This is funny. I haven't been on Agon in quite some time but stopped by here because I'm buying an Accuphase E-600 next week. Never in my wildest dreams did I ever think I'd make it to class A but I'm going for it. I'm looking forward to this next phase, especially since all my light bulbs are LED now!
Should I buy a Class A Amp.
I would Love to buy a Class A Amp. I have a Sony Tan-80ES Amp right now and I have had it for 19 yrs. To me it sounds Great but I am curious about Class A Amps. Do they really sound better? I am looking at a Krell KSA 200 Amp right now for $2000.00. It is older then my Sony. Is this too much for such an old Amp? Would Love to hear members thoughts on this.
Blessings, ..........Don.
Blessings, ..........Don.
100 responses Add your response
Get a pair of Usher R1.5 power amps and a Shindo Partager/Auriges or Mystere or Audio Research Preamp. I can vouch you’ll never look back. Before gunning for big money power amps listen to this pairing. The whole point is get a good very good Poweramp and a even better PreAmp. With a good power amp at one end the pre amp becomes your modular switch , a valve pre amp for your mood to sooth and ss when you want to rock. So wise up. |
Don, I cannot say what amp you'd like best. I don't believe anyone here can. My opinion is that the word "best" should be stricken from our audio hobby vocabulary. We simply have too many personal preferences about what pleases us most. And our systems/rooms are too diverse and matching can be a key element. So with that, let me offer a suggestion to look into, an amp that is not well known -- the Monarchy SE 100 Mk2. They are compact, reasonably light (monoblocs), affordable, and apparently satisfy customers with a wide variety of speakers, from Quads to large dynamic systems. |
| Post removed |
Many of the responses here are spot on. Ralph's are definitely spot on. And in no way was he touting his products over others. Amp design is formula based. Anyone that has taken amplifier design in college knows this. Design an amp that is nominal 100 wpc, drives typical 8 ohm loads, has input impedance of x and output impedance of Y, input sensitivity of z, operates at a frequency range from DC to light, etc. Pick the devices you want to use. Tube, solid stated, hybrid, BJT, FET, etc. Output impedance is a formula. Input impedance is a formula. Gain is a formula, frequency response is a formula, etc. Many people take other's designs and use them to build amps. They never did the calculations and detailed design work and therefore are unaware of those aspects of the actual design. A well designed amp is just that, a well designed amp. I'm not quite on board yet with Class D designed amps. But, I'm open to great Engineers/designers and maybe one day I'll demo one that is really nice. But, Class A, A/B, etc. Tube, solid state, this all depends on how good the designer, circuit topology, design, construction, and parts are.. My view is that even class A/B amps can really sing. Listen to a Mark Levinson 23.5 that is to spec and tell me that isn't one of the best amps that came out of that company. The power supplies have to be well done. If one has inefficient speakers, then lower power amps would have a really hard time driving them well. With efficient speakers and a decent room, 5 to 10 watts would almost drive you out of the room. So a good low power class A amp would be great. If I had more efficient speakers, I would grab a pair of Mark Levinson 20.6 amps in a minute. As mentioned previously, most class A/B amps are actually class A to a set power rating then convert to A/B status. So, a lot of people still confuse class A status. if the amp's output stages are always turned on, then that is class A period. The costs difference is typically based on a few things. 1. Power supply transformers, number of output drivers and lastly, heat sinks. Take a Mark Levinson 23.5 amp. With the power supply internal to that amp, two massive 1500 kVA (I believe) transformers, then only reason this isn't biased as full-on class A, is the costs of the necessary heat sinks. Which would be stupidly huge for full biased 250 wpc. Nelson Pass has an older write up/paper on power supply design and specifically discussed transformer and heat sink requirements. I believe it is on his DIY page. lots of really good reading there. but, does Class A amps sound better? Yes and no. depends on the design, speakers used, room, wiring, etc. Apples to apples comparison. Say your speakers sing with 100 wpc amps as recommended by the manufacturer. Say you pick an A/B amp and a Class A (fully biased) amp that can specifically drive your speakers. both solid state or both tubed. Both are within the same price point (important) and are well designed amps. I would bet you would have a really hard time hearing the difference at low power levels, because they both are probably operating Class A at that level anyway and at higher levels, you might, just might hear a slight difference. But I doubt it. Sorry for the long post, but this is fun. enjoy |
| Post removed |
My amp sounds better with some types of music than others.I would regard this statement as 100% correct and inviable- I can say exactly the same thing about my stereo. Some music is really well recorded and its going to sound better. I am also dead certain that I can find examples of recordings in genres that your amp does not seem to favor that would easily demonstrate that your amp can do fine with them too. Conversely, I'm also dead certain that I can find recordings in the genres your amp seems to favor that it would not do well with at all. What this comes down to is the recording itself and the taste of the listener. Some recordings are bright- bright amps likely won't work so well with that unless the listener prefers brightness (Harry Pearson of TAS had a tendency in that direction). Some are bass shy; boomy systems might work fine with that. Some have seemingly way too much bass (not sure how that could possibly happen but I play bass) and bass-shy systems might work fine with that. Along the way a person might become convinced that their equipment is favoring a certain genre but what is really happening is its favoring a coloration that happens to exist in a number of recording in their collection. Some of those colorations might be more common in certain genres- for example rock is often bright and maybe not the best bass, but that by no means says that all rock is poorly recorded! |
