XTZ Class A100D3 Amplifier - partial report [Archive]

Macca

12-01-2013, 23:21

Only partial? Yes that's right. So much going on with this amp I have not had the chance to try everything yet. But, here are is the story (almost) so far:

This is a big, heavy amp. I was warned to watch my back by a helpful member, unfortuately I still managed to stretch a muscle somewhere lugging this thing back home and into position. Giving me jip as I type...:(

As some will know I was after a really chunky power amp to drive my Celestions. They have seen off a lot of amps, integrateds and power amps. Look on the net you will see this in users comments and even in for sale adds 'difficult load, you will need a powerful amp.' The Linn LK100 I am using does a fair job but I have a large-ish room to fill and it is easy to hear it clipping on peaks sometimes. With seriously deep bass programme there is a little lack of bottom end definition, making things a bit to 'thuddy' to be convincing. I have a slight 'midrange bloom' as they say - slight but enough to irritate me a little. This may be down to the Croft pre amp though.

Also Dave DSJR is always banging on about the 'coarse and grainy' sound of the LK100 and that I should really be using something 'a lot better'. Whilst I don't agree that the LK100 is coarse and grainy, I do respect Dave's opinions and the Linn is perhaps a little old and outclassed in my system.

Nevertheless a Brio-R integrated jsut won't cut it in this situation so I had to look elsewhere. :eyebrows: One suggestion thrown up on my wanted thread was the XTZ Class A power amp. 112 watts into 8 oms 196 into 4 ohms, more currents than a Marks and Spencer tea cake, and switchable between class A and class B (or AB as they call it) modes. Euros 720 brand new delivered. :eek:Then I discover that for just another 60 Euros you can have the same power amp but with a built in pre amp section that has:

4 line level inputs
MC and MM phono stages
Built in DAC with 3 coax inputs and 1 optical
2 line level outputs for powered subs
Aluminium remote control

All on a sesame seed bun. (no, not really).

Now as Magnum P.I. always used to say: 'I know what your thinking and you're right.' Surely for 60 Euros this will be a cheap DAC and a load of integrated circuits and is no way better than my Croft pre. But for just 60 more euros I thought: 'what the hell lets have all the bells and whistles.' Plus - Take out the bridging link and you just have the power amp so no downside.

The first thing you do when you buy anything electrical is plug it in and see if it works. So I plonked it down, set to intergrated, class AB, hooked up a CD player and off we went.

Next installment tomorrow - same Bat Time, same Bat Channel...

isuckedmandelsonslemons

13-01-2013, 06:59

Excellent. Enjoyed reading that. You definitely have a gift for writing

Macca

13-01-2013, 08:55

Excellent. Enjoyed reading that. You definitely have a gift for writing

Thanks Harry. Knowing your background that is quite a compliment. I can't believe Alan Sircom turned me down! Seriously though any slight ability I might have to string words together is down to my having been fortunate enough to have received a very good Grammer School education, and nothing at all to do with my nascent genius (or lack of it ;) )

AlfaGTV

13-01-2013, 09:11

isuckedmandelsonslemons

13-01-2013, 09:20

Thanks Harry. Knowing your background that is quite a compliment. I can't believe Alan Sircom turned me down! Seriously though any slight ability I might have to string words together is down to my having been fortunate enough to have received a very good Grammer School education, and nothing at all to do with my nascent genius (or lack of it ;) )

Bring back the Grammar Schools. Them people will know how to spell :-)

RE getting turned down. I've wa turned down for a shitty PR job despite working as a newspaper editor and three years on the second best selling Sunday newspaper. That was because I didn't have a degree.

Anyway, very enjoyable read. Looking forward to next instalment.

Effem

13-01-2013, 11:25

I will be interested in the next instalment too Martin as like what I 'as the same bloomin' amp guvnor (:ner: to grammar sckool edoocayshun) :lol:

Macca

13-01-2013, 11:33

Bring back the Grammar Schools. Them people will know how to spell :-)

.

I gave my sub the day off ;)

Anyways, on with part two, I will attempt to make less typos this time.

First things first I want to outline my philosphy towards amplification as this is quite relevant to what follows. I am not really comfortable with describing the 'sound of an amplifier'. If the notionally perfect amplifier is a straight wire with gain, adding nothing to the sound, then by definition any amplifier that has its own sound is fundementally flawed. When we describe amplifiers as being 'warm', 'bright', 'Bass heavy', 'bass light' and so forth we are really describing the sound of the loudspeakers being driven by that amp and not the amp itself. Many people use woefully under-powered amps for they volume levels they play at, looking at the specs and saying 'well the speakers are 90dB and the amp has 40 watts out put so I will get 105 dB in room and that is plenty' but it just doesn't work that way in practice. You get clipping and distortion, making the sound 'hard' and collapsing the sound stage into a ball of mush between the speakers. Okay if you have a valve amp it clips more smoothly and doesn't sound so bad, but this is still something to be avoided and so my solution is to go for overkill on power and current delivery. It's the only way to be sure.;)

Consquently I was not expecting this amp to show night and day differences to the Linn Lk100. What I was hoping for was to gain some improvements in the following areas:
Bass distortion
Midrange bloom
Lack of headroom

So where were we? Oh yeah - I'd hooked up a Sony CDP761E. It already had a copy of 'All Saints - All Hits' inside as this was the last thing I had listened to on the previous amplification (Croft Micro Basic pre/Linn Lk100 for those not keeping up). A good recording, it is not massively dynamic but it does not suffer from loudness and it has some very well recorded female vocal harmonies plus some deep 'club' bass on some tracks so a reasonable first test.

First thing I noticed was that blacks were blacker. An old cliche I know but the noise floor drop (if that is what causes this phenomona) was marked. Track 2 'Never Ever' is a pleasing little piece of commercial hip-hop with a lot of unsupported vocal harmonies. These do sound utterly enchanting reproduced well, one of those little things that sets a decent sound system apart from an i-pod dock. However I thought they sounded slightly less beautiful then previously - possibly the Croft being missed here? It was the slightest of differences, though.

I ran throught the rest of the album, increasing the volume at one point to party levels just to see at what point things would break up. Quite astonishingly, there was absolutly no clipping, no collapsing of the sound, even though I knew I was playing very loud it did not sound loud, just 'big'. In the end I was worried about the loudspeakers so I backed off again without finding the upper limit. But there was never, ever any sign of strain. Marvelous!

