Phoenix Gold Xenon X100.2
First off, I would like to thank Errin Keeling, and Brett Howard from PG for hooking me up with an amp to test. These amps have been out for about a year now, and since no PG dealers exist in my area (I don't think they are in the whole state!), I could not go somewhere to look at one.
My belief is the "baby" amp in any amplifier lineup is the best judge of what the line can do. If the smallest amp won't measure up, chances are the biggest will fall even further short. PG delivered me a nice bundle of joy, the "baby" X100.2.
Since this review is mostly useless outside this forum, I am going break it up into three main parts, cosmetics, build, and performance. Cosmetics is not something I should dip into, as I probably don't fit the demographic this thing sells to, but this is my review, so deal with it!
Cosmetics:
One year ago when I saw Tad post pictures of these amps online, I nearly vomited. I will admit that. The amps looked way non PG, and more Star Trek. They sort of looked like a deep water air tanks, or manhole covers. Well, seeing one in person changes all that. The amp is still quite extreme, but it is very clean and simple in reality. Everyone I showed it to thought it looked good. It has clean lines, and the rubber ends are not like anything I expected. The finish on the aluminum has a nice industrial feel to it. The plating on the RCA jacks is clean, and goes with the rest of the amp. Fit and finish is great, all parts line up nicely. The amp has a very solid look to it in person. The rubber corner covers fit nicely. I wondered how these worked, and it seems they are a simple affair with a ridge which keeps them in place.
This is totally personal, but the top mounted controls are not so cool by me. I am sure I will be persecuted for saying that, as they are an installers dream, but my point is they look “tacky” when the amp is installed. I don’t want to see “Sens”, “Low Pass”, or any other audio jargon on the top of my amp. The only way in my mind to have top mounted controls is to put a removable cover over them.
The buttons on the x-over have a nice tactile feel to them, possibly nicer than those on a ZX series amp. The knobs are detented (about damn time PG), and are easy to set. They are all recessed into the amp, which is great, as they should never be “accidentally” adjusted.
The box deserves mention also. It is simple, and elegant. Nothing flashy. I am familiar with many of the older PG boxes, and this one beats them all. Even though the box has nothing to do with the amp once installed, for me a nice box gives me more perceived value. There is one issue with the box however. In the past few years, I have developed a knack for seeing a box, and knowing where it came from. Asian cardboard is much different than domestic cardboard. This box gives me the impression the amp came all the way from Asia in it. I assume this to be true. If PG wanted to give the amp an edge while sitting on a dealer shelf, domestic cardboard would be a step in the right direction. If you could care less what the box is, great, the next part will be more useful to you.
Build:
Some may say these amps are light, but this is a tank. Keep in mind there is no steel in this amp, so it will be lighter than a ZX or Ti amp. It is at least as heavy as an older RF amp (Punch 400.4), but this one has a fan, so it does not need as large a heat sink as it actually has.
The circuit board has a nice clean layout, and it is clear much planning went into its design. Welcome to the land of SMT, or Surface Mount Technology. If you don’t know what this means, grab a 1995 to current Rockford amp manual and see what they have to say about it. SMT is far more reliable than thru-hole plus it allows for many more parts in the same space, with greater precision of those parts. I an highly confident this amp is more reliable than my ZX amps for this simple fact. I do know PG had some issues with the first initial run, but assuming all that is resolved, there is no reason I can see as to why this amp won’t be running 10 years from now, or more.
Long gone are the days of the gold plated Phoenix Gold circuit boards, but this may actually be better as all but the solder joints are fully coated and insulated. This alone should cut back on some issues with loose wire strands inside the amplifier. I remember the gold boards on my ZX amps, and they did have a thin coating over the gold, but it was minimal, and easily scratched off.
The amp uses a very large transformer for its size, and it is wound in the same manner as any other PG transformer is. Standard dual inverse primary, with center tapped secondary, and extra pair of higher voltage very low current leads. The core is that of a MS series amp (MS2125, MS2250 and the like), so it is by all means not a slouch.
A second smaller transformer exists, and is of equally high quality. I have no clue what it is for, but it does not seem to be center tapped, or otherwise used for a (+), and (-) rail supply. (Note: PG informed me this is related to Xe.Load)
This amp has a total of 6 power supply switching MOSFETs. This is quite overbuilt for a 200W amp, to say the least. Based on some of my rough guestimates this supply itself is capable of well over 1000W. This being a Class A/B amplifier rated to do 200W RMS, it will never max out that supply, and during normal use the supply will just idle away.
For input "stiffening" capacitance, this amp has 12 470uF capacitors, for a total capacitance of 5640uF. This is a bit less than typical PG designs, but due to the use of many smaller caps, speed should be increased. This quantity is still way overkill, considering the rated power of the amplifier.
For rail stiffening, 6 1,000uF caps are used for a total of 3,000uF per rail. This is quite a bit weaker than a typical PG amp, but due to the overbuilt power supply, and the minimal power rating on this amp, I believe it to be more than adequate.
