XTZ Class A100D3 Amplifier - partial report

[Macca]

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]

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]

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.



Astonishingly good value.

[Macca]

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

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]

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]

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.



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. 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]

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

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 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/showt...ight=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 ), 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]

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).



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]

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 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

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 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

[Macca]

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.