Newbie valve amp questions.

[tearinghairout]

Hi all
I have two questions about valve/tube amps, one quite general and the other more specific. Please feel free to answer one or the other or both.
TIA for your feedback.

1. What are your impressions of valve/tube amps generally? Do they sound 'better' than normal amps, or do people like them because they tend to look great and have a certain novelty/character value. I have known people who swear by them, and heard others say that they are not really any better than modern non-valve amps.

2. Has anybody had any experience with Markhill valve/tube amps? There is a Markhill MC-6L6A going on ebay (au) for what seems a reasonable price compared to other valve/tube amps. Are they any good? I realize that 'good' is subjective, so as a guide, how would you compare them to a Rotel RMB1066 or a Yamaha RX-V559 (apart from the number of channels).

Notes:
I am putting "valve/tube" because I am not sure of the correct terminology, and I wonder if in fact it is one of those "UK/US difference" things.
Despite that fact that my post count is 1 and I have dared to mention a brand by name, this is not a spam. I am simply watching an item on ebay, and doing due-diligence before bidding. I have deliberately not included any pictures of the amp mentioned in question 2, and also have not included any links to where you could buy said item.

[RGA]

I used to have SS and have heard much of the best of SS amplification.

Are Tubes better? Not always. The best amps I have heard are tube based and within the tube amps category SET amps I have found to sound the best. But they require High Efficiency loudspeakers - but IMO they also sound the best. The added bonus of SET is that they require no biasing, which makes it a plug and play unit when changing tubes.

My Audio Note amp and most from the company do not show the tubes and none of them look pretty in the least bit. So it's not about looks for serious audiophiles. Though there are sexy ones out there.

Don't know Markhill

Valve/tube - same to me. Makes no difference what you say. Usually you say valve amp and talk about tubes that you buy for the amp -- but people will understand either way.

[Mr Peabody]

There are generalizations that can be said of each technology and the sound is a matter of preference. Solid State will generally be faster and yield better bass control. There are tube amps that can do these well but they are expensive. Tube amps generally will give a unmatched presence, especially in the midrange. If you still like to Rock, I'd say look for a sweet solid state because one thing is a fact, tube power is expensive. The Class D & T amps are also gaining popularity because of running very cool and efficient, the sound quality of this technology is coming right along.

I would recommend not buying an amp you know nothing about. If you want tubes you should listen to a couple. Tube amps will vary from brand to brand as with any amp technology.

Speaking from my personal experience I had Krell amps for quite some time. Although the sound was very good, I still wasn't satisfied. After some listening and swapping around of gear I eventually went with a Conrad Johnson tube set up. I love the CJ it draws me into the performance more. The trade offs, nothing I've heard, SS or tube, has the transcient slam of my Krell. Kettle drums have a startling realism. The CJ offers more micro and macro dynamics and, of course, a presence I've not heard in any other technology. Then you have to know a little bit about the type of tubes an amp utilizes, EL34's are typically the warmest with bluming midrange.where KT88's and 6550's offer more power and better bass control, giving up a bit of the midrange magic. These types are found in ultralinear amps. The Single End Triode that RGA mentioned is another tube design with low power output. A cool thing about some of the entry level tube integrated amps is some of them offer a switchable feature from SET to ultralinear, the best of both tube worlds.

What price range are you looking at? If you want tubes, brands like PrimaLuna, Jolida or Cayin offer very nice performance at a budget price. Jolida has a hybrid, which is a mixture of tube and SS, in a integrated for around $550.00. I haven't heard this amp but it gets great reviews.

In my opinion Yamaha is not in the same range of performance as Rotel, and neither are solid states best representative.

As well as price point, what other equipment do you have?

[RGA]

TO add to Mr. Peabody..

The lower powered tubes and SETs need careful speaker matching. Not anything will do and the sensitivity rating is not as important as the impedance information. Most speakers have impedance dips in the bass and treble that are quite large and this is why "bass and treble" have been said to be weaknesses of SET amps and many PP tubes. But in reality these are not amp problems but mismatch problems. My amp is 8-10watts depending how you come up with the number and it has no problems at the frequency extremes but could on a speaker made from someone like a B&W.

