Keilwerth SX90R tenor saxophone
Origin: West Germany
Guide price: £2000+
Age of review model: Various
Date reviewed : Feb.02 ( Addendums added, see below )

Description: A professional level instrument, brass body and keys, nickel plated body with gold lacquer overlay. Features 'rolled' tone holes.

I have to say that this review may worry quite a few SX90R owners - so I would welcome comments from other repairers/owners to incorporate into this review.

The first thing that meets the eye with this horn is its finish. Keilwerth have chosen an unorthodox approach by giving the body a coat of nickel plate, and then following it up with a coat of gold lacquer ( Example pictured is a standard lacquered brass model ).Undoubtedly durable, nickel plate being extremely tough - though lacquer will be lacquer, and may not be as durable.
However I'm not so sure the marriage is a happy one, I found the finish to be slightly streaky with distinctly darker patches around the fittings.
Another finishing defect was file/machining marks on some of the keys.

An examination of the instrument revealed a far more serious defect.
Keilwerth market this sax as having tone hole rings. Although this gives the horn the appearance of having rolled tone holes, true rolled holes have the lip of the hole rolled over and tucked underneath to form a beaded rim to the tone hole - a practice common with American horns of the 40's and 50's. Advantages include extra strength to the tone hole and a wider seating area for the pad. Disadvantages are that it's extremely difficult to level such holes in the event of damage, and there is some justification to the point that a less well defined tone hole rim makes for a less definite seal.
Keilwerth have compromised - the 'rolled' section is actually a separate fitting, soldered onto the tone hole. This means it is possible to remove and replace the rolled section, giving some of the advantages of a true rolled hole and fewer of the disadvantages.

All good and well, but an examination of the instrument showed that the tone holes from low D down were slightly warped.

Now, this is not an uncommon problem - with cheaper horns, and is easily remedied with a light dressing of the tone hole ( more severe warps require bringing up from beneath the tone hole ). However, these horns typically have straight tone holes - the addition of a roll complicates matters enormously. Dressing a rolled tone hole runs the risk of breaking through the roll, and even if this doesn't happen it leaves an uneven surface area on the top of the tone hole.
On a professional level horn such an error is a grave manufacturing defect - and a remarkable oversight given that Keilwerth fitted the rolls separately.

Such errors can be compensated for by backing up the pads to match the profile of the tone hole - but this is an expensive and skilled procedure and is never as reliable as a true tone hole and a correspondingly flat cup.

I noted too some roughness around the inner rim of the tone holes, indicating poor finishing.

Perhaps the horn had been damaged? I looked, but saw no evidence of any stress to the body - and whilst it's common enough for the low C guard to take a knock and warp the tone hole I am certain that the run of warped holes from D down is a manufacturing defect, as such damage would be quite visible.

The design of the keywork and fittings is nice, Keilwerth have chosen a more angular design for the pillars, which lends the instrument a nice 'clean' feel.
The addition of a brace arm extending from the low F up to the Aux.F key above it is a welcome addition, providing a more secure closing action to the right hand key stack... something that's often a problem on tenors, particularly when the action starts to wear.
An unusual addition is a lever that extends from the G# actuating arm, across the G# key cup and onto the Aux.F key cup. I was somewhat confused as to the function of this key, but after having seen a number of Keilwerths I've finally sussed it out.
It's supposed to be a mechanism that prevents the G# key cup from sticking. How it does this is rather nifty.
In normal use, and with a working G#, the arm does nothing at all - but should the G# stick, the lever pivots on the stuck G# key cup and makes contact with the Aux.F key cup. Once it does this it tries to force the Aux.F key down - in effect using the spring of that key to boost that on the G# key cup and supplying the upward force at the pivot of the lever.
It works, but in spite of setting the lever up correctly I found there was a slight delay before the G# cup came unstuck.
Still, a 'late' G# will be better than no G# at all - although most horn players will habitually test the G# and low C# keys before playing. If a stuck key is found it's a simple matter to just lift it off with your finger, and thereafter it shouldn't trouble you again for the duration of your gig/practice. If it does then it's rather more likely to be an imbalance of springing.
( Since writing this review I've noticed a number of SX90R owners commenting on sticking pads - this will be due to the extra surface area on the tone hole rings - see the article on sticking pads for a solution ).

I noticed too that the pearls were extremely thick. I felt this made the action appear higher than it actually was, but this is just a personal preference. Having said that, I found the action of the roll-on Bis Bb to be remarkably comfortable.