A few more albums followed, Santana Abraxas once again showing up those blacker blacks, especially when Tito goes for it with the Tom Toms. I tried pushing the volume on this album too. with the same result, the sound just got bigger with no loudness/distortion evident.

Well it can't all be upsides and one thing I had noticed was that although I was getting a crystal clear and very hi-fi sound, it was, ultimately, a little too forensic and consequently just a little bit bland. I swapped interconnects from the Belkin Pure AV to Audioquest Turquoise. This usually makes quite an improvement. Not today, it didn't. I decided to try another CD player so hooked up a Sony XB930E QS with its fancy fixed laser mech. This has a digital out so I thought I would kill two birds with one stone and hook it straight into the DAC and see what that sounded like. I put the All Saints CD on again and sat back. Whoa! Now we were cooking on gas! Blandness gone, bass even better, deeper with more texture, female vocal harmonies sounding very pretty indeed. I wanted to walk to the other end of the room and start chatting them up. There was a 'fruitiness' to the sound (I know, but how to describe these things?) that was not there before.

I decided to jump straight to thebig one - Steely Dan's 'Gaucho' - Just tremendously good sound. The best I have heard this album reproduced was the DVD-A played through a friend's not dissimilar 'big rig'. Now this was only the re-mastered CD ( I have nothinf that will play the DVD-A) but it was so beautifully reproduced I was starting to think my can of Murphy's had been spiked...

I've never been much for the transport/DAC route in the past, this has opened my eyes a bit.

Still to come - testing the MM stage, testing in pure class A mode, and testing as a stand alone power amp with my Croft pre. So will leave it there for the moment. As always, your comments are invited.

Macca

13-01-2013, 11:44

I will be interested in the next instalment too Martin as like what I 'as the same bloomin' amp guvnor (:ner: to grammar sckool edoocayshun) :lol:

Never spotted that Frank - How long have you had it (the amp, not the edoocayshun) ?

lurcher

13-01-2013, 11:50

Interesting write up, more to come I guess, but without wanting to cause a argument, just interested in your view, how do you see the following statements from your text.

I am not really comfortable with describing the 'sound of an amplifier'. If the notionally perfect amplifier is a straight wire with gain, adding nothing to the sound, then by definition any amplifier that has its own sound is fundementally flawed. When we describe amplifiers as being 'warm', 'bright', 'Bass heavy', 'bass light' and so forth we are really describing the sound of the loudspeakers being driven by that amp and not the amp itself.

and

it was, ultimately, a little too forensic and consequently just a little bit bland.

First thing I noticed was that blacks were blacker.

The second two seem to be pointing to the amplifier itself having a sound.

Effem

13-01-2013, 12:12

Never spotted that Frank - How long have you had it (the amp, not the edoocayshun) ?

I have owned it for at least 2 years now Martin. I won't make any comments about your findings with this amp until you have had a chance to put it through it's paces in full :eyebrows:

Macca

13-01-2013, 12:28

Interesting write up, more to come I guess, but without wanting to cause a argument, just interested in your view, how do you see the following statements from your text.

and

The second two seem to be pointing to the amplifier itself having a sound.

Fair comment, Nick. To explain - I was not really suggesting that amplifiers do not have their own sound rather the notionally perfect amp has no sound. In the real world there will be differences. But not large ones. The large differences we attribute to amps are down to their ability to drive the given speakers.

The bland sound was due to the CDP I was using. When I swapped to transport/DAC this vanished, consequently nothing to do with the amplification.

If one amp has 'Blacker blacks' than another then to me means the amp has less of a sound of its own. I'm not technical (you'd never guess) but suspect this is either down to lower noise floor or lower distortion or both. i.e good spec and construction, it is not due to something deliberalty 'built into' the circuit as an artifice.

Hope that clarifies a bit.

Effem

13-01-2013, 12:32

:popcorn:
Good writeup! Reading with interest as i used to own its sister product, Advance Acoustic MAP 303 II, which only differs in spec'ing of some components.
(Though mine did not have the DAC part)

Regards //Mike

I owned the Advance Acoustics pre/power combo around 4 or 5 years ago and although they are probably built in the same factory as the XTZ to me they are a world apart in sound terms

Tim

13-01-2013, 12:34

Macca

13-01-2013, 12:35

I have owned it for at least 2 years now Martin. I won't make any comments about your findings with this amp until you have had a chance to put it through it's paces in full :eyebrows:

Well if you have had it two years you must think quite highly of it. :) I'll look forward to your comments, Frank.

Mike - H

13-01-2013, 12:37

I love my XTZ Class A100D3, it has really opened the world of CDs to me. For the last ten years or so I had been buying CDs, ripping them to mp3 and putting the disc away. I had a Cambridge A300 amp and its CDP mate and they weren’t very good to say the least. I bought a Azure 650 CDP, but mated with the same amp there wasn’t much improvement.

Step up the XTZ last July and wow! Blown away, even with my crap speakers. I’m also very happy with the MM stage, although I think the twin DACs in the 650 are a touch better than the built in DAC, maybe I should try a better optical cable. I think you will very pleased with the XTZ which ever way you use it, I can’t wait to marry it to some decent speakers to make use of the class A

Mike

Macca

13-01-2013, 12:45

Great write up Martin, one of these was on my radar 2 years ago when Frank recommended it to me. I wanted more oompf up my old Monitor Audio speakers, but worked out they needed more than a powerful amp to get them going, so I got them going off to eBay instead.

:D

Astonishingly good value.

Thanks Tim. Changing the speakersto something less demanding was the other option but to get something just as capable would be very expensive. Big Tannoy DC have been seriously considered. :eyebrows:Actually I would deffo swap them out for a pair of the big JBLs with the compression driver/horn cell mids but you rarely see them come up for sale, and never anywhere close.:(

Effem

13-01-2013, 20:12

OK then Martin here is my 'analysis' of my long standing friend the XTZ Desire.

Firstly, I will state that after 2.5 years this beastie has well and truly 'burnt in' by now I would hope whereas as I recall in your initial post yours was hot out of the box.

