Amplifier selection for your Harbeths (general, not specific Harbeth models)

[David Schalkwyk]

I can understand your point, having just had a pair of Harbeths force me to reconsider what I considered good reproduction. But I have come round, painfully, to the conviction that you can't buy loudspeakers on the ground that they will hide the shortcomings of the rest of your system. What's the point? I've listened to the Spendor competitor of the Harbeths. Even with the problems that the HPL3s revealed in my amplifier/turntable/arm/cartridge (I'm not sure which), I wouldn't have bought the Spendors. That's not to say that the Spendors aren't fine for someone else. It just strikes me that if you don't buy a transducer that is designed to be as accurate (to the recording, not necessarily to the original event, because a loudspeaker doesn't know the original event) then you're going around in circles. I bought a pair of very expensive, very well-reviewed loudspeakers a couple of years ago that I thought matched the system I had. But I gradually became more and more irritated and dissatisfied with them until I could not listen to them any more. That's the danger of not buying equipment that is ruthlessly revealing. At least it doesn't lie. One can live with lies, but only for a certain amount of time.

Good luck, and best wishes,

David
.

[Bruce]

It just strikes me that if you don't buy a transducer that is designed to be as accurate (to the recording, not necessarily to the original event, because a loudspeaker doesn't know the original event) then you're going around in circles.

Well, that's where we differ. I want speakers that I can listen to for hours and just enjoy the music without constantly analyzing it to determine whether I have just the right components. What's the good of being accurate if you can't stand to listen to it.

[David Schalkwyk]

Well, that's where we differ. I want speakers that I can listen to for hours and just enjoy the music without constantly analyzing it to determine whether I have just the right components. What's the good of being accurate if you can't stand to listen to it.

Bruce, we could go on for ever. So I'll just make one brief remark. When I bought my previous 'speakers I thought exactly that: I just want to listen for hours (which I do). I don't believe that hi-fi can reproduce live sound with any kind of real accuracy. Problem is that when I listened for hours with my earlier 'speakers (which I bought following your principle--I've been there!) I gradually become less and less comfortable at what I was hearing. All I'm saying is that, to avoid future discomfort, buy the most accurate monitors you can (accurate as far as the recording is concerned). They may reveal problems with the ancillary equipment, but at least you'll know that. It's better than gradually discovering that what you thought would be pleasant, nice, comfortable, whatever, finally turns out to be irritating, deceptive, and unpleasant. That's all. Time is what counts here. I've made this mistake twice; I don't want to make it again. Our ears, as Alan says, are deceptive. But they're deceptive in a non-linear way. After a while, whatever they told you before, they'll rebel in the long run.

Will I be satisfied with Harbeth forever? I don't know. Maybe I'll grow out of love with them too. But for the moment they show me what has been missing for the past few years. There is no science to this aspect of the game. Alan has to hold on to science, but we just live our lives, trying to balance all the competing demands, including wanting to listen for hours.

Good night.

David

[John Parkyn]

Some recommend tube-based amps. Others, including - I believe - Alan himself, prefer solid state.

What's your opinion? What's your thinking?

=====

I am unsure whether proponents of each camp are referring to Harbeths in particular or speakers in general.

[David Schalkwyk]

I'm sure this was covered over and over in the old forum but I can't get into the old one and search. I'm considering the Super HL5 speakers. I have a PrimaLuna Prologue 2 K88T tube amp rated at 40 wpc. I don't have a local dealer where I can audition the SHL5's with my amp. I see a lot of posts in audio forums that say Harbeths need a lot of power and don't do well with tube amps. So I'm coming here to hopefully find out the truth from some real Harbeth owners. Is my PrimaLuna Prologue 2 tube amp adequate for the Harbeth SHL5's?

A quick PS to my last posting. It's perhaps extremely ironical for this discussion that one of the amplifiers I am considering as a match for the HPL3s is precisely the Primaluna Prologue 2! Perhaps you can tell me how they sound after your audition, Bruce?

Regards

And a final good night

David

[Miss j9]

Michell + SME+Shure+my modified 1959 Leak Stereo20 + Coffee Latte. Three choices of LS that I use; LS3/5a, B&W Nautilus (my own Xover design. Far superior to B&W! hehe) and Wilson Benesch Arc's. Would love a pair of Harbeth Monitor 30's but running out of room!