Hi Inna/Steakster, So you know, personally, I believe that you have the right to disagree with anyone, our hobby is quite subjective, Overall, I agree that one amp that is very flowing or smooth can sound different on a given system than a very detailed or analytical amp, which will give a different flavor on a small ensemble vs a large orchestra vs Jass or Rock.... One amp could have a terrific jazz quartet soundstage and a terrible soundstage on Orchestra, so I actually agree with Inna. My point is more... whether you agree or not, we don't need to be unfair with some statements... the quote that took me was this "Atmasphere's mythology is that there are no better amps than his and no better ideas than his. I'll leave him to that" I have overall found Ralph a gentleman and a great contributor... Actually the same with Inna, she is knowledgeable and has add a great contribution.... I really didn't want to start a rant or hurt any feelings... |
Don, since you enjoy the sound of your present amp,the important factor, I suggest that you keep it. Invest in improving your "sound" with front end upgrades, interconnects. "Isolation for your digital" could be eye-opening and give the best improvement for $$. Equitech and Furman websites provide info. I have been amazed by the improvements from clean AC. |
| Post removed |
Tim, As they say, just because I don't know how to cook doesn't mean that I don't know how to eat. If I hear the difference I hear it. Just because someone has ideas of what I should or should not hear doesn't change this. Ralph's tone is often egocentric and condescending, and I believe he knows it. I do not question the quality of his amps, by the way, I never did. But I will leave him alone from now on. So, yes, to state it again - I would not choose Kondo for jazz/rock and I would not choose Rowland, Pass or perhaps even Lamm hybrid for acoustic guitar music. I would choose tube amp. Which one? I don't know, I would listen to them all above certain level. But usually we have to choose just one, along with one pair of speakers, for many different types of music. My current amp is actually better for jazz/rock than acoustic guitar but not bad for anything. And speakers are the other way around ! However, it's a modest system by audiophile standards. Let's just not simplify and distort things. |
Hi Inna, I have to say that your postings are knowledgeable and opinions that seem to always be honest advice. I was a bit concerned with what you wrote about Ralph and his amps. I've read a couple hundred responses from Ralph and i've never heard him tout his products as the best or that his ideas are better than everyone else's. As you know and even Ralph knows, many people would step in and say that they've never heard anything better than an Atmosphere product, others would say that they don't care for it. The following comments are not directed to you, but are what made me write this: I am a speaker guy, I've been around building speakers for 35 plus years. No, I don't know everything, but there isn't a speaker conversation that I couldn't walk into, be at home and contribute too, yet, because I am no longer manufacturing or my name is not attached to a specific design, My comments are often overlooked or discounted as someone that just doesn't know. I personally know 2 different people that are guru's like Ralph that will no longer visit this forum because of the aggravation of constantly feeling like they have to prove themselves to others that just don't know...... With that, I would hate to lose Ralph and I appreciate Ralph and the few other pro's stepping in and offering real guidance. I don't mean to point this directly at you, I'm not trying to raise stink, but just felt that it needed to be said long before now. Tim |
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?Not really. The requirements of an amplifier do not vary according to the music. As I said before, the idea that an amplifier can be suited better for a certain type of music is a myth. From a designer's point of view there is no way to approach that. Even if you have a tiny SET power amp, if set up correctly it will not favor a certain form of music. You might find if its not set up correctly (the usual problem being that the loudspeaker lacks the efficiency needed to really allow the amp to sing) that it might seem to favor less dynamic material. But that would be simply because of power limitation and not because the music was classical or jazz as opposed to rock. Rock can be quiet and delicate too. The fact of the matter is people express taste in music and electronics do not as electronics don't have a brain and can't express taste like humans. when you get down to the slightly compromised amps there are trade-offs that mean some are better at rock than others. Bass and PRAT are essential for rock and some amps just don't deliver because they have other priorities.Bass and PRAT are essential for classical and jazz too- that is something universal. Now some amps have colorations- for example transistors can be bright. That does not help rock any more than it helps classical or jazz or