Matriix XT800, 1U Class A/B SS Amp review with modellers

[paulmapp8306]

Those looking to power a modeller, for use with a guitar cab. Theres a lot of debate about this, abd up lit now a valve power amp is/has been the best option. I use a VHT 2:50:2 Power amp because it gives all the valve dynamics the axe (or any modeller) will/should produce. Well thats fine but there blinking expensive and damn heavey !! So Ive been looking at alternatives (for 2 years !!) then found the Matrix XT800. A UK company with a long history. Well - Holy cow batman. 3.7KG, 250W per side into 8 Ohms (though I run it at -6db input sop around 62 Watts to my cab). Heres my posts from the Fractal Forum for those interested:


Matrix XT-800 Review, and v VHT 2:50:2 now with video
This will be spread over several posts I think. I will put some pics up when I get some taken - and will also do some video clips of both the Matrix and the VHT for comparrison (as best you can on the net).

Well, the new Matrix XT-800 arrived yesterday. First thoughts were, my god this suckers light. The pics on Matrix's Website make the amp look kind of grey and industrial looking which isnt to my tastes. In the flesh though, the amp is much darker, verging on black, and looks very smart. i took the lid off (Matrix have OK'd this though I cant take pics of the inside). Its very clean, and well build. solid solder joints and HUGH heat sinks. The cooling air flow is certainly well thought out, with the fans drawing the air directly through the sinks, and eddies in the airflow being created (on purpose) so no hot spots develope in the case. My only concern is the volume knobs are directly soldered onto the PCB - and are not bolted/screwed to the case. if you dropped the amp on the knobs there would be a lot of stress directly on the board. The pots threaded shank isnt long enough to allow them to be secured to the outer plate by nuts, and the PCB cant be moved closer to the pannel. I have suggested that a couple of U brackets are attaced to the inside of the facia, deep enough for the threaded portion of the pot to go through and locking nuts placed on both sides of the bracket. This would mean any iimpact would be taken by the bracket, and front facia rather than the solder joint and PCB. Matrix have never had any amps returned from damage caused this way, and the joint to the PCB is certainly solid, so maybe I'm being picky - however It would give be a bit more piece of mind.

My amp has been fitted with the Speakon/Jack combi outputs which is a bonus as I use stock guitar cabs so need that 1/4" jack output. Mine has also had the modification on the fans, so first up - how loud/quiet it the amp? Well it is noisier than the Axe, and from memory the Art too - but TBH I dont think its too much. Even at bedroom levels you cant really hear it over the guitar so? i followed DADAs lead and used a phone app to take some measurments (all at 1 meter).

Background noise: 25 db
Axe-FX (Silent fans as fitted by G66): 30db
Matrix XT-800: 35 db
VHT 2-50-2: 43 db

So, not as quiet as the Axe, but not as noisey as the VHT.

i havent had a lot of time to play yet, around 10 minutes at failrly loud volume followed by 20 minutes or so at bedroom levels. Firstly, I couldnt get the protection led to light at all !! while not a bad thing, it is how I tend to set the O/P (that is get a SS amp to clip slightly so I know its kicking out its max Watts, then back off the input signal so that its kickout out what I want for my speakers). Even with the Axe's OP clipping slightly the green Signal LED on the Matrix wasnt solid. Now according to Matrix the green LED is on at -10db to -8db and as I need 6db of headroom (to get the 250W from the Matrix down to the 60W my cab takes) Im probably about right even with everything on full. Ill try tonight with XLRs feeding the amp (currently use jacks) as that signal would be 6db hotter.

Initial thoughts on the sound is wow. Dynamically it is there. Reacts to the guitar just like my VHT. the clean was just lush. I then switched to the VHT, and there is a difference. Not much played clean however the VHT did seem a touch louder. As different amps have different input sensetivities I wasnt surprised TBH.

So - upped the gain and the differences betwen the amps start to show. the VHT had a deeper body on crunch sounds, and on high gain just seemed more satisfying. It had more punch in the gut, more thud/thump whatever, and also some sizzle in the high frequencies (the Matrix is clear and smooth). Unfortunately I ran out of "loud" time at this point as the wife and kids came home.

So - down went the volume. comparing the two amps now didnt show any difference in feel, but you could hear an EQ difference. the VHT having more bottom end, and bite. Now, this could be down to three things:

1. Signal level. As I said the Matrix seemed a touch quieter than the VHT with the same input. This will mean the amp sounds and reacts differntly (we know guitar just feels better the louder you go). if this is the case its no issue - just turn up the signal feed level.

2. EQ difference. This is to be expected. a SS amp "should" have a flat frequency response while the valve amp wont have. Again if this is the issue its not a problem, its just a case of tweeking the global EQ initially - and eventually re-tweeking patches for the new amp.

3. Valve mojo. it is possible that the extra body/punch/push whatever you want to call it is just down to valves (or more likely the speaker interaction with the output transformer on a valve amp). if this is the issue then theres no fix. You either put up with this difference for the size/weight/cost of the Matrix - or put up with thoses points for a valve amp.