My XTZ sounds lacklustre and none too impressive from a cold switch on. A good 20 minutes in idle mode is essential before listening to it is the order of the day. When cold there is a small but perceptible edginess to the sound and the bass has a steel band wrapped around it so the bass is there but with a lack of flow. After that 20 minutes warm up it sounds very respectable and sounds lucid with plenty of detail in the treble and bass registers. Sound is always positive and powerful with great details throughout the audible registers and cranking the volume up doesn't raise the INTENSITY of the sound which leads to that "loudness " perception, but merely steps up the volume, so you can still hold a clear conversation with the person next to you. Have it quite loud and you can walk out of the room and close the door behind you and little of that high volume sound bleeds out of the room - a hallmark of a good system.

Oddly enough, the XTZ doesn't seem to shine that much at the bakeoffs I have taken it to. Indifference to it's charms seems to be the order of the day when partnered with other ancillaries. Strange. I have though spent a good few hours in a head-to-head with a Marantz PM17 and the XTZ wiped the floor with it no problem. I would rate this amp a lot higher than an MF Trivista 300 which I also owned a while back. I still to this day can't work out if the XTZ is that great or the Trivista isn't. Go figure :scratch:

I have only partnered this amp with 2 pairs of speakers, neither of which are demanding or difficult loads. A pair of Dali Suite 2.8s were a superb match in a room some 21 feet by 10 with a suspended floor and more area of glass than most rooms have. Punchy, tight, controlled, detailed, yet still managed to be intimate and palpable. These days it is paired with a pair of Focal Chorus standmounts in a room that is not much bigger than a box room so I am listening to the system almost in a near field configuration. Still sublime and :ner: to all of you who dismiss the Focal speaker range as being "bright".

Initially I was both pleased and surprised that the amp contained both a DAC and a MM phono stage but the DAC stage frightened the living crap out of me way back in March 2011 after owning the amp for only a couple of months. The thread I wrote about that incident: http://theartofsound.net/forum/showthread.php?t=10506&highlight=blemished A message was sent to XTZ who analysed a problem with the DAC momentarily losing signal lock with the incoming signal. A DAC should mute whenever the incoming lock is lost and I believe my report led to modifications being carried out on later Desire models. There is little if any difference in SQ between the DAC in the XTZ and the resident DAC in the Eastsound CD player so the importance of the XTZ DAC isn't great to me anyway.

I am no real fan of vinyl to be honest; not that I dislike the vinyl sound, or I am too lard-arsed to change LPs (lying bastid :eyebrows:), it just that the sheer cost of buying a top class vinyl rig, the storage of LPs when space is limited, etc., means that I rarely if ever want to go headlong into vinyl ownership again. This leads me on to trying the phono stage built into the XTZ which in pure honesty failed to impress. Whether it was the inexpensive deck/arm/cartridge combination underperforming or the phono stage lacking I could not ascertain, but the noises I was hearing shut the door on that particular route so I am hanging in there with CDs for the foreseeable future.

I don't think I have owned an amp before that was quite as sensitive and responsive to the cabling. It can easily sort out what is a 'hifi cable', what is a budget cable and those that have sophistication and finesse. I am a great fan of pure silver cables and have been for many years I might add, but this amp soon ferrets out which is real silver and what is not and it will also show up in great detail the differences between a hard annealed and a soft annealed silver cable to boot. It simply loves the TQ Blue and hated the TQ Black, whereas other forum members note the opposite in their systems. As for the interconnects, I am very happy with the Albedo Flat Golds which are a truly analogue sounding cable with their silver/gold alloy construction.

Of course the acid test of my thoughts on the XTZ are evidenced by whether or not I would recommend this amp to others. I did 2.5 years ago when I got it and still do, especially so given the performance available for the asking price. I'm not all that sure about the DAC and phono stage but then again it still to me represents outstanding value for money as an amp without those.

Macca

20-01-2013, 12:42

Thanks for contributing your observations, Frank. I agree about the 'talk over' aspect, although I know some regard this as a criticism rather than a positive attribute I personally like a 'clean' sound so all good as far as I am concerend.

Re your comments on the phono stage:

I have been putting the MM stage through its paces the past two days using a stock sl1200, rubber/cork mat with a Nagaoka MP50 cart in a Sumiko shell. (Total cost £400 so no need to spend a fortune to get very competent vinyl replay).

http://i903.photobucket.com/albums/ac233/Macca_photos_2009/xtz2001_zps349e9e2a.jpg

It's a generalisation but cheap phono stages are usually shut in, undynamic and, ultimately boring to listen to. This is what I was expecting. I was wrong. I'm getting a lovely, tidy, clean (but not clinical) sound with air and sparkle in the top. Bass is deep and well defined and I have no complaints about the dynamics. More than acceptable, in fact. It will be very interesting to compare this with the valve phono stage in the Croft micro-basic a little later in the week. Certainly the XTZ as an integrated is better than the Croft/LK100 combination with vinyl. How much of this is down to improving the power amp is debatable. A lot I suspect. Overall it is a very tidy and precise sound I am getting.

More to follow.

Effem

21-01-2013, 10:42

After 2+ years of total reliability my Desire developed a fault over the weekend :(

The left hand channel started distorting and cutting out, a light tap on the case restored it. I was expecting a dry solder joint on the power amp PCB so began the process of stripping it down. The top and side panels are fixed by small Allen bolts, then I was faced with more screws you can shake a stick at lurking on the base plate :eek: At the top corners of the amp are case plates that appear to have no screws holding them and I was getting rather concerned that the entire back plate and the front face plate needed to be removed before the power amp modules could be removed. Bugger.

I sent am email to XTZ in Sweden and much to my surprise got a speedy response, giving me in very broken English some instructions how to dismantle it and a couple of photographs attached that didn't tell me either what I really wanted to know. One of the photographs showed the output relay with a sentence stating that a dry joint or two would very likely be found on the connector pins and in this case they were spot on in that respect, so it is a well known problem it seems. Getting AT the solder side of the PCB was a world away at that point, so I renewed my quest to crack this amp open and get the repair done.