folk. Tube amps can be overly rich. That does not help rock any more that it helps classical or jazz or folk. The only exception I can think of is actual instrument amplifiers like a Marshall or Fender, where the character of the amplifier becomes part of the 'sound' that a guitarist is trying to create (often with the assistance of effects pedals). As audiophiles we are simply playing recordings of such, so that really does not seem to apply here. This particular myth dies really hard BTW. But it is a myth! Amplifiers are designed with mathematical formulas which are not capable of expressing musical taste. If I can put this in perspective, someone asked on this website once if there was a speaker that favored mid1980s downtempo music. You might not really get what that might be (early Clan of Xymox?? Stuff on the 4AD label??); how in the heck are the electronics going to favor that over something a little more up tempo or recorded a few years earlier or later?? The answer obviously is they can't. In all cases you just get the best combination of electronics you can afford and hopefully it all is matched well enough that you can enjoy listening to it for some years. |
Atmasphere I've never heard one of your amps (I live in New Zealand) but from what I've read they would indeed do just as well on rock as on classical or jazz. Same with the big Pass amps. They're very expensive though, and when you get down to the slightly compromised amps there are trade-offs that mean some are better at rock than others. Bass and PRAT are essential for rock and some amps just don't deliver because they have other priorities. |
Ideally there should be no difference for an amp to play any kind of music equally well. In reality, there is. You don't want Kondo to play jazz/rock fusion. Some amps manage to strike a good compromise. But it's not only amps, it's also speakers etc. If I could I would have two completely different set-ups - one tube, the other either solid state or hybrid or also tube but different. Atmasphere's mythology is that there are no better amps than his and no better ideas than his. I'll leave him to that. |
| Post removed |
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? Actually, it was I who asked this question, and I had not ever heard this said before, myth or otherwise. Fact is, with my Pass XA30.5, that is exactly the impression I get. Better on some types of music than others. Relatively speaking. |
I am no rocket scientist here, but my suggestion would be fairly high-power A/B tube amps, 100 WPC, aided by a s/s Class D amp in each of the bottom end or sub-woofs, rolling off at about 100 Hz.. The Class Ds take all the heavy lifting away from the toobs, which can run quietly, coolly, and never leave Class A and can be run at fairly low bias. I defy anyone who says you need to run Class A all the way down to 30 Hz. All in, I'm only pulling about 6.8 amps from the wall. And that's only when I'm entertaining the entire neighbourhood. By all means, By all means, dedicate a circuit breaker of 20 amps and a manual-reset GFCI. I run a pair of Tylers at 4 ohms and have never blown a 3 amp fuse. Never had better sound, either. |
Hi don..you're probably overwhelmed with all the responses to your question. .I've been on the same journey with my audio gear..my first setup was a really old yamaha integrated with some phase tech speakers. .then I bought a old used onix amplifier and some rega ela loud speaker's. .I was interested in tube amps having grown up around them so I had the good fortune of doing a demo in my home for a week..the best way to buy audio gear in my opinion. I bought a used cary sli80. It sounds awesome and looks cool as hell..you can get a smoking deal on them and they are really versatile. .you can run many power tubes and run it in 40 or 80 watt mode,I rolled the capacitors in mine and wow what a difference. .that's my two cents. Best of luck! |
Hi Don I have owed a couple of KSA 200's and would have to admit I think the sound is great, but I have a slightly strange setup/situation a large room high ceiling thick stone walls and not very efficient loudspeakers (Linn Isobarik - passive) The problem with these amps is they are now getting on a bit, if you can find one in good useable condition it is likely to be expensive. I agree with some of the other views expressed that the ones worth having were the KSA series, if you have to go through a recapping procedure as I tried to, I found it difficult to find someone to supply the correct grade of capacitors and the cost of them alone was going to be over £1500.00 here in the UK plus labour and possibly other parts being required as well. I rather reluctantly at first replaced it with a Mark Levinson No. 532 Amp, this is not class A but I have been very pleased with it indeed. For me it does all that the Krell did and a lot more and has the added advantage that you are not generating the same amount of heat either, I was told that my KSA200 was sucking 2.2Kw of power when just turned on! The Levinson runs much much cooler I personally find the sound at least if not more powerful that the Krell but with even more detail, I just can't recommend it highly enough. If you want real grunt with great detail and a fine sound it's the way to go in my book! Matthew Lewis |
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. |
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 |
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 |
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. |