The amp uses one pair of rectification diodes, which is more than plenty for the demand of its outputs. These diodes rectify the output of the transformer into 34.7V (+) and 34.7V (-) rails.
The standard PG PWM controller for the power supply is used, just in SMT form, the SG3525A.
This amp uses another device I have never seen in a PG amp before, and that would be the use of voltage regulators. LM337, and LM317 to be specific. There are also two pairs of these devices. One set is for op-amp supply voltages in the preamp and crossover. The second set is for the voltage gain stages of the amplifier. These devices are not fixed like a common voltage regulator. They have variable regulation based on an input setting, and could theoretically be adjusted on the fly, hence my guess is they are a part of Xe.load.
As for output devices, this amp has plenty. 8 of them in all, and they are of the TO-3P package size. This is a bit smaller than the standard TO-3LP style BJTs used in earlier PG amps, so they should have slightly less thermal dissipation. Seeing how this amp uses twice the quantity it needs, I don't see any thermal issues ever occurring. (Note: PG informed me these are Sanken devices, and are made in Japan. They switch much faster than the traditional PG outputs, and are superior quality which is a bonus)
Local feedback resistors are quality ceramic types. This is as good as the days of the ZPA amps, which are the only other PG amps I know of to use these.
Bias pots look to be high quality, and solidly constructed.
Large buss bars are used throughout the amplifier. These bars are much beefier than those used in the ZX series.
Power and speaker blocks are solid, and easy to use. The have a nice quality feel to them, and are a welcome over the traditional PG barrier strip connections.
All heat producing elements are mounted directly to the anodized aluminum heatsink with additional aluminum clamps, and a thermal pad interface. Due to the nonconductive anodizing, I would have liked to see paste used instead of the pad, but this amp is so overbuilt, heat is not an issue anyway.
This amp has a single fan in the middle. I forgot to measure it, but I am guessing it is 60mm x 20mm. The fan is very loud when the amp “boots” up, but it quiets down to a tolerable level in a matter of seconds. (Note: PG informed me the fan requires full voltage initially to get it spinning, but once moving, it can be cut back, hence the louder starting mode) During my listening tests, the fan was nearly in my face, so it became annoying, but obviously in a trunk this would never be an issue. The fan draws air in through the top, and routes it down over the amps internal heatsink fins. The amp hardly became warm for any of my testing (which was not very abusive)
One of the most well thought out and built items on the whole amp, is the dreaded rubber ends most people don’t like. These have 4 steel inserts, a steel frame, metal inner decorative mesh grille, and the outer rubber shell itself.
Under the amps cowl, the power LED and its cabling is protected with a layer of foam. Towards the torroid is a rubber pad under the cowl. I am skeptical of the foam. It is the kind that rots over time. Since the fan is directly underneath it, I see the foam falling free in 5 years, and getting sucked into the fan which may amount to a series of failures. For all I know, this foam may be better, but I felt I should at least note this.
Lastly, I must note a feature useless to most, but appreciated by me. The crossover preamp board is in a plug in socket. This is very nice indeed. Instead of all the hassle of desoldering like with a ZX amp, this can be unplugged in the event of failure. Bonus points PG!
For the most part, this amp has the parts count, and “beef” of a ZX350. The ZX350 shares with it, 8 outputs, 6 power supply MOSFETs, 2 rectification diodes, fan cooling, and an onboard crossover with line outs. Keep in mind the ZX350 is rated to do twice the power of this amp, so that is a testament to just how overbuilt this amp is. Other PG amps using this many output devices are: M100, ZX500, Ti600.2, and Ti400.2. All of which are rated for much more power than this amp.
Performance:
First of all, this particular unit is an engineering sample. Although I believe it to be sonically representative of a production unit, it had other inconsistencies. PG told me it would have turn on and off pops. Well, this one had no turn on pop, but did have a terrible turn off pop. Also, when engaging the high pass filter while the amp was running, a major pop was experienced. This point is trivial, as once you set a crossover you usually don’t turn it on and off for fun. I am only noting this, as no ZX amp of mine has done it. The pop did not occur with the low pass filter.
For raw power measurements, the amp would do 23V unclipped per channel into a 4 ohm load, which is 132W per channel. This is more than rated, but less than the typical overkill output of a ZX amp. Keep in mind this amp costs less, and at least you get more than you pay for. With other amps out there, you often get just what you pay for, or less.
I bridged the amp and got to about 290W, prior to the power supply choking out on me. I am 99% confident I ran into the limitation of my power supply (40A), not the limit of the amp.