[Paris Kotsis]

It depends on your taste and speaker, of course. Monitor 40 won't be happy with a SET amp, but SHL5, C7 and M30 most probably will. I generally prefer tubes over solid state, for their tonal colors. Bear in mind, though, that much of these tonal colors are absent in most speakers but present in the RADIAL cone itself. So, maybe the best criterion is the speed of the amplifier which depends much on the amount of output power, amount/topology of feedback and class of operation.

[Philippe Monteyne]

My C7s are driven by a Woodside ISO 230 integrated valve amp, with whic I have been happy for 10 years... However, I recently decided to upgrade the system, starting with the source: Marantz SA11.... fantastic SA CD!

Regarding the amp, Woodside disappeared I guess, but my dealer in Belgium has still a possible amp/pre amp separate combination from Woodside which he suggests me (better bass etc...)

What do you all think ?? Any idea on the next level for a valve fan? The C7s are not the easiest loudspeakers to drive...

Cheers !

Just thought it might be interesting to see what members use to drive their Harbeths. I'm far frlom an audiophile or a techie but I imagine some of the following terms will crop up: solid state, tubes, integrated, receiver, amp, pre-amp.

Also please let us know what Harbeth model they're driving and watt power is at play (a wee joke there!).

Please let us know how satisfied you are with the resulting sound.

I don't have Harbeths yet, but currently (Lordy, another wee joke!) I use a vintage Marantz 2270 receiver to power Spendor S 3/5's and a Luxman receiver to push ADC (bet you never heard of them) sub and satellites. I am pleased with the sound these engines generate.

If I can improve the wording of the question let me know and I'll edit it.

[Bruce]

A quick PS to my last posting. It's perhaps extremely ironical for this discussion that one of the amplifiers I am considering as a match for the HPL3s is precisely the Primaluna Prologue 2! Perhaps you can tell me how they sound after your audition, Bruce?

Regards

And a final good night

David

I will. But, I will be auditioning the Monitor 30 and the C7's only, not the HLP3's. I would think that the synergy between the Prologue 2 and the C7's will carry over to the HLP3's. Don't expect any flowery reviewer type BS wordsmithing. I will be listening overall for whether I can live with this combination for long periods without fatigue (how the upper mids and treble sound) and how full the soundstage is at low listening levels. I'm looking for a set of speakers to keep for life where I can listen to the music and not constantly be listening for deficiencies in my components.

[David Schalkwyk]

[/QUOTE] I'm looking for a set of speakers to keep for life where I can listen to the music and not constantly be listening for deficiencies in my components.[/QUOTE]

Fair enough. I think I put it wrongly when I said that the Harbeths expose deficiencies in components. That was a bit too negative. What I should have said is that they're accurate enough to convey the musical strengths of any good component. That is to say, get an accurate loudspeaker, and you never have to replace it again, because it will live up to whatever you feed it with. And it will give you unending pleasure.

I've just had a fascinating evening. A friend brought a new amplifier he's just finished building, based on a John Linsley-Hood pure class-A SS design. We've spent four hours entranced by music--Bach Cello suites, Debussy piano music, Britten's War Requiem, Beethoven String Quartets; Arvo Part's Tabula Rasa; Dave Brubeck; Miles Davis; and Bill Evans. CD and LP--about half and half. The combination of the Harbeths and the Class-A ss was pure pleasure. I've never heard anything like it. Now, here's the interesting bit. Because he's having difficulty with temperature control, he's had to lmit the amplifier to 11 watts. Yes, eleven. With Britten's War Requiem. No sign of clipping; no strain.

I think I've solved my amplifier problem. Privided he can solve the temperature issue. I insist on at least 18 watts. Never know when you might need them.

David

PS He tells me that the amp is the ss equivalent of a SET amplifier. Now I know what they mean.

[Tony L]

I will be listening overall for whether I can live with this combination for long periods without fatigue (how the upper mids and treble sound) and how full the soundstage is at low listening levels.

