watt SE amp running on 300b valves. However the result wasn't quite the match made in heaven that I'd expected - though the combination has the most incredible 'hear-through' midband it also emphasised the Polaris' lack of bass weight and peaky nature. Though there were moments to die for most of the time the Audion combo was much more listenable.

So the Loth-x Ji300b went back and I awaited the next contender.

Enter left, the SQF Son of Pharao (hereafter SOP), a 40 watt EL34 based integrated - not the perfect match in theory, but a very interesting design.


Valve amps by their very nature tend to be more attractive/dramatic looking than their solid-state brethren. The attraction of glowing valves seduces many, but look closer and many are rather prosaic steel boxes relying on the raw attraction of the valves themselves rather than any inherent quality of construction. The SOP does not belong to this category. The basis of the chassis is a massively heavy steel case with a machined aluminium frontplate extending in a sweep to draw the eye to the valves. One gets the impression that here a real effort has been to make the design look contemporary. Architectural is the word that springs to mind, the sort of architecture that gave us Gaudi's Barcelona Cathedral rather than the Greek architecture hinted at by the Ji300b. The design also (unlike the Ji300b) offers considerable protection to the valves (and your family). As well as the clever integration of the valves in this contemporary design there are beautiful touches like the two 'power meter' valves on either side of the amp which dance with blue flame in time with the music, though sadly with the Polaris the dancing was very gentle. Matching this blue was the digital display that shows all the amps selections and settings and is clearly visible from several meters away.

Fit and finish is as good as initial impressions suggest, important when shelling out this kind of money for an integrated amp. The volume control is beautifully weighted like the tuning knob of a class tuner, and the selector switch thumps to each position with finely oiled precision. It's 32 kgs of classy amp.

In a way its a shame for the SOP that it arrived just after the Ji300b, an amp that has simply amazing build quality that I cannot see anything improving on, but if the Ji300b is worth 100% the SOP gets a deserved 90%, few amps will match it.

Internal construction

I think I'm probably not treading on too many toes if I state that most valve amps are essentially rehashes of designs from the last 70 years. There's nothing inherently wrong with that, after all the best violins were made in Cremona 400 years ago, mainly because there were lots of violin makers there, just as in the 40's and 50's if you worked in audio you were a valve designer. But it is surprising that new original ideas are relatively rare in the valve world. SQF is an exception and makes full use of recent technology and blends it with traditional valves to make the SOP.

First the relatively traditional bit. The power amp section is comprised of 8 EL34's running in "galvanically coupled" mode (it says here), whilst the pre runs on 8 small signal valves in push-pull configuration. Now my Audions use 4 EL34's to produce 30 watts, the SOP has 8 EL34's ticking over at 40 watts, and the manual warns that peaks of 80 watts will be produced, this enough to drive most speakers in most rooms. Most amps of this power go for bigger power valves like KT88's but the EL34 has some fierce supporters in the valve world. It can be the sweetest valve around and produce a punchy bass, it's also dirt cheap, running from 15e and up.

So having dispensed with the simple stuff we start to see where the SOP departs from the norm, please forgive me doing this briefly but otherwise I'll never get to how it sounds.

Open up the SOP and unlike just about every valve amp it's stuffed with microchips. On start up the amp goes through a routine whereby it checks the state of each valve and alters its operating parameter (bias etc) and starts the valves gradually so as to reduce thermal stress and so extend their life.

Now to the control system. Here the heart is the volume control. This is a currently fashionable stepped-attenuator design. However most of these are based around a traditional knob which swings a 'wiper' around an array of resistors. The SOP is radically different. In this case the knob is a fly-by-wire device that has no physical connection with the attenuator. Instead here we find a ladder of resistors which are switched by microprocessor - no opening and closing of contacts, always a cause of losses especially over time. SQF claim this gives unique precision and channel balance. Though I can't verify this by measurement, channel balance with the Polaris was spot on which considering their efficiency is good, though as it should be. Personally I'm not a fan of stepped attenuators in my system, as the difference between positions is generally too big for fine adjustment when used with ultra high efficiency speakers. The Korato reference was practically unusable in my system and even the Ji300b was a little too keen to give me more watts than my Polaris needed for background listening. However the SOP was exemplary in this respect - the volume control is as fine as a traditional volume control but with all the advantages of a stepped-attenuator. Hats off to SQF.