Whilst I'm on the subject of key pearls, I found a problem with the low/mid Eb. In fast passages it was possible to get my finger trapped between the Eb touchpiece and the underside of the D finger button. It didn't happen every time, but often enough to make me acutely aware of it.
I can see what's happening - if you're playing a jump from, say, E to Eb you instinctively press the D and the Eb key at the same time. If the Eb key is ever so slightly ahead of the D key it's possible to trap the tip of the little finger between the two.
Naturally, not every player will be affected by this - and even then it's perhaps something that you'd learn to avoid - but in comparing the D key with a Yamaha 62 tenor it can be seen that the Keilwerth's finger button is a great deal closer to the bottom of the cup, and thus very close to the Eb touchpiece when it's pressed down.

The palm keys are of an interesting design! The bane of sax players has always been the relative height of the palm key touchpieces, leading to all manner of gadgets and additions to raise the keys to a level comfortable for the individual. Keilwerth have recognised this dilemma and have incorporated an adjustment into the palm key touchpieces. Whilst I applaud this innovation I have to say that I thought the design to be somewhat less than elegant, which is a shame as this is a rather elegant horn otherwise. Also, I felt that the touchpiece supports were a tad on the thin side...maybe 4mm in diameter? These keys get a lot of stick in use, it'll be interesting to see how they hold up.

The setup on the horn was a bit suspect...most of the right and left hand stack key pads were up at the back, giving a spongy feel to the action and leaving a leak at the front of the pad. The use of a cork buffer on the Bis Bb arm imparted a squeak to the action. It must be borne in mind that the sax had had a year's worth of use though.
After a setup the action improved enormously. Not quite the precision feel of the Japanese saxes, and not quite the fluidity of the Selmers...but a nice middle ground with a responsive and fast feel.
The bell key cluster is very well designed. Sturdy yet smooth, one of the best designs I've seen.

Tonewise...well, it's a very individual thing. For me I felt the horn lacked 'zing'. There's a certain 'crackle' to the tone that I listen out for, one that inspires me to keep on playing - I didn't find it, though I did find a nice evenness of tone over the entire range. My testbed Vandoren T25 gives a neutral to slightly bright sound, and I would have expected to hear a little more edge in the tone. I felt it leaned more to the classic Selmer or Conn sound than to the Yamaha sound - but of course, you may well think differently!

Last impressions. Certainly an interesting horn, with some very nice touches - but so badly let down by some serious manufacturing defects and an iffy finish.
I'd want more for my money, and I'd strongly advise potential buyers to take a packet of cigarette papers with them when they try the horn - and check those lower tone holes!

Additional notes:

Since this review was published, I have received much correspondence and seen many comments about it dotted around the web. I think it's worth reviewing those points here - if only to save me having to re-write them time and again.

Surely no manufacturer would consistently turn out horns with a defect - perhaps you're only seeing the worst examples?

It seems very unlikely that only the worst horns turn up at the workshop. Indeed, the people who respond to my offer of a free check-up often have no idea as to whether their horn is affected by the problem.
I've seen anomalies on horns by other manufacturers, and where serious have advised clients to return the horn for replacement. Once you get to the standard of the basic Yamaha horn, serious structural or cosmetic defects are gratifyingly rare - and can be counted on the fingers of one hand in as many years. The problem with the SX90R horns has turned up on every* example ( fourteen, and still counting ) thus far. How many do you think I need to see before it becomes obvious that something's not quite right?
I've seen reports of other examples from third parties, but in the interests of accuracy I can really only comment on the horns I've seen personally.

* I'm happy to report that I have now seen one example with level tone holes, as noted in the addendum below ( 04/11/05 ).

If people don't realise their horn has a problem, surely it's not that serious?

It's what you're used to. Any repairer will have worked on horns that have only come in for 'a bit of cork', and found leaks on the bell keys. Having repaired those leaks and handed the horn back, the client will often remark that they never realised they were missing so much 'oomph' down the bottom end.
You compensate, and you become accustomed to it - but that doesn't make it right or desirable.

I tried a number of horns out in the store - the Keilwerth beat them hands down.