Now for a word about Xe.Load. I could not get it to work! For my tests, I use a 4” dual 2 ohm voice coil as a load. I should probably get a dummy load resistor to do this type of testing, but it is not too often I load an amp so I won’t invest the cash in it. I tried bridging the amp with the coil wired for 4 ohms, and still nothing limited the output voltage. I tried loading it 2 ohm bridged, and still nothing limited it. PG gave me all sorts of suggestions to get it to work, but the way I see it is if I can’t figure out how to make it do anything, the average user has no chance. My best guess is I can't correctly test it due to my power supply limitations. The fact that Xe.Load did not work for me is a good thing! I don’t personally like the Xe.Load implementation. The concept is sound, but I think PG went about it backwards. Everyone I know wants to get 2 ohm power out of their amp at 4 ohm loads. This amp has the beef of a Ti400.2 or ZX350. Both those amps can do at least 400W mono, more like 600W of dynamic ability. Why not make this Xenon amp do 250W x 2 into any load? Use Xe.Load to save the amp, not limit a powerful amp to be a tiny one. They way this works is like taking a Ti400.2, and fixing it to do only half of what it can. How many people would want to buy a “neutered” Ti400.2? This is just my opinion, so take it with a grain of salt. Xe.Load did not work for me on this amp, so I consider that a bonus, and am glad for it.
Frequency response was great. My reference amplifier is a M25. It is simply the best sounding, and best measuring amp I have come across. Mine is beat to death with all the paint falling off, but I still use it as a reference. These response plots done with my LMS show how the Xenon stacks up.
One gripe I have with PG I must mention, is to match the right and left channels. I know at worst channels are off by 1.5db, but when you make an amp with only one gain control, not one per channel, you limit anal fools like myself. The M25 is many years old now, and it manages to have matched channel levels to within fractions of a db. All my ZX amps were off in level, so here is a chance to make things even better, match those channels.
The results of my crossover analysis are shown in the following graphs.
The slope is steep, and crossover point is consistent between channels. I have no complaints with this.
Now for the question of sound. This is totally subjective, so I don’t feel anyone should add a lot of weight to what I say here, but it is your choice.
I hooked up the M25 and the X100.2 for an A/B test. You can see my setup below.
I must note I have listened to many PG amps. ZX, M, and MS. All of them sound the same at low levels. This makes perfect sense, as they all use the same basic design. The only differences between these amps are features and power levels. The M25 is a solid amp, with no onboard processing other than a bass boost, and it uses the bare minimum of parts, thus the bare minimum of inconsistency between parts.
A friend of mine who is really into audio also came over for his impressions too. I matched the gains of the amplifiers as close as possible with a DMM and a 1kHz tone. I used my DIY 8 ohm home speakers which have been measured to be a near flat response with very expensive test equipment, while I worked for Rockford. We played an assortment of CDs, mostly Rock, and Pop.
The results were as follows: We were consistently inconsistent, if you get what I am saying? This testing was done blind, with one of us running the switching, and the other listening. I picked one I liked better, then at a later time picked the other amp. He ended up doing the same. He was fully confident he knew one was better, but his choice changed randomly. This went on for well over an hour, and I developed a headache from trying so hard to hear any difference, there simply was none.
Bottom line: Xenon sounds as good as all the other top of the line PG amps do, and easily makes its rated power levels.
Final thoughts:
My guess is the big question is “Would I buy this amp?” The best answer I can give to that is “yes”, if a few changes were made.
First off, even though the amp looks nice on its own, it simply is not me, and won’t go with anything in my vehicle. If these exact same guts were in a solid square block of machined aluminum, I would be all over it. Industrial is me, and it is what I buy.
Next, I will blatantly say I won’t buy “this particular model”, as a 100W x 2 amp serves no purpose to me. (If it had my idea of Xe.Load, and was 250W x 2, I would really want one) My ideal setup would be a Xe100.4, and what ever mono amp matches it (Xe600.2?)
Which leads me to another point that is not directly related to this amp. PG, please put in a 180deg phase switch on the rear channels of your 4-channel amplifiers! I don’t care if it is a tiny internal jumper or jumper set, which needs to be moved to reverse the phase of the rear channels. My point with this is I want to use a 4-channel amp in “bridged stereo”, where I grab one lead from the front left, and the rear left to make a left channel, and do the same with the right. The business of external “Y” cables to get stereo out of a 4-channel amp is a pain. And on top of that, it kills the ability to use any other stereo onboard processing which may exist in the amp.
Lastly, Xe.load has to go. Even though I could not get it to do anything, the fear of it limiting me (someone who barely gets any power out of his amps anyway) worries me. I am not in full understanding of what Xe.load does anyway, so my feeling is it would be best if it dynamically reduced output. I believe it currently does that when thermal limits are reached, but it could also do it for output current limits.
If anyone reading this likes the looks of the Xenon, but doubts the performance, don’t! The performance is PG all the way. You might as well go buy one, as you won’t be disappointed. For those of you who trust the performance, but don’t care for the looks, join me in whining about it! Maybe with enough support, PG will change a few things, and all will be well.
Thanks for reading this drawn out review!