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 owned a KSA200 since 1990. Incredible amp. If your system is bass challenged look no further. No one builds amps like this anymore. In 26 years my amp only cost me $350 in repairs. I have paid more to repair an fpb mono with bad caps. Don't listen to the bs about a re-cap. If the unit was kept well vented you will be fine. If it was in a confined rack and could not breathe then that is a different story. If it is clean condition, and fins are black, that is a great price, for an amazing amp. Carefully check the condition of the amp you are buying. The fins turn more blue with heat and age. Make sure the color is consistent. Bring a thermometer and measure temp across all 6 cooling fins. This will tell if you have bias issues. If you do it is not the end of the world. The only issue with these amps and i have seen this on the 80, and the 160, is the small bias transistors used nylon screws to anchor to the internal heat sinks. Once the nylon fails due to heat, the transistor looses it's cool and you can get thermal runaway. Simple repair with a small stainless nut and bolt. Easy, cheap, assuming all else is good. After listening for 5 minutes you will wonder why you did not do this sooner Don't be afraid to pm me if you have any ?'s. Enjoy |
There's a downside of having a father who was an electronics engineer, building amps from age 12, and still designing and building them while training for four years as an electronics engineer.... Any amp, any class (a/ab/d) can be good or bad. Electronic components are inherently non-linear over differing temperature/voltage/current/speaker load conditions, and thus all an engineer can do is compensate for these non-linearities by using all sorts of different techniques. Class A's tend to be more linear because they reduce the number of non-linear variables in the equation. Friends of mine run 300Wpc Class A amps and frankly, they're probably the answer if you don't mind the heat and the power bill. Personally, when it comes to amplification, I don't subscribe to "let your ears choose" unless you promise to never say "my amp is better than yours". The technical purity of any amplifier can be measured. Perhaps start there, and then let your ears or wallet choose. |
Not all Class A amps sound good, but all of the best sounding amps I have owned have been Class A. I still run Classe DR3 VHC (105 lbs each, put out about 800 watts into heat when idling, and will drive anything out there (mine used to drive Apogee Scintillas which dropped to 0.7 ohms at some frequencies). I run a pair of them bridged and a single stereo version (running electrostats, which are good instruments to judge sound quality by) in different systems. I also run a Belles A, but have gone to Class AB for summer use (older Rowland amp) which also sounds very good and won't heat you out of the room. |
Here is something to ponder: You can't buy them, but Audire made both class A and Class A/B amps with the same basic parts. The A/B was twice the power, 200 vs 100 wpc (Parlando and Otez). Their designer, Julius Siksnius, an honest to god rocket scientist for the Apollo moon rockets, also had an earlier amp, the Forte, which used either bipolar or later, just to prove a point, a choice of the above or MosFets. He never claimed either was better. I have one of each. They sound the same. I have an Otez and a Parlando. They sound the same except on my best speakers, B&W 803's. On my Electrostatic's or older B&W's there is no difference. The 803's are my most efficient speakers, by far. The difference seems to be that the efficient speakers need less power and the Class A has it, so it has an easier life, despite the heat. I know that makes no sense, but I am not an electrical engineer. I like Pass designs, including Threshold, and Audio Research. Since Audio Research is available in older models, buy it if you can work on it for small repairs, like changing tubes (especially if you have a great A/C system) but get Threshold for total reliability if you are happy with transistors. Routine bias tweaks are less important on Classe A , as far as longevity. Tubes are good, but they age and you won't notice without something to compare them with. By then you have wasted a lot of time that could have been used to listen to great transistor amps that are much more reliable designs. |
I have a pair of Cary SLM D7 monoblocks. Pure class A. I love them, so yes. Like all gear beauty is in the ear of the listener and tube choice makes a big difference. I prefer to adjust sound with tubes and a preamp that has tone controls and eq switches. Used the pair cost only 1000 and kicks ass compared to anything I've ever owned. Yep, they are around 30 years old and still kickin. Go for it, class A rules. :-) |
i purchased a pass labs xa 30.8 when they came out and have been extraordinarily pleased with the amp. What made it really easy was the way reno hifi allowed a risk free demo. This was my first foray into separates as i had been a receiver fan, primarily with marantz, Rotel etc. The power for a small amp is there as i have not found any record that has overwhelmed it. From simple acoustic to complex jazz or classical, this amp rocks |
I was a Krell dealer and also a Musical Fidelity in the days when use to have big amps like the 270 and 370 which were class A. The ones I liked best were a pair of Stax 100 watt As through Quad 63s. I don't have any As now and find good ABs sound good are more flexible and far less trouble. I am using a CJ 350 and Gamut D200 which are not cheap but I got the Gamut for less than a good Class A |
Most Pass Labs amps are also high biased A/B amps, and yes if you were to play a piece of music that was very mellow like slow blues, some Class A/B amps may stay in Class A. But maybe with a full blown orchestra that same amp may go into class B. Also an A/B amp may stay in Class A if the speakers impedance stays at say 8ohms, but if that same speaker dips to 1,2,,3 or 4ohms somewhere in it's impedance curve then that same amp may go into class b. Cheers George |