And so it might do - it is, potentially, a very nice horn. But it comes back to what you're used to - and when trying out new horns you'll be taking on board a whole package of new impressions and sensations, and you may not realise that the horn is capable of more than you're getting.
Bear in mind too that the problem represents 'trouble in store'. New ( and therefore soft ) pads have a degree of accommodation in them - once they start to harden up they'll be less and less able to compensate for any anomalies in the tone holes. This could very well take a few years, but it would be a repetitive cycle. You'll be seeing a lot more of your repairer than owners of other makes of horn..
Keep in mind too that very few stores bother to set their horns up - so you could well be comparing one leaky horn with another leaky horn.

Hey, I'm happy with my Keilwerth!

I'm really pleased to hear that - and I hope it remains to be the case.
Assuming a given quality of manufacture I can repair a horn, hand it back to the client, slap my hand down on the workbench and promise, even guarantee, that they'll be happy with it for a long time to come. I can't do that with the SX90R.

I know a guy who says he's never come across this problem, nor have any of the people he knows who have these horns.

Good for him - I'm delighted to hear it, but that makes him and his friends the luckiest people on the planet.
Consider the statistics. There have to be tens of thousands of these horns out in the marketplace, so the chances of coming across a single anomaly should be reasonable enough. The chances of coming across that anomaly twice should be quite rare. Three times, even rarer still.
Once you get to four times, five times, six times etc. - the probability factor is getting seriously phenomenal. Now consider the probability of seeing those anomalies on consecutive horns...one after another, from a random selection out of thousands and thousands of horns.
Am I really so fantastically unlucky that I've only seen the dregs - or is this a consistent and repetitive problem?

And some people seem to take criticism of their horns rather personally. I've seen comments ranging from complete dismissal of the problem through to suggestions that even if there is a problem it really doesn't matter! In one instance I saw a claim that all the horns I'd seen had been mysteriously damaged in transit ( that one made me chuckle ).
Don't be satisfied with glib brush-offs...ask the same questions I've asked, read the accompanying article on warped tone holes and weigh up the pros and cons for yourself with the benefit of factual information and unequivocal proof.

My repairer has never heard of you, and I'm told that none of the UK shops know you.

Does that make a difference?
Anyone can be shown how to diagnose a warped tone hole, you don't need to be an engineer or a professional musician to see the problem or to understand it.
In any event I value my independence and take great care to ensure that personal or business relationships don't compromise it, no matter how illustrious the name ( the article on Ultra-Cheap horns clearly shows how that works in practice ).
I can see how a retailer with a stockroom full of SX90R's would want to distance themselves from any hint of a problem - and if someone expresses an opposing view you'd be well within your rights to ask what their associations or interests might be.

I can get my low notes - surely my horn doesn't have this problem?

Just about any horn is capable of belting out the low notes. If there are minor leaks you can compensate with extra finger pressure and more air support. The real test is in playing subtone ( that lovely, soft, typically Getz sound ), and with light finger pressure.
If you pick up a well maintained and regulated horn and blow subtones around the bell notes, you should be able to do so with ease - and with a very light touch. If you find you have problems you tend to compensate subconsciously - in the same way that you will adjust your embouchure to play in tune.
What this particular problem does is not necessarily stop the horn dead in its tracks, rather it takes away a percentage of the tone and volume ( I reckon about 20% ? ), which only comes back if you tighten your grip on the keys. For many players this would be enough to send them scurrying off to their local repairer. It's a fault, no two ways about it.

How do I know you're being entirely honest?

Mainly because you're reading this article. This isn't a secret document, hidden away from prying eyes - it's a public statement, subject to public scrutiny...and legal scrutiny.
There's one beneficiary from the time and effort that goes into these review pages - and it's you.
On these pages you'll find plaudits and put-downs in equal measure. I hold no allegiance, I simply report on the evidence before my eyes without fear or favour. And I can do that because I have the evidence. None of the horns reviewed are figments of my imagination, they exist, they have been made, bought and paid for - warts and all.

You seem rather over-concerned with this issue.

Keilwerth's tag-line is "Saxophones are our passion".
Guess what? Same here! I reckon any of my clients would be able to attest to how much these amazing instruments thrill me. You can see it for yourself - just pop along with a vintage beauty in mint condition, or a unusual horn with an interesting history and you'll see my eyes light up like a kid who's been given the day off school and then found a fiver on the ground - right outside a sweetshop.
But it's more than that too. I take pride in my work, nothing beats the satisfaction of coaxing the very best out of an instrument - and defects such as those found on these horns make my job that much more difficult, if not almost impossible,
And then there's the issue of you, the consumer, and your rights. Nobody buys a Rolls Royce and then expects to have to put up with wobbly steering at 70mph. I've always maintained that you get what you pay for - and in this case I truly and honestly believe that you're getting less than you paid for, and more than you bargained for.