Good tube amps cost a lot of money because their most important part is the transformer - few companies make top of the line transformers and many makers buy off the shelf transformers which can be suspect for specific applications.

Also be careful of which tubes the unit uses -- some tubes are very expensive some are cheap. I can replace all ten tubes in my unit for a $100.00 and my tubes are rated for 8 years. Some tubes like the EL 34 are rated for 3-5 years but they tend to cost $20.00. Still very cheap.

KT 88s can run $40.00 each and usually more. 300Bs can be $90.00 each or more.

[jrhymeammo]

Do you already have a tube preamp, or are you looking to go with a tube "receiver"? We get confused when some people use the word "amp". As RGA mentioned, it seems that tube amps have trouble with impedence dips rather than nominal impedence.

JRA

[jtgofish]

The best way to go is to use tube amps for midrange and treble [SETs are best] and transistor or digital for bass.

Of course your speakers need to be able to accomodate this.

Supratek makes preamps with dedicated circuitry for each[Supratek Cabernet Duo] and this is really the optimal approach.

That the rest of the Audio industry is yet to grasp this solution is bordering on the unbelievable.

[RGA]

You do not need digital for bass - what you need is properly designed efficient (which is not to be confused with just sensitivity) speakers and you will get all the bass you will ever likely need from a SET amplifier. Sets range from 1 watt to over 20 watts so it's not like you are seriously limited. 20 watts with reasonably sensitive speakers like mine will provide listeners down to 25hz and be enough to feel it in your chest and rattle the walls at loud levels. And my 10 watt amp will make you re-think the notion of watts equals bass or volume level.

You have to buy SET with a game plan and they are not going to be for everyone. HE speakers are often larger than average (well the ones with deep bass) save for some like Audio Note speakers, but they are not available for audition everywhere. Still an 8 watt Meishu 300B SET with the AN E LX provides deeper bass response at reasonable levels than say a Wilson Sophia or B&W N801 with Krell/Levonson mono-block combination. Though if you already owned the B&W or Wilson then yes you would want a powerful amp to drive the bass (and that would preclude the SETs. I have not heard hybrids that I have liked much.

[Mr Peabody]

RGA, I have not heard AN speakers or amps so I won't take a hard line but I think you may be stretching a bit when you claim lower or better bass response than Krell or Levinson, any of their separates. If it's true, then somebody ought to be demonstrating it from the mountain tops.

[jtgofish]

I love SETs but in absolute terms they simply cannot control woofers well because they have very low damping factors.Sensitivity of the woofers may help to a point but the basic electrical demands cannot be met sufficiently.There are a few SETS with high damping factors but they are extremely rare and expensive.

Push -pull valve amps have higher damping factors and do tend to have better bass but because they typically have considerable negative feedback they lack image precision and depth-which SETs do so well.

[Mr Peabody]

Conrad Johnson uses some negative feedback but they claim to use minimal. I'm impressed with the bass response of my CJ mono amps but it's definitely not as low and control as my Krell is. My amps use EL34's though and I understand 6550's can do better control. Driving my Dynaudio is a hefty task for a tube amp. They are fairly stable, just not sensitive and like the power. The CJ's have been up to the task.

[RGA]

Well yes if you are trying to drive difficult speakers like Dynaudio then of course SET does not have the "grip" in the bass.

All of that though is not the issue - What I said was that you need to buy a speaker that has the efficiency and the bass that complements the SET amps - not all SETs are of low power. Audio Note amps sound a lot more "powerful" for example than the same watt ratings from Cary SETs. A lot of it I suspect comes donw to the transformer and the only upper end SET maker making their own transformers is AN.

Take the N801 or Wilson Sophia with Krell or Levinson versus a speaker like the AN E and say the Meishu. The former system will play louder the latter system will play deeper and better. It's not just about the bass number - it's about the quality of bass when it comes out.