Beneath that top corner cover you have 3 slots cut out along the side edge and a torch showed me the slots were in line with 3 screws into the massive heatsink. Removing those 'hidden' screws released the top corner cover, then I could see 6 screws connecting the heatsink both to the chassis and the front panel, 2 screws into the rear panel and then 6 screws in the bottom panel and finally the heatsink plus PCB were now disconnected from the chassis. Well not quite, because although most of the low power level cables connected via plugs/sockets, there are a few heavier gauge wires soldered into the PCB and not much slack on them either, then the cables were clipped to the chassis with tie wraps too, so it meant standing the amp up and delicately rotating the whole shooting match to gain access to the PCB screws plus releasing even more screws between the output transistors and the heatsink. I tell you folks, if you removed all the countless screws from this amp it would weigh half as much :lol:

Anyway, a couple of judicious dabs with the soldering iron, a drop or two of blood from being 'bitten' by the PCB and heatsink during the rebuild and my amp now sounds as good as ever it did :eyebrows: I am still amazed that it took over 2 years for a simple dry joint problem to manifest itself and certainly won't be shocked if one fine day the right hand channel also has a similar time bomb ticking away now. Perhaps some prevention might be better than the cure.

Despite that, I still love this amp to bits :yay:

Macca

21-01-2013, 11:08

Effem

21-01-2013, 11:28

So I have something to look forward to then Frank :(

Nothing I hate more than kit packing in before say 10 years use at least. That's one of the reasons I use so much Sony gear, it rarely lets you down.

Had a really good vinyl session on the XTZ last night - it does miss some of the magic of the Croft on the phono stage, in particular guitar and vocals are not quite as vivid or real as with the Croft. What continues to please me is the lower mid and bass - this amp just burbles along un troubled, like a V12 powering a milk float.

It might well be that yours being a later vintage Martin that these minor issues have been sorted out now.

Had a fair few Sony components with dry joints through my hands too and what annoys me is that flow soldering is not a new build technique that has yet to be refined so why after all these years do we still find dry joints?

At least you have confirmed that the phono stage works a darn sight better than my experience of it, so hopefully at the next bakeoff I attend there will be a better class of vinyl rig to feed into it, which might spur me on to invest a few quid in another deck :)

Macca

21-01-2013, 11:57

Let's hope so! Incidentally, do you use the amp in class A mode?

Effem

21-01-2013, 12:10

Let's hope so! Incidentally, do you use the amp in class A mode?

It is permanently set to Class A mode Martin and have yet to have it switch to AB by itself when the going got tough :eyebrows: My speakers are not power hungry anyway and my listening room isn't cavernous either to be honest, although at a couple of bakeoffs I took the handbrake off and still wouldn't switch when left on auto.

Macca

21-01-2013, 12:23

: My speakers are not power hungry anyway and my listening room isn't cavernous either to be honest, although at a couple of bakeoffs I took the handbrake off and still wouldn't switch when left on auto.

Just been looking your speakers up. Interesting review here (although you probably read it already):

http://www.theabsolutesound.com/articles/focal-chorus-706v-loudspeaker/

Firebottle

21-01-2013, 13:54

I've just looked up the Focal Chorus 706V and can get a pair in France for €189.
That sounds like a very good buy :)

AlfaGTV

22-01-2013, 08:15

It is permanently set to Class A mode Martin and have yet to have it switch to AB by itself when the going got tough :eyebrows: My speakers are not power hungry anyway and my listening room isn't cavernous either to be honest, although at a couple of bakeoffs I took the handbrake off and still wouldn't switch when left on auto.

Since the construction allows the amp to operate in a sliding bias mode, how would you be able to tell whether is running in Class A or AB?
The switch allows you to force the amp into a low bias mode when set to Class AB, does it not?

Think i published measurements on this amp somewhere... Hm....
http://www.ollars.net/hififorum/xtz.jpg

You'll figure this out i think! ;)

Regards //Mike

Effem

22-01-2013, 08:57

No doubt the graphs are indeed true Mike :)

My only point of reference as a listener is what the display says as it switches between classes A and AB, even though in reality it may have long since switched out of Class A mode in the background due to it's sliding bias arrangement

Mike - H

22-01-2013, 08:59

AlfaGTV

22-01-2013, 09:25

AlfaGTV, the amps tells you on the front screen which mode it's running in

I would say the amp tells you what mode it's set to, not what its currently running in...
But i wouldn't swear to that! ;)

Regards //Mike

PS
Effem, i agree with your writing fully!
And let me also add; the amp is a brilliant one, when looking at the cost, it becomes a steal!
The measurements are way better than the cost suggests! I mean, 58 Amperes current in both polarities, thats excellent engineering!

Macca

22-01-2013, 13:19

Interestingly XTZ quote 50 watts power output when used in class A wheras the Hi-Fi World bench test states that the amp outputs the same power whether in class A or AB.

Personally I have never found the big claims that some make for class A operation have any basis in audible reality. With this amp crossover distortion in AB mode is so low it should not be audible anyway.

AlfaGTV

22-01-2013, 20:33

Thats true Macca, they sound very well indeed in AB operation and to me, somewhat more lively that way.
However, i'm sure XTZ has got it right, they deliver something like 50W in class A, but since they "slide" into AB mode when power requirements demands it, they still deliver similar power whether the mode is A or AB.

Now, 50W of Class A power is not to be dismissed, it'll drive your speakers pretty loud, probably louder than comfortable. :)

Regards /Mike

Macca

06-02-2013, 13:42

A bit of a lack of updates on this as I have got slightly bogged down trying out various transports into the on board DAC. I hooked up a Samsung Blu Ray player via optical link (it doesn't have a coax!) with high hopes as supposedly these modern transports have very low jitter but the sound was a little unfocused and soft in the bass. A bit disapointing. I then tried a Sony 761E, again using the optical connection, and the difference was quite unbeliveable. As Phil Mitchell might say 'I can't believe I'm hearing this!' I now have the best sound I have ever heard from CD, not just in my system but anywhere, anytime. Really superb sound from top to bottom.

AlfaGTV

06-02-2013, 18:57

isuckedmandelsonslemons

06-02-2013, 19:22

I now have the best sound I have ever heard from CD, not just in my system but anywhere, anytime. Really superb sound from top to bottom.

That's great to hear. If you're ever in my neck of the woods we may be able to do even better ;-)

Macca

07-02-2013, 08:32

:)
I wasn't expecting that? But of course that raises the amp's value for money even higher!
I thought the DAC section (along with the RIAA) were quite rudimentary on this amp...

Well, congrats and enjoy the music!

Regards //Mike

Yes my thoughts too but I suppose to some extent a DAC is a DAC. More surprising really that there should be a difference in the transports if bits are just bits. Spent another couple of hours last night playing through another half-dozen CDs and there can be no doubt, it is not just wishful thinking on my part. I think it is the way that reverb and decay are reproduced, just sounds absolutley right.

