Should I buy a Class A Amp.
I agree. That Krell looks like the ticket. Get one second hand, get an electronics guy to give it the once over - aka http://theartofsound.net/forum/showthread.php?27792-Krell-KSA-200-for-sale-Complete-nut-and-bolt-rebuild you'd have a sweet amp |
I have a couple of sliding bias class A amps, a Threshold 400a and a Bedini BA-803. They were used to power a pair of Acoustat 2+2. The Threshold 400a sounded good but was a little light on the bass. The Bedini BA-803 sounded a little better and the Acoustats had stronger bass response using it. The Bedini has 200w/ch vs 100 w/ch from the Threshold. I do have a pure class A amp that is currently out for repairs, a Bedini 100/100 1 meg. It sounded the most natural and had amazing bass output with the Acoustats and other speakers. It is also a fast amplifier and uses positive feedback. It is 100w/ch but sounds more powerful than the other two. It did run hot though. For the summer time for general use I run a Jeff Rowland model 5 class A/AB amp. It runs cool and can handle the Acoustats well. It has a detailed yet laid back sound. Bass is there but not as deep. Tube amps can also sound very nice with electrostatic speakers as I have a pair of Ray Lumley M100 tube mono blocks using KT-120 tubes. Again a full, natural sound with strong bass but not as deep or controlled. Soundstaging is the best with the tube amps, wide and deep with instruments in their proper locations (imaging). The tube amps are push/pull class A/AB. So which is best? Like has been said, it all depends on what you are looking for. Overall for me it is a toss up between my Bedini 100/100 1 meg class A amp and my Ray Lumley M100 tube mono blocks. |
Don't count out the Luxman Class A amps new ones and some of the older ones. I run an L560 50wc pure class A from 1986 (updated version of the L550/540)and its rather nice for a 20 year old amp. utilizes a heat pipe i.e. liquid cooled, idling current is set at 160mV for each channel so it runs very hot and pure class A all the way. Replaced some AudioNote gear and not looking back. I've also heard the New versions the 25wc and the 35wc and they are very nice (I liked them better then the new pass stuff) Little expensive but worth a look if you can find a used one and build like tanks. I'm driving some Living Voice Avatar 2's with really good results http://www.thevintageknob.org/luxman-L-560.html |
There are lots of different class A circuit designs, but you can't go wrong with FirstWatt amps by Nelson Pass, if you have fairly efficient speakers. Reno HiFi will let you try before you buy too so you can hear it in your system. My F7 runs really hot, especially this summer on the east coast! But it is worth it, drives my 88db speakers very well and has a lot of the holographic qualities associated with tubes. Enjoy! Ron |
Could it be said that Class A amps, like Pass for example, play better on certain types of music? Better classical than rock, for instance? No. Class A circuits simply have less distortion due primarily to the fact that there is zero cross-over distortion that is found in A/B amplifiers. A less distorted signal should sound better for all music types, unless you prefer that sort of thing - which many do in the tube world. There is no right answer, but from a physics/electical engineering standpoint a Class-A amplifier is a "better" design when it comes to distortion. |