So what d'you reckon is going wrong?

A client was gracious enough to lend me a copy of Keilwerth's video of their manufacturing process. Naturally I viewed it with relish!
I think I see precisely what the problem is. The tone holes are drawn very early in the manufacturing process - right after the bell and the body are formed from the sheet. Directly after that the holes are machined level and the tone hole rings are soldered in position ( and I am assuming here that the rings are level - have seen examples where the rings were badly fitted ).
After that, the separate bell and body parts go through a whole range of processes, whereby the pillars and fittings are attached, the bell section is fitted to the body and finally the keywork is matched to the horn before being sent off to the finishing department.
The whole thing is subject to a great deal of heat and manipulation following the fitting of the rings - and it's only natural to see how assorted stresses are imparted to the structure. This would explain the gentle curves of the tone hole warps, as opposed to the relatively sharp curves you'd see as a result of impact damage.
Now, I can understand the need to level off the tone holes and solder on the rings early on in the process - it would be tricky to jig the body parts up once the pillars and fitting are in place in order to solder on the rings and dress the tone holes.
What's needed is an oversized tone hole ring - one that's, say, 3mm taller than currently fitted. This can be fitted as per usual, early on in the process, and then dressed down with a suitably profiled die fitted to a handheld machine after the pillars and fittings are in place and the bell attached to the body. The extra height of the tone hole rings would allow for any warp to be ground out as the rings are brought down to their specified height.
Of course, it would involved some material costs - they'd need suitable dies for every size of tone ring, and handheld drivers to power them, and it would probably add about 30 minutes to the production run - but the end result would be gloriously level tone holes!
That's really the only answer I can come up with for now - and this assumes that the problem isn't due to the rings themselves being warped prior to fitting...in which case the problem would be far easier and cheaper to address.

Does this problem affect the SX90 - without the tone rings?

Not that I'm aware of - though I haven't 'officially' reviewed one yet. Looking at the manufacturing process I would tentatively suggest that there's a risk, but in any event it would be easy enough to rectify permanently by conventional methods.
From an entirely personal point of view as a player I feel the rings add nothing tonally anyway - and simply create more problems with regard to sticking pads. Mind you, it's a moot point now - they no longer make this model.

Have you told Keilwerth about your findings?

Yes, I've had correspondence with people at the factory and with executives at the ( now ex ) parent company stateside.
In the former case they said they'd examine their manufacturing process and report back to me. They apparently did so, but informed me that they could find no problems.
The email I got from the parent company expressed concern at my reservations, but thanked me for bringing the problem to light. I have had no follow-up to my response, so I cannot say if any changes in the manufacturing process have been made.

I believe that they're caught between a rock and a hard place on this issue. If they were to admit that there is or was a problem, then that would leave them open to every SX90R owner chucking their horns back at them.
If they don't admit to it, but subsequently claim something like 'improved tone hole accuracy' then that leaves them pretty much in the same boat.
The only commercially viable option is to say nothing and quietly resolve the manufacturing issue.
That being said, the addendum added on 8/04 points up yet another problem with the tone holes.

Are you sure it's a manufacturing issue? Couldn't the horns have got damaged somehow?

If the warps were a result of damage there'd be collateral evidence. If your horn took the kind of knock that could distort a tone hole then there'd be a corresponding distortion to the body. Such damage would be clearly visible - you can see what it would look like on the photo of the copper belled horn below. Another way of distorting tone holes is by bending the body of the horn - but this too would be highly visible, and tends to occur around the G-F tone holes ( sax bodies typically get bent around the mid section ). A bend on the bottom bow would be highly unlikely - the sort of force required to do that would result in a crushed bell.

Would you ever say if you'd seen one without warped tone holes?

Too damn right I would! ( See here ).

Have you ever managed to fix one?

Yes, I've been able to address the issue on a couple of examples that weren't too badly affected - and the difference it made was significant. Success depends on where the warps are and how deep they are...there's only so much I can do.

Addendum 03/12/02 :

I have supplemented this review with an article dedicated to the issue of warped tone holes, which explains in more detail the nature of the problem - and contains further details specific to the SX90R. It can be found here.