Macca

07-02-2013, 08:33

That's great to hear. If you're ever in my neck of the woods we may be able to do even better ;-)

I've no doubt, but those Ushers of yours are in another league alltogether of course.

isuckedmandelsonslemons

07-02-2013, 12:51

I've no doubt, but those Ushers of yours are in another league alltogether of course.

True. But I meant the front end. It sounded pretty good with my old Castle Howards.

Macca

07-02-2013, 12:58

True. But I meant the front end. It sounded pretty good with my old Castle Howards.

This is better than 'pretty good' though. I've had 'pretty good' for years.

isuckedmandelsonslemons

07-02-2013, 13:01

Ah but it's all relative. Your pretty good might be less good than my pretty good. Or it good be more good. On the other hand it could just be average.

Anyway you're right. It sounded pretty good compared to with the BE10s. At least I know I didn't waste my money :-)

Anyway, if ever you're passing. . .

Macca

07-02-2013, 13:08

If I am ever passing don't worry I will be banging on your front door.

isuckedmandelsonslemons

08-02-2013, 05:57

Martin, any time.

DSJR

08-02-2013, 12:31

At least we now seem to have a genuine alternative to Sounthend's finest at this sort of price - £500 - £700?

Class AB today shouldn't be frowned at, since modern power transistors are apparently far more capable and intrinsically better matched I understand, crossover distortion being of extremely low levels before you even start to bias them. DAC chips are also apparently far more of a kind and not expensive to implement if the designer knows what they're doing.

You can't beat a good bit of carefully applied power, so thanks so much for the mini-reviews. At least I have another genuine alternative to suggest and hopefully it'll wipe the a*se off a Kandy in current form!

Macca

08-02-2013, 13:00

You can't beat a good bit of carefully applied power, so thanks so much for the mini-reviews. At least I have another genuine alternative to suggest and hopefully it'll wipe the a*se off a Kandy in current form!

Interestingly the overall 'tone' of the system with the XTZ is very reminicent to an all Roksan (pre, power and CDP) system I heard in a dealers about 10 years ago. Not sure what the 'speakers were, WAF towers with twin white drivers.

Macca

29-03-2013, 12:46

Not updated this in a while, I have not been listening to much music last month as the cat died after a short illness and I just wasn't in the mood. However now feeling a bit more cheerful and re-visiting the system this week just gone it has impressed me all over again. I was playing the Red Hot Chilli Peppers album 'Blood Sugar Sex Magic.' For those not familiar this is a very well recorded, cleanly produced slice of modern funk-rock with a lot of superb bass-guitar driven tracks. You could not really want for more, great bass texture and terrific dynamics, a really propulsive sound. I was captivated immediately. Even with the volume up at no point did the sound wimp out, grow coarse or fluff it even slightly, this makes me happy as this was the reason I opted for the XTZ in the first place but of course specs can only tell you so much.

My original intention was to use this amp as a power amp with my Croft Micro but I have really not had the desire to try this combo as the integrated XTZ is doing such a fine job. Plus remote control of volume is an unusual luxury I am not keen to abandon in a hurry ;). However I will attempt to hook up the Croft this weekend and see what it can bring to the party. I suspect it might improve vinyl playback at the very least. I also intend to try a fancy power lead on the XTZ, I'm a sceptical about that making any improvement, but I ascribe to the view of don't knock it till you try it.

AlfaGTV

29-03-2013, 20:37

Martin, you ought to try changing the small I/C which connects the Pre and Power sections. I purchased a small Van Den Hul "The Link" which made a BIG improvement!

Regard /Mike

Macca

30-03-2013, 08:32

Martin, you ought to try changing the small I/C which connects the Pre and Power sections. I purchased a small Van Den Hul "The Link" which made a BIG improvement!

Regard /Mike

Cheers Mike I'll take a look for one of those. :cool:

Macca

09-06-2013, 09:55

Okay so the fun continues with this XTZ amp.

As I mentioned in the opening post I actually wanted a power amp but as it was only £60 more for the integrated I bought that instead. So I separated the pre and power sections and installed my Croft micro-basic in the pre-amp role. This was a couple of weeks back and much listening in between. I like to listen to a wide variety of material before making any comments as it is all too easy to jump to conclusions with kit on the basis of one test track.

So - Crofty valve goodness - how did it sound? First up on the turntable was Aztec Camera's 'Love' as this was the last thing I had played through the XTZ's phono section. As soon as the needle hit the record it was a 'whoa' moment - so much more open and vibrant it really wasn't funny. Not only was there superb openness and delicacy in the top end there was also some of that highly prized but oh so rare fillagre detailing! It's ben a long time (17 years) since I last owned a system that did filigree detailing. With extended listening this was confirmed - the top end was superb, I could really hear now what the Nagaoka MP50 is capable of. Unfortunately it was not all love and roses. Mid bass was a little too heavy and really low bass was lacking. Playing Bob Marley's 'Uprising' I almost managed to get some bass boom - and I never get bass boom. There was also the impression, very slight but there nonetheless, that the sound was perhaps a little untidy, slightly raucous in fact. However listening to Sade's Diamond Life I did find myself thinking 'Christ this sounds amazing.' But...I'm not sure that 'Diamond Life' actually sounds like that - in fact I know it doesn't, I have the CD too.

Now I have heard the micro-basic in a number of systems and whilst it is not the last word in neutrality I have never heard it sounding so coloured - not in bad way - in fact the presentation would really appeal to a lot of people who want 'the music' as an event happening right now in your room rather than a hi-fi playing a recording, because that was the effect. I was tempted to have a play with the interconnects twixt pre-power (I was using Audioquest) as I have found the Croft to be quite sensitive to cable changes. First however I played a few CDs as I wanted to check that there was not too much gain on the line level - a problem I have encountered with a coupel of power amps previously. Unfortunately there was too much gain giving zero room for maneuver on the volume. Indeed loudly mastered recordings just were not working at all giving call the police levels with the knobs not even off zero. Bummer. Although my main listening is vinyl I do have a lot of CDs and I do enjoy them so this was a problem.

I started to consider the purchase of a Croft series R pre, as that is supposedly more refined sounding and has less gain - or maybe the Croft phonstage and run that into the XTZ pre amp, giving in theory the best of both worlds. First though I thought I would hook up my trusty Linn LK1 (as it was just lying around to hand) and see what that brought to the party.