SS has an artificial "slam" while the Meishu presents a far more organic presentation in three dimensions. The SET doesn't get mushy in the bass. Don't mistake a lack of bass for the amp's fault -- it's the speaker not being efficient enough to be used with SETs. Answer is get rid of the speakers like the Dynaudio's and listen to speakers like the AN E or like.

Music is not about isolated events. Why would it be assumed that Krell or Levinson has better bass? More power? That is clearly not true and high damping factors = higher negative feedback which many feels = worse sound. So even if the Krell gets deeper bass and more slam it is using negative feedback to get which means it would sound worse. I would not trade quality bass for a bit more bass at louder level.

This fellow owned PMC and top Bryston kit and went to those silly SETs - read his review. Many shout from the mountaintops - just no one listens to it to confirm.

http://www.audioasylum.com/cgi/m.pl?forum=general&n=345133&review=1

[jtgofish]

Most tube amps have low damping factors.That is a fact.

It is extremely hard to achieve optimal peformance from any woofer with a low damping factor amplifier.
This is why McIntosh tube amplifiers have added autoformers[a type of transformer] that increase the impedence seen by the amplifier.

You can buy autoformers like those from Paul Speltz that go between the power amp and the speakers.These apparently vastly improve bass performance-especially from no negative feedback SETs.
6Moons recently reviewed these.
An interesting read.

[RGA]

Ok I'm not criticizing anyone who buys SET for the midrange and treble. Anyone who has done this IMV has obviously heard what SETs are capable of sound quality wise and already accepted the weaknesses of the SS amps they have heard. Most people who buy SETs have already heard the rather expensive SS counterparts like Krell/Levinson/Bryston/Classe or the like.

Yes measurably the SETs have lower damping factors - yes they dislike low impedance. And MOST speakers have huge impedance drops in the bass region(and in the treble for that matter). It has nothing to do with discussions on drivers of the speaker or the actual frequency being limited by the amps, because SETS are capable well under 20hz and way above 22khz. Where the problem lies is in impedance.

You need a speaker that does not dip low in the impedance and ALSO does not go super high. SETs are picky - they like relative consistency. As I noted the fellow with the 20,000.00British pound Bryston/massive PMC loudspeakers (and these have tremendous slam and deep bass) went to a simple SET based set-up with AN E loudspeakers. They were quite happy providing down to 25hz flat in Art Dudley's listening room with the SET amp and that is quite exceptional considering the speakers only have one 8 inch woofer and one 1 inch dome. (18hz-6db in room) The AN E only drops to around 4ohms and does not rise above 12ohm. It is very easy for a SET amp. SO now the amplifier does not need to work to produce bass because the speaker and corner loading are doing all the work.

The question is how much bass is really needed before it is considered deep bass. If a guy with $45K US worth of PMC and Bryston monoblocks is satisfied with the bass and the guy here in Vancouver who had Levinson and I massive chord speakers can go to 8 watts without losing and missing bass then one has to question some of these things in the industry that brainwash us.

Now having said all that -- of course if I had 2 ohm dipping speakers with 85db sensitivity then I would run SETs for everything except the bass and then some sort of big power amp that would not make the bass sound dead. I suppose I would look at a big tube power amp (maybe from McIntish) but only cause I like the big blue lights.:12:

[Feanor]

Hi all
I have two questions about valve/tube amps, one quite general and the other more specific. Please feel free to answer one or the other or both.
TIA for your feedback.

1. What are your impressions of valve/tube amps generally? Do they sound 'better' than normal amps, or do people like them because they tend to look great and have a certain novelty/character value. I have known people who swear by them, and heard others say that they are not really any better than modern non-valve amps.

...
Notes:
I am putting "valve/tube" because I am not sure of the correct terminology, and I wonder if in fact it is one of those "UK/US difference" things.
...

Tube, value, we know what you're talking about. :smile5: My perspective on tubes is likely not as highly informed as those of some around here, but I wouldn't buy a tube (value) power amp. The reason is my speakers, which I really like, need at least 100 watts per channel at 4 ohms. Realistically this excludes any tube power amp I could afford. The good new is my current power amps are of a high-bias, low feedback design and have none of the too-common solid state nasties.