I have recently examined an alto variant of this model, with the black nickel plate finish.
Regrettably I found the same old tone hole problem. This is particularly disconcerting on this model as any attempt to level the holes from the top down would destroy the finish on the tone hole tops.
Even more disconcerting is that fact that this instrument is barely four months old...so the tone hole problem remains an issue.

The review of the tenor corresponds to my feelings about the alto - though I will add that the black nickel finish looks gorgeous!

Addendum 07/07/03 :

I had a client bring in a tenor, bought new in February 2003 which exhibited the same tone hole problems as detailed above. In this instance the low C and C# tone holes were affected - with the C showing gaps at the top and bottom of the hole, and the C# showing a gap at the top of the hole.

Lovely brushed nickel plate finish on the body though, very distinctive.

Addendum 27/08/03 :

I have recently examined another tenor - built in 2000, a special 'Anniversary' model.
Again it exhibited the tone hole problem, specifically on the low C, B and Bb holes, with the warp on the low Bb being quite severe.

I felt this model had far more 'zing' than the others I've seen thus far, particularly on the low notes ( when they worked ).

Addendum 31/03/04:

And yet another example comes under scrutiny - an Anniversary 'Edition 75' tenor, built around 2000, with a black nickel plated body and silver plated bell and keys. Looks very nice - but once again the toneholes exhibit the same old problem. The low C and Bb in particular were really quite badly warped.
Here's the low C - there's a substantial dip at both the front and the rear of the tone hole.
Might not look much, but bear in mind that a serious leak is one that you can slide a cigarette paper into...you could get a bit of card into these gaps!

Addendum 30/08/04:

My offer to examine SX90R horns brings in another example - this time a horn in the 109xxx ( purchased new around 2002 ) serial number range. This model features a copper bell and crook with standard brass body and keywork. Very nice it looks too.
On my initial examination I really thought I had at last found an example without the tone hole problem - and this proves how hard it can be to spot the anomaly in amongst the curves and reflections, because when I placed the test die over the low B tone hole I found a pretty major warp.

In this case it begins just left of centre of the tone hole, with its apex at the extreme right. A particularly difficult one to spot, given that as you look down the bell with the cup closed it doesn't show a leak on the lower portion of the pad.

Of more interest ( to me, at any rate ) was another anomaly I spotted on the G# tone hole. Have a look at the picture below.
Note the arrow, which points to the rim of the drawn tone hole. The tone ring is fitted onto the tone hole - and if you assume that the parent tone hole is level, then if follows that the ring ought to sit flush on the rim of that hole.
But look just above the arrow and you can clearly see a gap inbetween the rim and the lip of the ring.
Note too how the gap decreases away from the arrow - which means the tone hole ring has a rise in it.

So what's going on here? Up until now, and confirmed by what I've seen in the manufacturer's video, I've assumed that at some point the parent tone holes have been levelled off - and that warpage appears to be caused by stress imparted to the body later in the build process. But this picture indicates that there's yet another potential problem - that of the tone rings being incorrectly fitted in the first place.
As you can imagine, having the tone ring sticking up in this fashion completely destroys any hope of the tone hole being level - and this on the G#...one of the most critical tone holes on a saxophone.
I'd expect better - and if you've forked out several thousand for such a horn, so should you.

Something else caught my eye too - take a look at this shot of the low Bb tone hole. There's a crease just under the rear of the hole, as shown by the curved reflection about a centimetre from the base of the hole.
I wondered how that might have got there.
I tend to assume that any structural damage is down to the owner - but just how would you push a crease like this into a horn? Bear in mind that the Bb key cup sits over this hole, as well as the low B/Bb key guard.
To make a crease like this the owner would have had to crush both the guard and the key cup hard down onto the tone hole - and at the rear of the key cup too. Naturally such an impact would do a great deal of damage all round, but none of this was in evidence.
Oddly enough, the low Bb tone hole was level - but I wonder if it started off uneven and had been given a 'tap' at some point to bring the rear of the hole down?
I shall be looking out for more examples of this particular 'fix' in future.

As for the blowing - pretty much the same as the other examples, although this horn had a nice crackle to it - perhaps more due to the copper neck than the bell, and although it blew all the way down to the low Bb you could still eke out a good 20% or so more tone by squeezing the keys hard against their tone holes.
The owner hadn't played this horn much since purchase, so the pads were pretty much as new - but as time goes by the G# in particular is going to cause some considerable problems.
There is a possibility that the warp in the low B can be corrected by raising the body underneath the tone hole - which would leave a hump to match the removed crease on the low Bb!