Well blow me down. This turned out to be the Goldilocks combo i.e 'just right'. Okay with vinyl I was not getting the fillagree detail anymore and cymbal decay was a little dry - just a little but clearly inferior to the Croft in the top end. Everything else was superb, particularly the lower mid and bass which were now spot on - when a kick drum sounds like a kick drum and not a thud you know you are getting somewhere. The power amps ability to handle dynamics was now brought to the fore. It really is amazing how this amp drives the speakers even on massive musical climaxes it just stays completely together, never losing the sweetness of the notes or hardening the harmonics - quite breathtaking. With CD there was still a bit too much gain - I am guessing by now the XTZ power amp is quite sensitive - but there was enough room to choose between 'background level' / 'a bit of bite' / properly loud. Bass on Walter Becker's '11 Tracks of Whack' - holy Christ I have never heard anything like it, outstanding depth, power and control.

Essentially the sound with the Linn pre hooked up was pretty much in the middle ground between the XTZ which was a little dry and bland and the Croft which, although superbly open in the top end was also just a bit too warm and rosy for it's own good. So the Linn/XTZ is the combo I have settled on for the moment. Overall I think this is the best sound I have ever had - Although I do want that filigree detail back. Hmmm....

So to conclude I would heartily recommend the XTZ power amplifier. It is a revelation, and at the price it is a true giant-killer. As an integrated I would not recommend the XTZ, as the pre amp section simply does not do justice to the power amp at all. If you are considering it then I would suggest you save the sixty odd quid and just buy the power amp, and source a quality pre elsewhere.

Ali Tait

09-06-2013, 11:06

A bit of valve rolling might give a better sound from the Croft?

Macca

09-06-2013, 11:16

A bit of valve rolling might give a better sound from the Croft?

I think it is at least in part a gain issue - would different makes of valve potentially cure that?

Ali Tait

09-06-2013, 11:25

Depends what it uses?

Macca

09-06-2013, 11:35

Not sure - there are 3 of them. One is an EC83 - an Edicron, I can't make out the others although the line stage seems to be a GEC something or other from the logo.

Ali Tait

09-06-2013, 11:53

ECC83 can be swapped out for 5751, which is a lower gain equvalent.

Macca

09-06-2013, 12:14

Sounds like it could be worth a try then.

Ali Tait

09-06-2013, 12:48

Aye, might be that the 83 is in the phono stage though, sure someone will know.

Macca

09-06-2013, 12:52

I think it is. I know the line stage is just one valve that does both channels so that might narrow it down.

Ali Tait

09-06-2013, 12:57

Well, if it's an 83 as well, it'll be worth trying a 5751.

Macca

09-06-2013, 13:08

Took the top of but is still hard to read looks like it is a JAN 596 something, cannot make out the last number, might be a '5' - The phono is 2 Edicron ECC 83.

Audioman

09-06-2013, 13:14

Best thing is contact Glenn Croft. I have read he can provide his preamp with reduced gain so whether this involves more than a valve change I don't know. I heard a system with Techie and XTZ at Scalford and to me it sounded closed in and lacking detail. Put it down to the Technics but might have been the preamp. At little more than the price of an XTZ power I would suggest trying Rotel's current 200W model. (£675). Past form and the sound I get from an old integrated suggest this may be good matched with a quality pre amp. No having to deal with Sweden if something goes pop.

Macca

09-06-2013, 13:25

I'm not sure that it's worth sending the amp back to Croft. I may just buy a whole new pre-amp instead. I think that the system as a whole is now good enough to warrant it.

The Rotel amp looks good value as an alternative to the XTZ but I don't think it can swing as much current and it doesn't have the option of class A operation either - not that it matters much to me but some think class A sounds better.

Canetoad

09-06-2013, 20:00

Martin, I can tell you that the Micro 25 has 3 ECC83 valves. I have 3 5751s if you would like to try them. :)

AlfaGTV

09-06-2013, 20:50

Macca

09-06-2013, 21:07

Martin, I can tell you that the Micro 25 has 3 ECC83 valves. I have 3 5751s if you would like to try them. :)

Thanks Bernie but I have the Micro basic which is different to the Micro 25 - the line stage doesn't use an ECC83.

Macca

09-06-2013, 21:09

Martin, i had the same issue as you with another tube based preamp! I purchased a pair of Rothwell attenuators that gave me a perfect gain, giving background at 9.00 o'clock, listening at 10-11 o'clock and party at "noon" ;)

They're not even expensive! regards Mike

I have some Rothwells somewhere and have used them on the Micro but found they did degrade SQ a bit too much. Although that was with a different power amp. If I can find them I will give them a go. Cheers Mike.

vacdac

01-07-2013, 18:03

Thanks Martin...this thread has been an interesting one for me as I've been running an XTZ AP100 power amp for over 2 years now. I've had my current MF A1fbp pre for a similar period of time buying it shortly after the AP100. I'd previously been using my MF x-cans v8 as a simple valve pre-amp overcoming its single input by using my Audiolab 8000AV Processor/Dac as a remote controlled source switcher as it works entirely in the analogue domain to do this via its tape outs.

Lol this was only ever meant to be a temporary solution but stayed in place for a year & a half, seeing off several more flexible alternatives until I bought the A1fbp BNIB at a stupidly low knockdown price from Unilet. One advantage worth stating with the XTZ AP100 is that its a fully balanced design whereas its integrated sibling doesn't offer a balanced input option for its power amp section.

For the first couple of weeks after buying the A1fbp I used it via its single ended inputs whilst I was waiting for my balanced cables. It was obviously substantially better than my previous pre-amp. Running balanced however the noise floor seems slightly improved & resolution of detail/separation & drive also seem clearly improved. This is great news for me for low level late night listening, which is summat I greatly enjoy & which my current setup seems to excel at.....Which is not always what you end up with IME when pairing meaty S/S amplification with fairly inefficient speakers which are also a tough load, such as my XTZ 99.36 mk.ii Piano or indeed I'm guessing as your own lovely Celestion A2's. (I know t' Celestion A3's are a true 4ohm load, same as my XTZ's)

I'd be curious as to your own thoughts re how you feel your amp/speaker combo stacks up for low level listening? Particularly so if like myself you enjoy doing so late at night when all the ambient daytime background hash is largely absent & you can fairly check out how capable your system is in this respect.