If you can try and ensure the PrimaLuna you listen to is well burnt in - I’ve only had mine for a couple of weeks but the amount it has relaxed and opened up is quite pronounced. It sounded a bit edgy, mid forward and even a little harsh straight out of the box but is wonderfully open and clear now with no hardness or grain and is nicely tuneful, dynamic and punchy. It is a very good amp indeed and makes me want to keep listening to record after record.

Tony.

[Ted Rook]

"I see a lot of posts in audio forums that say Harbeths need a lot of power and don't do well with tube amps. So I'm coming here to hopefully find out the truth from some real Harbeth owners. Is my PrimaLuna Prologue 2 tube amp adequate for the Harbeth SHL5's?"


I use a 50Wpc TEAC Reference solid state integrated amp with my M30s with excellent results, including plenty of volume (loudness). Harbeth speakers typically give about 85dB with 1W input. So much of our quiet listening only uses a Watt or two.
Harbeth speakers present an easy load to solid state amps, that is the impedance does not dip lower than about 6 Ohms (except for M40) and the phase angle of the impedance is never more than about 45 degrees I think that is the figure, please correct me if I'm wrong.
Harbeths are intended to be driven using solid state amps which typically have very low output impedance (between 0.1 Ohm and 0.01 Ohm approx) and most users probably do use solid state, especially the professional users like the BBC who would not consider tube amplification to be satisfactory.

Most tube amplifiers have a high output impedance, typically several Ohms or more. The interaction of this with the load impedance of the speaker, and the changes of load impedance with frequency, mean that a tube amp though sounding pleasant is never accurate in the way a solid state amp with low impedance is accurate. If you like the tube sound that is fine, but they cause tonal imbalances that were not present when the speaker was designed using low output impedance solid state amps.

You can chose almost any solid state amp and get satisfactory low output impedance, they are all designed the same way, to provide a constant voltage drive to the speaker.

If you make tube amps and want to sell them to people you want them to use high efficiency speakers so the small wattage typical of tube amps produces usable sound levels. Harbeth's are in the middle efficiency range at 85dB with 1Watt at 1 meter. Speakers having 95dB efficiency get you 10dB more loudness for the same amp power.

In order to discourage people from buying speakers that work best with solid state amps the tube people invent negative ideas about them to make them seem unattractive. For example "needing a lot of power" what is a lot of power? 50W is not a lot of power in the solid state world but it is in tube world. 50W is all it takes to make Harbeths go really loud in my living room. In fact 20W is plenty most of the time. So "a lot of power" is only a lot in tube land not solid state land.

"Harbeths don't do well with tube amps" could mean a lot of things. First it is not true. The mutliple posts here reveal that many people are very happy with the combination of Harbeth and tube. Possibly the most useful thing that could be meant is to note that Harbeths, being intended for use with solid state amps, are average efficiency. In other words if you only have 9Watts from your tube amp your Harbeths are never going to be loud enough. But the same would be true of all 85dB efficient speakers, not just Harbeths.

Does that help?

Ted LS5/12A and M30

[A.S.]

"Harbeths are intended to be driven using solid state amps which typically have very low output impedance (between 0.1 Ohm and 0.01 Ohm approx) and most users probably do use solid state, especially the professional users like the BBC who would not consider tube amplification to be satisfactory.

Most tube amplifiers have a high output impedance, typically several Ohms or more. T ...

"Harbeths don't do well with tube amps" could mean a lot of things. First it is not true. The multiple posts here reveal that many people are very happy with the combination of Harbeth and tube....

First: I'm intrigued that tube amps has a high output impedance, which I assume is due to the windings of the output transformer? I'd be very interested to know if this is the general picture ...

Second: It's complete rubbish to believe that a) Harbeths are difficult to drive b) Harbeths are designed only for solid state amps c) Harbeths are not tube-friendly. All twaddle.

It is true that for the reasons I have consistently explained over the years, I do not personally use tube amps. I would welcome one, certainly at home, but I am obliged to use an amplifier that is maintenance-free and is just about guaranteed to perform the same across my entire working career. That seems to favour solid state. But I know from years of visiting shows and talking with customers that many Harbeths are paired with tubes - and excellent they sound too.

