I have Maggie MG 1.6's - need amp advice


I have Magnepan MG 1.6QR's and an Audio Research LS-8 PreAmp but only an Acurus A-200 power amp. I need to upgrade my amp to something twice as powerful I have been told (400 -500 watts) in order to really hear what the Maggies will do.
Since I have a tube preamp what would be a good SS Amp and should I go with MonoBloc's or . . .?
Tube? SS? Need help. I have heard that Classe amps are great with Maggie's. Any help would be appreciated.
Also of note - I have a Velodyne 18" powered sub (1250) watts for the sub.
johnrad
Dear Atmasphere,
Could you write a word or two about what you mean by "The trick with any tube amp is an effective 3-4 ohm capability...". Thanks.

Let's put it this way- tube amps in general do not perform as well on 4 ohms as they do on 8 or 16. Output transformers do not do as well on lower impedances due to increased turns ratios, which have inductive and capacitive effects that reduce bandwidth and absorb power.

OTOH, there are speakers out there that sound best with good tube amps and are 4 ohms. Maggies are an example. Not all tube amps with 4 ohm taps really work with the 4 ohm tap. For this reason, you are often better off with a set of ZEROs which are optimized for low impedances, while running the amplifier on a higher impedance tap.

In the old days Magnaplanar made some 8 ohm speakers which made the tube vs. transistor demo that much more profound. Going to 4 ohms has caused a lot of tube amps to cede some ground to solid state, but if the impedance issue is leveled, tubes easily win out. The ZERO is an easy access to this.
With Maggies you need alot of Power and most people think of that as watts, but in reality it is lots of CURRENT that gets Maggies to light up.
I had an older pair of modded MG 1 imp. ran them with a Bryston 3B 130 watts,an Adcom,a 300 watt Hafler, an older rebuilt B+K EX442 200 watts, afew different Rotel amps, a Threshold S/150 75 watts and a Forte Model #4(by Threshold) 50 watts class A.
Both the lower Powered Threshold + Forte amp smoked any of the other amps easily.
The reason why is the same reason that "Photon46" explained and it has to do with how the output stage is desiged, that really gets the current to the speakers.
It is lots of good current that will light up your Maggies not watts. Not saying go for low watts but don't be to concerned with really high watts, you want CURRENT!!
Check out Pass Labs for an amp, or some of Nelson Pass Threshold amps for a great used amp. Innersound that someone mentioned earlier works very well with Maggies.
Go for the current and if the watts come with it, that's great.
If you move up to the 3 series you then need lots of current but also lots of watts ( I also have MG 3a as well).
Biamping with an active X-over (line level) can really open up your world but like the other poster said it takes a bit of work the set it up properly, an off the shelf active X-cross over that works very well with Maggies + the 1.6 is a Marchand XM-44 (that's easy enough).
But I would focus on just getting a good amp first. Go over to the Plannar form on Audio Asylum (MUG) and there will be lots of info there and alot of folks that live + die Maggies to heip you.
Benie...I think you got it backwards. I would say "Go for the watts and the current will come with it".

Watts are Voltage times Current. Voltage is easy to make. A handheld battery powered device, like a Geiger counter can make and use thousands of volts. Current requires a heavy duty power supply. The current drawn by a speaker depends on its impedance and the voltage which you ask the amp to deliver. A 60 watt amp will deliver the same current as a 600 watt amp if the required voltage is 1 volt. At some higher voltage level either amp will be unable to deliver enough current to prevent the voltage from falling. When it falls enough to represent the spec'd distortion level the power at that point is the spec'd power. So, bottom line, power describes current capability.

Most solid state amps are power-limited by current. Tube amps, whose power supplies run at several hundred volts, may hit an output voltage ceiling, resulting in a flat top on a sinusoidal signal called (for obvious reasons) "clipping". Their distortion rises slowly with power until it takes a sharp knee upwards at clipping. Solid state amps do not have such a sharp knee distortion increase, and for them "clipping" is generally taken as the power level where the gradually-increasing distortion reaches one percent.

In the way of "full disclosure" I have used up to 600 watt amps with my MG1.6, even when supported by subwoofers, and I believe that "size matters".
Eldartford, this comment

Most solid state amps are power-limited by current. Tube amps, whose power supplies run at several hundred volts, may hit an output voltage ceiling, resulting in a flat top on a sinusoidal signal called (for obvious reasons) "clipping". Their distortion rises slowly with power until it takes a sharp knee upwards at clipping. Solid state amps do not have such a sharp knee distortion increase, and for them "clipping" is generally taken as the power level where the gradually-increasing distortion reaches one percent.

-is not correct. All amplifiers 'clip'. Solid state amps do so with odd orders, meaning that their clipping is harsher than that of tubes (and is one of the reasons that there is the story of tube 'power' being more effective than transistor 'power' as we have seen so often in other threads). It is true that with most transistor amps by the time they have reached 1% THD, they are clipping while this may not be true for some tube amps. There is a distinction here.

Beyond that you are right, power is power regardless of the amp that makes it, so if the amp makes the power that is demanded by the load and the output voltage than the current will be there too. Maggies are a fairly resistive load, so the 'current' that everyone speaks of cannot exist without the 'voltage' IOW: power.

"I canna change the laws of physics!" -Scotty
Atmasphere...OK: if you drive a ss amp hard enough it will clip. But (at least some that I have seen) the shape of the distortion vs power graph is characteristically different from tube amps. (However, I just checked the Hypex UcD digital amp module, and it does exhibit a sharp break like a tube amp, but then it is starting from way below 0.1 percent, so maybe it just looks dramatic. Perhaps it takes clipping to get distortion that high). As for the 1% distortion level occuring before clipping in a tube amp I think that this simply reflects the generally higher distortion levels of quite well regarded tube amps.

My ss amps have clip limiting. I doubt that I would approach their 600 watt rating, but if I did a gain reduction would prevent cliping, and its tweeter-damaging distortion. At lower power level the clip detection circuitry does nothing except listen to the signal so I don't think there is any adverse effect on the sound. Cheap tweeter insurance.