The selector knob is also a fly-by-wire device and equally devoid of traditional opening and closing contacts, being microprocessor controlled. One turn to the right or left gets the next input (4 in all).

But we haven't even begun to explore the possibilities. By pushing a function butten then turning the selector knob (better to call it a jog-dial I suppose) you access a range of menus that can alter input sensitivity, balance and speaker damping factor FOR EACH INPUT! What that means is that once set you can switch from say Phono to CD and have the levels identical regardless of the output of the phono stage (there's no in-built stage) or CD player. Equally if there's any inbalance between channels with a particular source then that too can be corrected for that source and that source only. Changing inputs is done in a 'soft' manner - the amp mutes between positions then brings the next input gradually over a couple of seconds - it sounds a gimmick, but somehow I got to like it.

Lastly like a computer the amp can be set to power down after a certain period of time.

All of this trickery can be accessed directly using the big (and expensive) Phillips learning remote supplied. Now I don't like remotes and don't have a TV so really would have preferred a simpler remote, however for most people the ability to run their entire AV system from the SOP remote regardless of manufacturer will be an asset. And if I'm being honest I did find the remote volume a boon (though I never used anything else).

I hope SQF will forgive me for forgetting all the other clever things that this amp can do but I guess that after 1300 words I really ought to mention what it sounds like.

Sound Quality

I like my Audions a lot. They are the one item in my system that has stayed constant over the last four years, everything else has changed. So the system could be said to have been built around the amps characteristics, which inevitably biases any review towards amps with a similar sound (unless they are dramatically better in some other way).

Maybe it's the EL34's but despite the totally different appearance and high-technology the SOP just clicked right into the system. Even from cold it sounded sweet through the midband, punchy in the bass and clean in the treble. I'd had a hard time trying to like the Ji300b (I really WANTED to like it) but in the end I was glad when it went and let me get back to my Audions. Within 30 seconds I knew that in the SOP I had found an amp that would be a pleasure to have in the house.

So I set it so that it wouldn't shut off automatically and left it to burn in for a few days. Meantime I dug out the GramAmp Gold and Elevator step-up for phono stage duties, the most valve like transistor stage I've heard and it turned out a perfect match.

Back-to-back testing with amps is tricky with all the unplugging that has to go on but I persevered nevertheless. The result was interesting. The two amps, as already mentioned, shared a common presentation. My horns need a sweet amp to stop the peak in upper/mid output getting out of hand, and a warm, meaty presentation pays off too. Undeniably the SOP had one sure advantage over the Audion in that it was more powerful, for some people that alone combined with the amazing control interface would be enough to justify its (70%) higher price. In my case neither was a selling point. In my situation, given the high build quality, the only consideration was sound quality.

At first I thought the two amps so similar that it would be difficult to split them, but as so often happens the ability of the SOP took time to come to the fore.

First the bass. Both amps were warm and meaty, but the SOP sounded tighter and better defined, bass notes started and stopped with more aplomb. He result was that bass lines danced along. On Simply Red's "Sad 'ol Red" the bass sounded a bit harder edged, driving the rhythm section with more energy. Similarly The opening drum explosions in Nirvana's 'Nevermind' were high and fast in the mix with tremendous definition, the SOP fully exploiting the Polaris' dynamic capabilities to sound like a real drumkit. This track has tremendous soundstaging around the drums and here the SOP pushed back the walls 10-20% more than the Audions.

The climax of Verdi's Requiem has the most immense choir (at La Scala) with height and a sweep across the soundstage - once again the SOP made this bigger and better, you feel you can here more individual voices rather than a homogeneous whole.

This increase in vocal definition was noticeable on several albums which suddenly gained extra backing singers or multitrack effects. Roxy Music's first album (buy it) has a track "If there is Something" where the acoustic changes with alternate lines of the verse - an odd effect that I'd not really noticed before, the SOP laid it bare.