Addendum 24/02/05:

An Anniversary Edition 75 alto finds its way into the workshop. This time it gets a full review, and whilst it's about the best example I've seen in terms of the tone hole issue, it still fell on a very warped low C.

Addendum 04/11/05:

A solid nickel silver bodied alto turns up on the workbench - and becomes the very first example of the series I've seen without the dreaded tone hole problem. Read all about it here!

Addendum 08/04/06:

A brand new standard SX90R ( 118xxx ) is brought into the workshop for a checkover and setup.
This example was much improved over the earlier versions I've seen, though I regret to say I still found a few issues worthy of comment.
The low Eb tone hole was slightly warped, with a gap of about 1 millimetre at the front and rear of the pad.
The reason for this warp is an incorrectly fitted tone hole ring, as can be seen on the photo on the left.
See that grey band just below the top of the tone hole? That's the side of the tone hole ring, and the grey band marks out the discrepancy between the top of the tone hole base and the lower part of the tone hole ring.
Had this ring been fitted correctly the tone hole would have been level.

Fortunately, the Eb pad is always held closed by its spring - so this discrepancy won't be too critical an issue for as long as the pad is in good condition. Trouble is, the Eb pad takes a lot of punishment in terms of moisture and gunk - and it will be necessary to change this pad more frequently than on a horn with a level Eb tone hole.

The low C tone hole was fractionally out, but I felt it was within reasonable tolerance after a slight dressing. It needed a dressing too, there were a couple of rough spots on the surface. It'll be fine, but it's still less than perfect.

Another place that had imperfections was the palm key tone holes. My attention was drawn to these by excessively heavy springs - and in order to back off the spring tension I had to remove the palm keys. I also had to address the problem of a seriously sticky top F key pad ( so sticky that the front F mech failed to open it ).

Upon removing the keys I noticed the F and E tone holes had burrs inside ( can be seen here as a rough white arc inside the tone hole ). The reason for the F sticking was the pad fouling in the tone hole burr. All that was required to remedy this was to remove the burrs with a fine file before smoothing over the bore of the holes.

In terms of improvement to build quality I'd rate this example as an 8 or 9 out of ten - though it's lucky that the badly fitted tone hole ring was on the Eb key. Had it been the low D or C it would have been a far more serious issue.
Overall though the quality control is still not up the the standard I would expect to see on a horn in this price bracket.

Once set up the horn blew very nicely. The balanced combination of a rich, warm tone coupled with a nice touch of edge makes this a very versatile tenor that will respond nicely to a wide range of mouthpieces. Without suffering the vagueness of earlier examples with more severe tone hole problems, the lower notes spoke with more immediacy and authority.

I still feel the action feels slightly large under the hands, and on this model the bell key action felt ever so slightly more sluggish. This would appear to be down to the fitment of a spring to the unusual G# anti-stick mechanism. It's a small point, but having felt a great many excellent bell key mechs I think I'd be inclined to remove the spring to put back a bit of snap into the action here.

So, a bit of improvement then, but still a disappointment to find quality control issues on a top-level horn - and as such I can still only recommend this horn with caution.

Addendum 09/01/07:

Another nickel-bodied alto arrives in the workshop - but unlike the previous example it exhibits problems with a couple of the tone holes. I have added it to the alto review here.

Addendum 15/01/07:

The latest example on the bench is a 'Vintage' model - so called because of the distressed finish to the plain brass body, similar to that seen on the Borgani Ponzol, whereby the body is 'dirtied up' and then lacquered. It has the effect of making the horn look instantly old, and ensuring it stays that way and doesn't get any grubbier ( where's the fun in that though?? ).
This model ( serial number range 123xxx ) was bought new in Dec.2006.

It doesn't look too bad, though probably not to everyone's taste, and the brushed matt finish on the keys certainly helps to make this a very distinctive looking horn.

From my initial inspection I suspected that what problems there were with the horn was due to poor action setup. Several keys were badly regulated, which caused leaks due to pads being held off closing by linked action.
This made the lower subtone notes insecure, and although the horn didn't sound too bad it lacked the zing it should have.
Tweaking the action helped matters greatly, particularly slackening off the excessive spring tension on the main stacks and bell keys - but a warp was found on the low C tonehole. Although a double warp ( photo left, warp on left side of tonehole hidden ), it wasn't as bad as those I've seen on previous models - and I would be tempted to say that this bodes well were it not for the recent alto model that shows a step backwards in terms on tonehole integrity.