Finally....I think that if your speakers are a true 4ohm load as mine are then they should be seeing more like 87.5watts Pure Class A as the XTZ manages a v healthy 75% increase in output power as the impedence halves from 8 to 4ohm.

All the best.

Chris W.

Interestingly XTZ quote 50 watts power output when used in class A wheras the Hi-Fi World bench test states that the amp outputs the same power whether in class A or AB. Personally I have never found the big claims that some make for class A operation have any basis in audible reality. With this amp crossover distortion in AB mode is so low it should not be audible anyway.
Thats true Macca, they sound very well indeed in AB operation and to me, somewhat more lively that way. However, i'm sure XTZ has got it right, they deliver something like 50W in class A, but since they "slide" into AB mode when power requirements demands it, they still deliver similar power whether the mode is A or AB. Now, 50W of Class A power is not to be dismissed, it'll drive your speakers pretty loud, probably louder than comfortable. :) Regards /Mike

Macca

14-07-2013, 11:25

I'd be curious as to your own thoughts re how you feel your amp/speaker combo stacks up for low level listening? Particularly so if like myself you enjoy doing so late at night when all the ambient daytime background hash is largely absent & you can fairly check out how capable your system is in this respect.

Finally....I think that if your speakers are a true 4ohm load as mine are then they should be seeing more like 87.5watts Pure Class A as the XTZ manages a v healthy 75% increase in output power as the impedence halves from 8 to 4ohm.

All the best.

Chris W.

Hi Chris

Just seen this so apologies for the late reply. I was unaware about the balanced inputs on the power amp version, worth knowing for those that are inclined to try it. I don't listen late in defference to my neighbour, also listening 18' or so from the speakers I have to have the volume up a little bit just to account for losses over distance. I like the physical aspect of listening to music, that's a big part of it for me, so I don't really do low-level listening at all, unless I have guests around, the system is adequate for 'background' music in that situation, but it would not amaze.

As regards speaker load I don't know about the A3 but suspect it may be an easier load than the A2 which does require some considerable current swing which as you say the XTZ can do. If the amp is not up to it the result is either weak bass or dull top. My only concern in running the amp full class A would be a reduction in service life, it does get very warm when used in class A for any length of time.

Regards

vacdac

14-07-2013, 12:29

Cheers Martin.....it was starting ter feel somewhat lonesome:lol:......many thanks for your response.:thumbsup:

Yeah the AP100 power amp is actually a true ground up fully balanced amplifier as is my MF A1fbp pre-amp. Using both fully balanced as opposed to single ended does bring v worthwhile SQ gains, the noise floor is lower & overall resolution is improved. Both my main Dacs in this system also offer balanced outputs & again sound a tad better hooked up this way. I use the additional single ended/phono outputs on my Cambridge Audio Stream Magic 6 Dac/Streamer to feed my MF x-10 v3 tube buffer as an occasional alternative to add a bit of 'valveyness' whenever I fancy. (I'm considering an Eastern Electric BBA/Icon Audio BB2 'Musical Box' as a future upgrade........the BBA would also allow me to gain match with the SM6's balanced outputs & level matching would make future A/B'ing more meaningful/straightforward.

Yeah agreed some deference to the neighbors is important.......I'm lucky enough that my neighbors seem happy to give me latitude to crank it up a fair bit fer daytime listening up to the middle of the evening & I tend to tone it down from 8/9pm onwards. I've never had a complaint once from my neighbors & this is a state of affairs I'd like to continue & it's good that we 'rub along' so well.

This does make it important for me to have a setup that is well resolved/enjoyable to listen to at low volumes, particularly as my evenings are generally more biased to music than TV fer the most part & I particularly enjoy reading a few chapters of my current book with some good toooonz for the last coupla' hours before beddybyes.

All the best Fella! :)

Chris W.

jandl100

14-07-2013, 21:42

I should be getting an XTZ A100D3 integrated tomorrow in a swap deal. I shall report back how it gets on with my MBL speakers. :)

vacdac

14-07-2013, 22:32

That'd be great Jerry......it'd be good to hear your thoughts on how it stacks up against some of the exotica you've had through your rapidly revolving doors.:lol: Hope it gels well with t' MBL's & gives a decent account of itself!

ATB

Chris. :)

I should be getting an XTZ A100D3 integrated tomorrow in a swap deal. I shall report back how it gets on with my MBL speakers. :)

jandl100

16-07-2013, 05:44

Well, I've got it. Won't be able to plug it in for a few days. :(
My god - what a hefty lump.
Fantastic looking build quality. Just amazing for the money.
-- it reminds me of a Karan integrated -- on steroids!

Mine's black - it looks Darth Vader's amplifier! http://yoursmiles.org/hsmile/starwars/h1508.gif :eek:

http://imageshack.us/scaled/medium/690/dd8w.jpg

AlfaGTV

16-07-2013, 08:02

My god - what a hefty lump.
Fantastic looking build quality.
...
-- it reminds me of a Karan integrated -- on steroids!

It surely is a hefty lump, but dont belive for a second that it will sound like a Karan! ;)
It will sound good for the money though!
Looking forward to readong about your impressions!
Regards Mike

jandl100

16-07-2013, 11:34

It surely is a hefty lump, but dont belive for a second that it will sound like a Karan! ;)

That's good - I don't like the Karan much :lol:

AlfaGTV

16-07-2013, 15:09

:D Haha! Well, i do! And on the other hand i still feel the XTZ to be a decent interim solution. For the money it commands, 'better' sounding 2nd hand gear can deffo be found, though.
But of course, it's a subjective sport this! I'm pretty sure you will like it, but it's a love likely to be forgotten quickly.
Regards Mike

jandl100

16-07-2013, 16:08

Ooo 'eck - I just couldn't resist wiring her up. :eyebrows:

Warm her up for 20 minutes as per recommendation, and on goes Eddy Louiss' Blues for Klook, volume at +32 :mental: .....

Loadsa power, really grippy. Awesome bass, I mean really deep and powerful and tautly controlled. A touch of grain in the treble, maybe that will clear up as it gets warmer? - but still really fast and clean, not harsh or aggressive.

This beastie cost me £375 - that is totally ridiculous! :eek:

Much more listening to do, of course, but I think I'm going to have fun here. :D

Macca

16-07-2013, 16:37

Hi Jerry

If you have time would you try it as a power amp with the Tilsbury passive pre? I'd like to know if this combo works as it is under consideration at the mo

Thanks

jandl100

16-07-2013, 19:32

yep, Martin - I should think I'll have time - I haven't put it up for sale yet! ;)

It'll be a few days, though.

jandl100

16-07-2013, 20:05

Some further thoughts after more extended listening to a range of music ...