The sweet midband I've already mentioned - it's not quite as hear-through and revealing as the Ji300b, but personally I think with most recordings this can be too much of a good thing. It's also something that's easy to fake by rolling off the frequency extremes so the midband becomes prominent. The SOP avoids this trap remaining even handed across the frequency range. Female vocal, especially alto voice, is a tough test here, and the likes Of Chrissy Hind, Nina Simone and Tracy Chapmen made you want to reach out and thank them for the music.

And now for something completely different. I slapped on a rave from my past, X-Ray Specs "Bondage up Yours" with Polly Styrene's screeching vocal delivery (the female Johnny Rotten). This had so much energy I suddenly lost 25 years and had to pogo round the room. The volume was 'threshold of pain' but it was only when I switched it off and my ears were ringing that I realised just how loud I'd had that song. This is what high-end stuff can do, concert levels without you really knowing it. That this razor edged song retained all of its cut and slash yet remained under control speaks volumes for the complete chain of Orbe/SME4/Dynavector DRT-1s/Gold/Elevator/SOP/Polaris.

The Polaris (or my ears) don't really test the amps claim of being "Flat to 120 khz" but treble was certainly not lacking, as fine and refined as the Audion but just that little bit more extended. All frequencies showed the amp to be noticeably fleet of foot and all this combined to bring slightly better focus to the whole presentation.

Though I've mentioned it in passing I'll emphasis that the soundstaging was both deeper and wider than the Audions. Like them it was realistic, solid soundstaging rather than ethereal soundscapes, it also gave height information more readily.

To be honest I could sum this all up by saying this amp sounds just like my Audions but better in every single respect, and this in total makes it a painless and pretty major upgrade to them. I don't often write rave reviews but I guess this is one, but before I go to my final conclusion I'll list what I didn't like


One dislike - the name. Dunno why, just sounds a bit odd to me, I know it's supposed to be drawn from a much more expensive amp, the Pharao, but I think the amp needs no such link and it's name should let it stand alone.

This isn't so much a dislike list as a wish list. The amp has four inputs and no tape loop, there is an option with 8 + 2 loops and a sub output, but this inevitably adds to the cost. Personally I'd be happy to do with a remote with volume only and lose the rest - maybe that complex and expensive remote could be an option. The lack of a phono stage is just par for the course nowadays.

My last point is a worry rather than a criticism. Several years ago I visited David Chessell at Audion to have him service my amps. I asked him bluntly what would happen if he went bust and I needed a repair. Rather than take offence he simply said "any TV repair man could fix it". This is one of the big advantages of valve amps. They are essentially very simple items and are easily repaired (or even built) by competent electronics engineers. Some high-end valve amps use custom components, which you'd have to change to equivalents, but most are fixable. I suspect that the SOP needs SQF to survive in order to be properly serviced, even changing your own valves is discouraged. In adopting all the high-tech (and then some) of a high-end solid-state amp SQF have also exposed the amp to similar problems of long term servicing. Please don't get me wrong, I've absolutely no reason whatsoever to suggest that the SOP isn't every bit as reliable as any other amp, and the switchless relays should prove less prone to wear, but as with any high-tech equipment you better hope that if it does go pop they'll be someone there to help you out.


At a glance it would be easy to dismiss the SOP as a run-of-the-mill valve amp in a flash case and with a fancy control system. But then you pick it up - technology is light, quality transformers and cases are heavy - this is a very heavy amp.

I like it a lot. The unique control options will be a selling point for many, but I ignored them. Yet even stripped of its control electronics I still feel that it's sonic and drive capabilities alone justify its cost over my Audions. When the Pharao arrived I thought it would be OK, but not be the perfect match for my Polaris. After 2 months with the amp it's going to take a lot of willpower to put the damn thing back in its box and send it back - it will be missed, in fact I would probably buy it today if I could raise the cash. That my favourite turntable, the Clearlight Recovery, came from the same distributor (Innoplan) speaks volumes for their judgement.Certainly if it were my money it would get the vote over the Ji300b. Over the next few months I have several high-end valve amps coming on test, for any of them the Son of Pharao will be a tough act to follow.

systems used

© Copyright 2003 Geoff Husband - http://www.tnt-audio.com

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