An adjustment was made to the tonehole which helped to lessen the degree of warp, and this, along with an adjustment to the pad seat, really improved matters for the subtone notes.
Once blowing properly it was possible to fully appreciate the richness of tone throughout the horn, and the playful edge to the lower notes

As it stands, this horn represents an improvement, but I still find manufacturing defects of this nature unacceptable on a top-flight horn - and I shall keep watching...

Addendum 20/06/07:

Now this is interesting...this next SX90R to arrive in the workshop ( bought new in May 2007 ) is the same model as the one reviewed above - the 'Vintage'. This horn bears a serial number of 123xxx - and is approx 450 horns later than the model above.
If you make the natural assumption that the more horns Keilwerth make - the better they should be at it, then this model should be an improvement on the previous example.

In a word? NOT!

In point of fact this particular horn was the worst example I have ever seen. The reason it came into the workshop was because it barely blew much below low D - and here's why.
This photo show the low Eb tone hole; note the cavernous gap on the right hand side. There's another gap on the other side, though it doesn't show up on the photo.
This is bad enough, but this isn't even the half of it.

Not only was the low Eb tonehole completely out of true, so was the low C, and the low B...and the low Bb - and by a considerable degree. I didn't even bother to check the C#, or any holes above the Eb...there didn't seem to be much point.
When it came to deciding which tonehole anomaly to display I was quite literally spoilt for choice.
Bearing in mind that this horn was bought mail order ( from Germany ) I examined the horn carefully for transit damage. None was evident - the defects found were built in at the factory.

Leaving the build quality ( can I actually use that word?? ) aside for a moment, I was rather taken aback by the overall finish of the horn.
The 'pre-distresssed' finish has been around for some time now - and whilst I'm not particularly a fan of it, I can at least appreciate how some players would find it appealing...but I have to question where the line is drawn between a deliberately 'funky' finish and just plain sloppiness.
The photo on the right shows the bell section of the horn. Note the black splashes around the key guard stay and bell stay plate. These are what's left of flux/solder residues after the body has been dipped in a cleaning solution. You can clearly see what's called a 'wipe mark' to the left of the key guard stay...where the builder has wiped the soldered joint with a cloth to remove any excess solder. I call these 'witness marks' - they point up areas of repair.
If it were the case that an ordinary horn needed a parted stay resoldered, this is how the job would look immediately after the stay had been resoldered in position ( though many a repairer would have made rather less mess ) - and subsequent to the resoldering the area in question would be cleaned and polished.
There are marks like this all over the horn, and much as I like to be objective about esoteric finishes I feel that in this case someone is taking the piss - it's really not a nice finish at all.
A 'vintage' finish should be about treating the brass to make it look old and worn - if your old and much-loved Selmer came back from the repairer with these kind of witness marks you'd probably have a blue fit.

I did try to play the horn - if only so I'd have something good to say about it in the write-up - but it really wouldn't blow very well...the setup was absolutely atrocious.
I ended up advising the client to send the thing back on the grounds that it was a complete and utter disgrace - and recommended that if he wanted to buy a sight-unseen horn then he'd better stick to something from Japan...or get himself off to a decent music shop and spend a day trying out horns.
He did send it back, and the seller's technician agreed that the horn was awful and a full refund was made. He subsequently spent a day trying out horn in a shop and came away with a Selmer Ref.54 ( so he's not completely out of the woods yet! ).

So where does this leave the SX90R in terms of quality control?
I really had hoped that as time went by the manufacturer would address the issue of warped tone holes, but with this very up-to-date example being the worst I have ever seen it looks like there's been a step backwards, if anything.
I find myself applying the term Caveat Emptor to a horn that costs over £2000...and that's an appalling state of affairs.
I'm told that production is moving to a new factory shortly. I'm not holding my breath...

Addendum 17/03/08:

This SX90R Shadow bears a serial number of 121xxx, which places its build date somewhere in 2006 at a rough guess.
When this tenor arrived in the workshop it was barely working at all - it was a real struggle to get much below low F, and naturally I assumed it would be a problem with the tone holes.
But I was wrong ( pretty much ), because although this horn had a couple of tonehole issues the chief problem was the state of the action.
Practically every single key cup on the main stacks was at the wrong angle, resulting in the pads bedding down at the rear - which leaves a leak at the front.