It's a fine amp, it really is.
I've heard some quite expensive and/or very good sounding amps in my system, but imho no-one who has the relatively low price XTZ amp should feel embarrassed at the fact!

But, improvements could be had in the following areas, imo -->

- more open and extended at the top end. It's a bit cumfy at the top, which is better than being too bright, but it dampens the musical excitement and pizzaz a bit.
- more depth of field; images are well focussed left to right, but the soundstage is a bit 2D
- richer tonality in the mids, it's a bit dry and matter of fact
- even better bass; my Krell 250wpc amp has better control, slam and shudder, and goes a bit deeper. But the XTZ is damn good in the bass already.

It'll be interesting to see what bypassing the pre-section will do.
And then there's the DAC. And the phonostage.

Nice amp. :)

Macca

16-07-2013, 20:15

yep, Martin - I should think I'll have time - I haven't put it up for sale yet! ;)

It'll be a few days, though.

Thanks Jerry. I'd just like to know what the compatibility is like i.e is there enough gain, no need for an extensive report ;)

jandl100

16-07-2013, 20:24

Thanks Jerry. I'd just like to know what the compatibility is like i.e is there enough gain, no need for an extensive report ;)

Ah well - I can't answer that. It all depends on the overall gain structure of your system including the sensitivity of your speakers, as well as how loud you want it to go and how big your room is.

My Tisbury passive is out on loan at the moment (I have a Glasshouse passive as well), but I'd be happy to have the loanee send it on to you to have a try with once they are finished with it if you'd like. :)

Effem

17-07-2013, 12:50

realysm42

17-07-2013, 13:21

Are you keeping the Krell Jeremy?

It seems to have stayed with you for quite some time (by your box swapping standards)!

jandl100

17-07-2013, 20:39

Are you keeping the Krell Jeremy Jerry ;)?

It seems to have stayed with you for quite some time (by your box swapping standards)!

Yep - the Krell is a "keeper" - with a good passive pre it's the best I've heard my system sound.
The XTZ is good, but it's not that good. :eyebrows:
I fully expect to still have the Krell a year from now, whereas I am sure the XTZ will have moved on. :wave:

Macca

18-07-2013, 17:22

Ah well - I can't answer that. It all depends on the overall gain structure of your system including the sensitivity of your speakers, as well as how loud you want it to go and how big your room is.

My Tisbury passive is out on loan at the moment (I have a Glasshouse passive as well), but I'd be happy to have the loanee send it on to you to have a try with once they are finished with it if you'd like. :)

Thanks Jerry that would be great. If you don't still have my address send me a PM when you are ready. Cheers.

Macca

18-07-2013, 17:25

My experience with the XTZ is that it's rather fussy when it comes to cables. It sang with TQ Blue speaker cables and sounded flat with the Blacks. Any old interconnect won't do either and it was only when I stuck in the Albedo Flat Gold i/c's that it came to life. A "brighter" pair of i/c's sounded a tad grainy.

Hi Frank

I've found the pre amp section to be a bit bass shy compared to external pre amps I've tried. Not tried any different speaker cables although I could, I suppose. I see you are Thuling around now ;)

realysm42

19-07-2013, 08:17

Apologies for the mistake Jerry!

I'm impatiently awaiting the Sanders amp today, 1st time I'll have had a power amp in the system!

I'm also going to try a different angle of attack, no pre-amp in the chain; simple is better (supposedly) and will be using Jrivers 64bit volume.

You gents ever tried that approach, when using power amps?

Effem

19-07-2013, 10:33

Hi Frank
I see you are Thuling around now ;)

Yes Martin, I am very pleased with this little Thule amp. When I sold the XTZ there was a huge sense of foreboding what I was going to get as replacement for the XTZ that had the same welly and musicality. I spent many hours on ebay rejecting a vast amount of amps I knew wouldn't fit the bill and this Thule was another one of those "collection only" listings that mercifully the vendor agreed to letting a courier collect. It had the original shipping box so it was laziness really that he couldn't be arsed to post.

The reviews say the Thule has a prodigious bass output and they are not wrong, but in my tiny room with some small JBL standmounters it works beautifully :)

Macca

19-07-2013, 17:03

Effem

19-07-2013, 19:43

Hi Frank

They have a good rep the Thule although I've not heard one meself. I guess you sold it to Jerry? Anyway I think the XTZ overkill power wise for your system - it is a watts and current amp on the cheap really, for people like me who won't spring for big Musical Fidelitys or Krells. Don't belive in this 'musical' amplifier thing though as I said at the start of the thread. Amps for me are like engines - it will either drive the car along satisfactorily or it won't, a bit simplistic I know but that's me :)

Really am pleased with the little Thule to be honest. It certainly puts plenty of other amp I have owned in the shade.

I didn't sell my XTZ to Jerry, I sold mine on ebay to a chap who was most insistent on buying it for not much less than new price :mental:

I am sure I read that Jerry got his XTZ integrated through some sort of swap deal.

jandl100

27-07-2013, 06:49

Macca

27-07-2013, 07:32

I've just got back from a week away, and turned on the ol' stereo - which was still wired up with the XTZ amp.

A/B comparisons aside - it sounds fab, it really does. :scratch:

I have to conclude that I could easily live with the XTZ for the long term if my boxswap-fun had to be curtailed. :)

I can't hear any difference between 'class A' mode and class AB, this perhaps related to the sliding bias arrangement previously described, so given the big difference in heat dissipation, and hence presumably leccy useage, I always have mine on in AB mode.

Yup, I got mine as part of a swap deal with a Wammer for my Ming Da 18W SET valve amp. The XTZ certainly drives my speakers better than the Ming! - but then my speakers are designed to work with hundreds of solid state watts.

That concurs with my findings re the class A option, I came to the same conclusion. It does puzzle me when people refer to the 'quality of the watts' when talking about amplfiers, as though a mega-bucks amp puts out some 'better' power somehow, than a cheaper alternative.

I did wonder about your loudspeakers, Jerry. They do look like they need a fair bit of power but then I recall you saying you had good results with a T-amp that can only deliver a couple of watts.