So - I turned up the signal to the Matrix compared to the VHT by 2db. this certainly seemed to get them to the same kind of volume level. I also tweeked the global EQ. Basically adding 1db at 100hz and the same at 8khz. At quiet levels this made the two amps much closer. I may need to take out a little at 500hz maybe but I havent tried that yet. I have also not turned back up loud yet. Im hoping the EQ and signal strength will get the Matrix close. Certainly speaking to Mat at Matrix, the thump in the chest is normally around 90hz - so that could be the missing thing at volume. Im not 100% sure it will work yet, and it appeared (after the tweeks) that on clean sounds there was a touch more body to the sound on the Matrix - while on high gain the VHT had a touch more body. Im hoping that will be because of the patch EQs (in the amp block) otherwise the Matrix could be in trouble - that is if the cleans sound better on the Matrix but high gain on the VHT its not juts an EQ issue.

So - I need some more time to play, and particularly at high volume levels. The amp is certainly a good one. if I had no amp already Id probably pick up the Matrix over the VHT I think (due to cost/size/weight/reliability/servicing) - however as I already own the VHT its a harder call as to whether the Matrix will replace it at present. In a way that is a complement to the Matrix - the fact that Im considering replacing the VHT with this amp, and am prepared to work a little to get the two even closer. Its certainly better build, and sounds much better than the Art SLA (although thats from a year old memory of the one I had). I base that on the fact the VHT blew the Art away IMO, while the Matrix is giving me serious headaches making the choice. This amp is a real quality piece of equipment no doubt.

I will take some snaps when I get home, and work on the EQ when I can (around the kids/family). Ill also get some video clips done, of both the Matrix and VHTwith the same patches, both quiet (initially) and louder (when I can). ill also do a "switch on" of all 3 bits of kit (Axe, Matrix, VHT) so you get an idea of the fan noise levels. Any other thoughts I have, ill just add to this post so keep checking back if your interested in the amp.

[paulmapp8306]

OK. *done some investigation on specs and whatnot. *Firstly there is no way I could tell if both amps were kicking out the same power or not. *Heres why:

the Matrix has an input sensetivity of 1.2v. *thats +4dbu (well 1.23v is but its close enough). *That would give 250w into my 8 Ohm Cab. *So, so +1db would give 125W (half power point0, and -2db would give 62.5Watts. *So far so good. *

The VHT has two sensetivities, being 0db and -10db. *i actually had it set to -10db which would mean for the same 62Watts i would need to feed the XT800 an 8db hotter signal. *the most i pushed was 2db. *BUT, I didnt have the VHt up full !!. *id set it so by ear the loudest clean i use was just off breaking up. *So how much ws the VHT actually pushing out? *no idea.

The axe's max o/P is 18 dbu (thats at the XLR O/P - so 12dbu at the jack O/P). *So, *i pushed the Axes O/P full and increased the gain on the global out until the output started clipping (without amp attached) I then backed off 12 bd, so that should give a 0db. *i set the VHt to its 0db input and cranked it full. *So thats the VHt 60 Watts. *i then dropped the other global out to -2bd. *Thats the Matrix also pushing 60watts now.

so - we have a level playing field on signal strength. *HOLY COW !!! Thats MUCH better. *Still a little diffence in EQ but the feel was much closer. *i spent 30 mins or so playing with the EQs. *i used a clean, a High Gain and Scotts JCM800 patch for reference. *i ended up with +0.4db at 65hz, +0.3db at 125 hz, +0.1db at 4Khz, and +0.7db at 8Khz. *

my god. *i dont what to stop playing. *There is NO DIFFERENCE. *Well there may be a little but its so close. *i finally got the camera out before the kids came home, and the battery was nearly flat. *I got a quick demo done, but it is quick. *what i intend to do is whatever people want. *i can do shot clips of every patch/amp 9so one with clean and VHT, another with same clean and Matrix, another with crunch/VHt another Crunch/Matrix). *I could do 2 clips, one of the VHT going through patches and another with the Matrix going through the same patches. *finally i could do several clips each with one patch, but going between the two amps.

So who wants to see what? *Its more for you guys and which way is easier for you to compare the amps.

Anyway, pics and the short vid will be posted as soon as YouTube does its thing. *finally - no comments on the patches themselves please. *its not about whats a good sound or not - its more about comparing the two amps which can be done with a good OR a bad patch as long as their the same.

For me, Im taking a couple of days for the initial "holy cow) to ware off - but im 95% sure the VHT is on its way
out !!

Pics are done, video is uploading.







And here is the first video. *As I said short, noodling etc but it get the point I think. *others will follow if wanted.

http://www.youtube.com/watch?v=Djt-rh5wGes

[paulmapp8306]

I had the prescence and depth fully off for this comparrison. i do (or did) use them to roughly EQ a room, but i didnt think it was fair for this test. the Matrix is flat, and the VHT without any prescence or depth is also flat. because they are basically EQing the amp, you could always compensate in the global at venues.