Now, this horn has been in use for a couple of years - so I can't really point the finger at manufacturing problems, but I will say that such problems rarely come about of their own accord ( unless someone has taken a mallet to each and every key cup and given it a healthy whack ) - and that I've seen the same issue on quite new examples.
The problem is indicative of a pad that has been compression set - it's been placed in the cup and then forced closed against the tonehole, rather than heated and manipulated to lie level.
Pads set by compression tend to expand and thus lose their seat at one end or other of the tonehole - and the only fixes are to have the pads reset ( or the cup angles adjusted ) or use those dreadful key clamps to maintain the compression seating when the horn is in its case.

Because this horn played so badly the client was able to purchase it for a knockdown price ( I won't say what it was, it would bring tears to your eyes ) - but then discovered that the reason it played so badly might be down to warped toneholes...hence a nail-biting visit to my workshop!

And yes, it did have warped toneholes - but only a couple, and fortunately neither were so bad that they either couldn't be levelled or compensated for with a backed-up pad.
The biggest problem was the low D tonehole, with a slight warp to the front and the rear. Because of its proximity to the bottom bow joint it wouldn't be advisable to attempt to rectify matters by lifting the bore or tapping down the tonehole sides, so I opted for fitting backing wedges to the underside of the pad to take up the discrepancy. It took a while to get it just right, but it's a substantially cheaper solution than having to whip the bell off to remake the bottom bow joint seal. Not as permanent, mind you - whoever replaces that low D pad will have to ensure they shim it to match the profile of the tonehole rim.

Of more interest ( to me at least ) was the low Bb tonehole.
You can see to the rear of the tonehole that the body is clearly dented ( note how the light curves around the base of the hole ).
I've seen this before, on the copper belled model reviewed in 2004.
There's really only one way to get a dent like this in the body, and that's to give the tonehole rim a whack. Because of the placement of the key guard it's all but impossible to do this kind of damage accidentally - and in any case, if you did you'd warp the tonehole. As it happens this tonehole was level from front to back - which suggests that this dent has been deliberately made in an attempt to address a warped tonehole.

It almost worked - I had to raise the hole very slightly on the bell rim side to fully level it.
It still has to be said, a fix like this is unacceptable on a top-end horn.

Once the keywork issues had been addressed, and the tone holes accounted for, this horn blew as sweetly as any of the very best tenors I've played. The client, considering the price he paid for it, was over the moon. So was I, to be frank.
Note definition was superb - every single note had a nice sparkle, but there was also a deep richness there too. It almost felt as though there were two horns playing...one bright, one warm - and this carried on through right across the range.
I would say though that at subtone that sparkle was a little intrusive, and in a side-by-side test with a Yamaha YTS62 the Yamaha actually sounded warmer at subtone. Not by much, I grant you, but enough to surprise me. This was on the same mouthpiece though, and I would think that a larger chambered piece would quell that slight brightness if it wasn't to your liking.
It's an effortless blow too - very free-blowing and responsive, and I think for the very first time I actually enjoyed playing one of these horns. I still feel for me that the design and layout of the action makes the horn feel big under the fingers, but that's something that individual players will either like or not.

What's particularly frustrating about this example is that it shows what these horns are capable of. I can combine that comment with my recent experience at the Frankfurt Music Messe this year, at which I snuck onto the Keilwerth stand and gave their horns a good blow. They were featuring a 20th Anniversary Shadow with a solid silver crook which was just gorgeous to blow ( I checked the toneholes visually, they looked OK ) - perhaps one of the best horns at the show.
Contrast that with the previous addendum - the horn so bad that it got sent back to the manufacturers.
This is what's so frustrating, it's obvious that these horns are good...great even...when they work - but someone, anyone, at Keilwerth has to recognise that consistently good build quality is demanded and expected at this price level.
Let's not forget too this latest addendum example had build issues too ( fortunately largely correctable ) - and as such I do have to mark it down as a fail in terms of build quality.

If you own a Keilwerth SX90R series horn and are concerned or curious as to whether your horn suffers from warped tone holes, you are invited to bring it along to the workshop for a free inspection. In the course of the inspection I shall examine and test the instrument and take photographs as necessary, whereafter they will be added to the rolling reviews ( good or bad! ).
There will be no charge for this, and in return for your time I will carry out a setup and lubrication job on your sax free of charge.