None of this shit has anything to do with the way an amplifier sounds into normal loads. If you are dumb enough to buy Wilsons then you deserve what you get. Ugly enclosures with crappy drivers and ridiculous cross overs.
Showing 16 responses by mijostyn
Oh, I would never run anything but a class A amp but I am not sure there is a huge difference between Mosfets and Bipolars having had both. I also run ESLs which are a totally different animal when it comes to drive so my opinion really does not apply to dynamic speakers. The systems I set up are all Planars except for the sub woofers another specialized animal. |
Oh and George, a 200 watt class A amplifier conceptualized by a Danish Graphic Arts guy and designed by teams of worker bees resulting in......? I would prefer the work a dedicated electronics engineer who puts his reputation on the line with each amp preferably American. I would never even look at a Gryphon. Too much invested in flash resulting in rather silly looking stuff. Sound and durability are all I am interested in spending money on. |
Why hasn't anybody spoken about Boulder amps. They are class A with sliding bias which for some unknown psychological reason I am uncomfortable with. Of course 250 large for a set of boat anchors is a bit steep even if your floor can support them. Next model down the 2150 at 100K is a direct competitor to the Pass Xs 300. Anybody ever hear a Boulder amp? Why would one buy it over the Pass?. |
What you will get running a Class A Pass amp into a 2 ohm load will be a very hot amp that will probably shut itself down or burn a hole through your floor. Into 4 ohms and up Pass class A amps will switch to AB at their rated power and continue on probably doubling that. God knows what the Xs 300 will do. IMHO there are very few speakers with impedance that drops below 2 ohms worth listening too. The amount of power any amp will put out is determined primarily by the size of the power supply. Whether or not the amp can safely transfer that power to the speakers depends on the capacity of the output stage and the size of the heat sinks. Power is power as far as I am concerned. I do not care about the type of output device used. It is all about topology and durability. I expect an amp like the $90,000 Xs 300 to run for a life time. If it can't I am not interested. |
I have not had a tube amp since 1969. I have blown a couple of SS amps, a Fuzz Linear and a Krell KMA 100. Tubes do have a major advantage in that they are easy to change. Transistors not so easy. I only care about what sounds better. If I have to change a tube once in a while that is no big deal. You settle on speakers and build the rest of the system around them. Since the Krells I have stuck with class A amps. They have a way of sounding more powerful than they actually are. Perhaps they handle transients better. The Atma-Spheres drew my attention because SoundLabs owners love them and they are for sure my next and probably last loudspeaker. The Atma-Sphere and Pass amps are the only amps in the running. Xs300s VS MA-3s. I seem to be always dreaming about the next system usually without regard to the price tag:) |
kosst I am not saying that Atma-spheres are the absolute best amp for those speakers but if someone were using a sub woofer and liked the other attributes of Ralph's amps. Why not? Damping factor is not everything. There are those (mostly Mcintosh owners) who say that a damping factor of 50 is more than enough. I certainly do not think that is the case with sub woofers. You can get damping factor way up there by cranking up the negative feedback resulting in a rather harsh sounding amp. Read this
http://www.soundstagenetwork.com/revequip/atmasphere_ma2iii_followup.htm My point is that although you can draw some good assumptions about how an amp will perform on a given loudspeaker you do not know for sure until you pair them up. I draw assumptions all the time but usually when I have overwhelming evidence. I am a SoundLabs fan. The MA-2 is the pet amp for SoundLabs users. These speakers have a rising impedance in the bass. I have heard figures up to 30 ohms. Perfect for these amps. I would also never have a system without a sub woofer array and I always use a very powerful SS amp with high damping to drive it usually a rather inexpensive commercial AB amp. Using an MA-2 for this would be rather silly from a cost and performance perspective. But, you can see why I have a strong interest in these amps. Atma-Sphere does push high impedance loudspeakers because his amps work better on them as you suggest and most people can only afford his smaller amps. High impedance does have it's advantages in terms of efficiency. Klipsch Heresys on stands with two sub woofers can put on a surprisingly good performance. Personally when I see Wilson Loudspeakers the first thing that pops into my head is R2D2. If I were to buy dynamic loudspeakers, which will never happen I would go for a large set of Magicos. |
Kosst I think Ralph would give you a huge argument on that one. It has to do with the relationship between sensitivity and efficiency which are not the same. Anyway, he says his amps drive low impedance loads just fine. He has several amps on Wilsons and the owners love them. The best way to buy an amp is to listen to it in your system which highlights the value of local outlets. We use to take amps to peoples houses all the time and leave them for up to a week. We would install them in the system and make sure all was OK then pick it up a week later. We would do the same with smaller speakers. Larger speakers you had to listen to at the store but we would hook up whatever electronics you wanted to the system. This was all by appointment. It is a travesty that most of these stores have failed. They had to become theater outlets for wealthy people but many of them were in areas where there were not many wealthy folks or the theater thing did not catch on in time to save them. But, you can't listen to an amp on the internet. Some manufacturers understanding this allow 30 day in home trials gambling that the customer will keep the amp. Ralph if you are listening I think you should build one of each model for in home trial purposes with a full deposit on the amp which will cut off people who are really not interested. Also make the customer responsible for return shipping. Granted tossing MA-3s around would be.........difficult. But, I think MA-2s would give them a solid idea of what they would get. People who are looking at the MA-3s are power hungry They won't settle for a measly 220 watts. That would be me:) That would make the decision to plop $147k on amps easier. I also have another idea. You should have customers with your amps in acceptable and presentable systems bird dog for you. Have people interested in your equipment make appointments with your "bird dogs" to listen to the amps. If they capture the customer give them a fixed fee for their involvement or a percentage of the sale. That might be cheaper than shipping amps all over the country. Just a thought. The Atma-Sphere mini dealer program:))) |
It all comes down to the way the amp sounds into a specific speaker and the only way to know that is to hook them up and have a listen. You can make assumptions all day long and many of them will prove right. But, assumptions are the mother of all f--k ups. A less expensive amp may sound just as good as a more expensive amp into a specific speaker and we are all price sensitive to one degree or another. |
The classic comparison is between Pass And Boulder Warm VS Dry, Tubish vs Transistorish. I am not totally sure about this but there is something about Class A bipolar amps which causes the designers to want to use fans and fancy bias tracking schemes. Do they generate more heat or require higher bias voltages. Pass seems to always avoid this but he does not run his power higher than 300 watts whereas Boulder will go much higher. JC simply switches over to AB which you can hear in the JC 1. Push it into steady AB and it loses its effortlessness. It still gets as hot on low impedance loads as a Pass amp. |