A good chunk of the tube benefit, (smoothness, depth, "organic" quality), can be obtained from a tube preamp. I'm working with one of these at the moment and it's working out pretty well.

[Mr Peabody]

I have plenty of bass with my CJ. Some with an untrained ear may even say more. It's a different type of bass response. With CJ I do have bass detail, the notes of a bass line or other bass is well defined but the bass blumes more and not as fast and controlled as my Krell. When I play familiar CD's on the CJ and then the Krell, you can hear the Krell reproducing lower octave(s). Would the CJ play lower with more sensitive speakers, possibly. I'll have to see if the chance arises. I've actually been impressed with what the CJ, can do. The bass response is better than some solid state I've heard. But when you are talking Krell, Levinson or Bryston, these guys have bass down to a science and it would be quite a feat to have tubes come close with any combo of equipment.

It's very true as well the adjective "deep" when referring to bass may mean a variety of things to different people. I do get that the AN combo must have an impressive bass response. I'd love to hear the first track on Paula Cole's CD to see how it handles those bass octaves. Something like this is a good demo of what I'm talking about with Krell. This track with my Krell/Dyn's play extremely low and it's control is unreal. Krell's control is to the extreme though, I don't listen to Rap, but I've put some CD's into the system to see what happens. A CD that normally would boom. Playing through Krell you hear those octaves but there's no boom or flab. Your typical person probably would not appreciate this type of control or even perceive it as a lack of bass. The response is far from dead. You throw on something with a good stand up bass or something like Marcus Miller and you will hear lively.

[RGA]

I am not saying the Krell has "less" bass or the AN has more. I am saying the AN set-up doesn't lack bass. The sound of SS is typically more two dimensional and lean sounding which is certainly the case with Bryston. And I get that to many of those who have very little experience with tubes tend to find the leaness to be faster and tighter or I suppose more detailed.

I personally don't buy it based off of my auditions. I find that the analogy that the poster at AA used to be bang on. SS is analogous to florescent lights - it's light but it becomes fatiguing as opposed to natural light. The Meishu has a big round sound to it with the AN E which is very full rich and organic. So it will sound very different than the likes of a Bryston. Since most people listen to the likes of Bryston and most people buy amplifiers in the Bryston veign then it is highly possible for organic to seem slower. But over longer listening sessions the ear adjusts and you wonder how you could ever listen to Bryston like amps. But yes on brief listening sessions with pop recordings it may not wow. But most who go SET don't go back. Even some of the guys who went to digital amps and raved have gone back to SET. Having heard Bel Canto, PS Audio, and another maker my brain can't remember - the digital amps have some plusses - price being one - but even here they had some trouble with bass and drive compared to some SS beasts like Odyssey's and they don't have the organic sensation of the SETs I have heard.

I can't really speak to CJ as they are Push Pull designs and they really are a lot different than SETs. I heard CJ years ago and liked the one I heard a lot.

The fact that it can drive a Dynaudio to satisfaction is relatively impressive since Dynaudio is not geared to tube amplifiers. Someone here I think runs Dynaudio with Jolida 302b which is also surprising. That amp tends to sound tubey and does not have much power. But sound quality is better than sound quantity and after all music lives in the midrange.

[Feanor]

Even though I'm using tube preamp today and enjoying the smoothness, roundness, harmonic richness, depth, organic quality, blah yada, I can get past the feeling that these qualities are somehow an artifact.

When I first got my Sonic Frontiers preamp it sounded quite S/S; (it has that reputation). Wanting to find some of that vaunted tube quality, I started swapping tubes to see if I could find it. Indeed different tubes sounded subtly different, my current Amperx PQ's sound very fine and are delivering (in some measure) all of the tube qualities described above. Nevertheless having come off the neutrality of passive preamp, I can help but feel I've added ketchup to the plain burger of accurate sound. :p

[E-Stat]

This is why McIntosh tube amplifiers have added autoformers[a type of transformer] that increase the impedence seen by the amplifier.
That is correct, but is contrary to the issue at hand. Amps with higher damping factors have lower source impedance. OTOH, they generally have high enough DF to ensure minimal FR deviations. But not for every speaker.