The VHT was set to Class A/B. Firstly this is the most common mode of a valve amplifyer, and the Matrix is also class A/B. As for Saturation - you dont want any with the Axe-FX. Having said that, it was set up as described, to be given a 0db input, then cranked.


I spoke to Matt this evening and there have apparently been some enquiries. he said to let people know he has 20 XT800s ready to go, all with the modded fans - however they have Speakon outputs NOT the combined ones. Once these 20 have gone (and its not just us raving about this amp, so is the PA world), all future amps will have the Combi Speakon/Jack outputs.

anyway - heres another short clip. This one is powering up the Axe, Matrix and VHT so you can see how loud/quiet the units fans are.

http://www.youtube.com/watch?v=B5e6S_c9yO4

[paulmapp8306]

OK, another two clips. the first one is a Powerball sim, with mids down at 3.5, bass and trebble up a bit as is the prescence. thats it, nothing else. Its not my style so the tone may be meh - and my playing will be awfull. ive tried to palm mute as requested, but its not quick or tight. Hope you get what you wanted from it.

for both the clips the VHTs Prescence has been set as 9-10O'Clock as per the post stating this is a typical flat response.

http://www.youtube.com/watch?v=x8aEQV8yhUw


the second clip is a Blues clip. Ive got reverb on and played to a backing track. you get how the two amps sit in the mix a little (not really mixed, just played to). the track keeps playing and i switch between the Matrix and the VHT.

http://www.youtube.com/watch?v=JhDKKNrAcvU

[HillbillySims]

where can you buy one of these?

[Gasp100]

Wow, excellent review and I haven't even heard the clips yet! This is what the AxeFX (and modeling world or even POWER AMP users world) needs!.
A great, lightweight, powerful 1U solid state power amp at the FAIR price. Although, you haven't mentioned price yet.

[guitarnet70]

500 € here in EU, 680-ish US$

[paulmapp8306]

Yep. Currently available direct from Matrix (or one or two retail outlets in the UK). Available at £390 Stirling plus shipping (worldwide). That does make it pricey to the US and Ive Spoken to Mat about this. Thing is hes not sure how to do anything about it. Its what, Twice the Price of the Art SLA-2 in the US? Over here the Art retails at £300, so in the same ballpark as the Matrix for UK customers. In the EU its 370 Euro ish for the Art and 500 Euroish for the Matrix. Again much closer in price than in the US.

The biggest thing is it costs what it costs to make, and the £/$ doesnt help Matrix here. Add to that 20% VAT, which gets paid even if the Unit ships out of the country !!. If that VAT could be wiped off then a US price of $500 is achievable. Matrix are currently looking into ways - most likely a US build under licence.

The Unit has been tested in PA circles as well - who are also raving apparently. It was put up against an old Crown R1 (I believe that was the model) and apparently the Matrix gave the better performance. Having has the lid off my Old Art SLA, and off the Matrix - the Matrix is WAY better put together, and appears (from my Knowledge as an Electronics Tech - though Im no designer) to be a much better design too.

[Ben R]

Wow! It sounds good. That's nice tone - especially on the clip with you playing the Telecaster with the lower gain sound. It sounds pretty good to me.

I actually still have a 300 watt stereo Mosfet power amp that was made by Hafler and marketed by Digitech back in the mid to late 1990's. I pretty much always use my Axe FX Ultra direct (FRFR). But, the other day, I decided to try it with the cabinet sims turned off and running through the Hafler Power amp. I ran it into a traditional 4x12 cabinet and also into a 2x12 Mesa Road King cabinet (which has a partially open back on one side and is fully closed on the other side with a V-30 there). I ran it in stereo in each cabinet. I ran it mono in each cabinet. I ran it mono into each side (separately) of the Mesa 2x12 cabinet. In all cases, it sounded really good. I'm sure that these newer Mosfet power amp designs are even better than what I used that day.

I still prefer to go FRFR. But, it's nice to know that it sounds really good when used as a traditional guitar rig.

[paulmapp8306]

Indeed. i have tried both an old Haffler amp and some newer Lab Gruppens with the Axe, and they all sound good. Matrix actually have a crown R1, a Haffler, a Lab and a Bryson as reference amps. From the demos they've done to the PA world, the Matrix range is the best of the bunch.

Basically, a well designed, Class A/B Mosfet amp is what you need for audio. The Problem generally is heat, and the rail voltages. Matrix have managed to get the heat down, and a Rail seperation of over 200v. The rise time is greater than 0.65v per millisecond - which is why it sounds so dynamic.

[mxr2000]

What Cabinet and speaker did you use to test the Power amps with the Axe?

[octatonic]

Paul uses a Zilla 2x12 with a Vintage 30 and a H30.

[mxr2000]

so there is no Sims on this clips?

[paulmapp8306]

No. Power amp sims are on, Cab sims are Off.

[paulmapp8306]

This thread has developed somewhat on the Fractal forum - ill post the relevant bits here - basically my continuing thoughts with some from otheres who have tried the amp.