rw

[E-Stat]

1. What are your impressions of valve/tube amps generally? Do they sound 'better' than normal amps...
This is a topic of great disagreement with no one "correct" answer. The reason is that tube amps are far more speaker dependent and the differences depend largely upon the type of music one favors. As for me, I have found a speaker that works well with tubes and find tubes deliver a more realistic presentation than the best SS I've heard on acoustical music and voice. The best SS, by comparison always sounds a bit lean and harmonically undernourished as compared with live unamplified music. With rock or pop music, the differences are less pronounced. With another one of my systems, however, I prefer solid state because of the speaker's needs. Points of reference: VTL Wotans, Conrad Johnson Premier One (oldie but goldie), Joule Electra Rite-of-Passage, ASR Emitter 2s, Krell KMA-160s, Edge Signature Monoblocks.

The issue has to do with their higher source impedance (thus lower damping factor). This is a highly misunderstood topic. While some woofers do require high DFs to control the back EMF, the larger question has to do with the interaction with a speaker and the resulting alteration to frequency response. If you have a typical multi-way dynamic speaker, chances are the impedance curve is all over the place. With high source impedance tube amps, their FR may vary significantly. Look at any stereophile speaker test using their "simulated test load". Fortunately, my main speakers have a far smoother profile and are not subject to that effect.


I wonder if in fact it is one of those "UK/US difference" things.Yes. We say bathroom. They say loo. We say apartment. They say flat. We say trunk. They say boot. It's the Queen's english!

Sorry, I am not familiar with the brand mentioned. I would start by looking at your chosen speaker to determine what works best with it.

rw

[Mr Peabody]

E-stat, what are your impressions of Edge? I've heard they take SS to a new level, as far as sound quality. How would you compare them to Krell?

I heard a pair of VTL monoblocks and was impressed. I thought they had great bass. A friend of mine thought the bass was fat, but I didn't get that impression. I guess it depends on what your reference is.

[E-Stat]

E-stat, what are your impressions of Edge? I've heard they take SS to a new level, as far as sound quality. How would you compare them to Krell?
To be fair, I've only heard one Krell and that on woofers only where it did quite well. On the other hand, I've spent a fair amount of time with Signature monoblocks in a two channel arrangement and a five channel model in a MC system. They are superbly clear and focused. It is the midrange where I find tubes usually have the advantage. The Signatures do a better job at that than any other SS amp I've heard, save perhaps the ASR Emitters which preclude the need for a preamp. I must also confess a certain lust for the looks of the Edge given my aesthetic priorities. They are simply gorgeous. Every panel is machined aluminum and attaches snugly to its neighbor using countersunk machine bolts. It has an elegant simplicity.

http://home.cablelynx.com/~rhw/audio/edge.jpg
http://home.cablelynx.com/~rhw/audio/edgerear.jpg

I would truly like to hear the Krell pre/power amp combo Tony Cordesman found so vexing. They could well meet or exceed the Edge amps. I met Dan D'Agostino back in the 70s at the hi-fi shop where I worked part time. He was then the rep for Dayton-Wright electrostats and Dunlap-Clark amplifers, massive beasts that could handle the evil load of the D-Ws. Come to think of it, they had the a similar fanned looking heat sink design found in many later Krells.


I heard a pair of VTL monoblocks and was impressed. I thought they had great bass. A friend of mine thought the bass was fat, but I didn't get that impression. I guess it depends on what your reference is.
That could be a fair assessment depending upon the speaker. Using them to drive my double Advents yields a somewhat sloppy, fat bass as compared with a Threshold. While the stats are a bear of a load in certain respects, they have a fairly tame impedance profile and don't take on that character with them. They are superb at rendering the timbral accuracy of the large concert drums for example. BTW, those are Wotans sitting behind the Edges. :). Those gentle giants redefine the term "authority" as I was first introduced to that concept by the C-J Premier One back in 1980. Power and grace. Both in generous helpings.

rw