I keep a very careful eye on the electrical load that a Harbeth system presents to the amplifier during the design process. Many times I have rejected an otherwise excellent crossover network in favour of one presenting an easier load; hence the design time is greatly extended - perhaps by three times. It's very frustrating to abandon a circuit design that you've put many hours into solely because of the load implications, but its ultimately better than having customers on the phone all day seeking advice about amp/speaker recommendations - as if I was personally acquainted with every amp under the sun!

Other speaker designers may be less troubled by the 'universality' of their speaker load, but for me it is right at the top of the designers spec sheet. It has to be.

Overview of amps and power here: http://www.harbeth.co.uk/usergroup/showthread.php?t=41

[sevodude]

I think that perhaps one way to think of it is that normal cabling just add a lot of impurities or coloration, such that in the presence of a really good and pure conductor, you get to hear the sound as it is. So it doesn't really add, but rather, a good cable subtract less?
But sometimes coloration can be pleasing. Think about tubes, and we know that certain sonic characteristics like warmth and musicality has less to do with accuracy then euphony.

[Ted Rook]

I hope it was apparent in my post above that the negative material was quoted from other people's posts and that I was replying in defence of Harbeth. there is something about the construction of Alan's response which leads me to believe the quotes I made from others should have been more clearly identified as such. No big deal.

Yes, the high output impedance is a result of the output transformer. It is not universally true, there are some designs that incorporate the transformer in the amplifier's negative feedback loop and achieve solid state like performance figures.

Ted

[Ted Rook]

I fully support what Alan has said in reply to my post, Harbeth's have much to offer to owners of all types of amplifiers, solid state and tube.

Apologies for the misrepresentation which was unintended.

Ted

[A.S.]

I hope it was apparent in my post ... the quotes I made from others should have been more clearly identified as such. No big deal.

Ted

My reply was most definitely not directed at you Ted. It was abundantly clear to me that you were merely passing on hearsay.

I've heard the comments a couple of time about 'difficult load', 'not easy to drive' recently and on the surface it looks like a technical comment, but upon investigation, there is no basis to it at all. I suspect that, as average sensitivities of speakers generally have edged up (at the expense of sound quality) perfectly respectable mid-80dB sensitivities look, on paper, to be moderate. However, Watts have never been cheaper, sensitivity tells you nothing at all about sound quality and I value my hearing anyway.

I've tried to make clear that, as the designer, I am acutely conscious that Harbeths (with the exception of the three way M40 which is a special case) must be designed as an easy electrical load. And indeed they are. I just wish such commentators could see the extra strain that the need for an easy load creates in the design process. It really adds hugely to the mental effort because it closes-off so many circuit design approaches (which would result in very low or reactive impedances) and demand the highest ingenuity - right on the edge of your working knowledge.

[Ian Boyd]

As one considering Harbeth's, I'm sorry to hear that. I have an audition of the C7 and Monitor 30 set for this Sunday. So I will hear for myself.

Bruce, I have to say, I don't agree that Harbeths are difficult to match. Quite the opposite. I have owned HL-P3ES and HL-K6 in the past, and currently use Compact 7s. My experience is that Harbeths are the easiest speakers to match I've ever owned. I'm one of these people who holds on to old equipment, and I have to say I can use almost any equipment with my Harbeths (particularly C7s) and get excellent results. I attribute this to the fact that they have an accurate, natural balance across the frequency spectrum. If you use components that also give a reasonably balanced sound, you will get good results - and that doesn't necessarily mean expensive components. You can mess them up - but it's quite difficult, and needs components that have a strong 'character'. Anyway, you're hearing them tomorrow (I think) so you'll get a chance to make up your own mind. Hope you enjoy the demo!

Ian

[Philippe Monteyne]

Alan, I must confess I'm amongst the ones who said "not the easiest to drive" about the C7s. Actually, I should rather say that you don't easily obtain the maximum of what they can give you since these loudspeakers have so much to offer. What I'm currently experiencing is that you can dramatically upgrade the source etc.. and still hear the improvement, which demonstrates that the loudspeakers are not the limiting factor!

By the way, nobody replied about the WOODSIDE AMP... ?? Any good idea for me to upgrade the amplification, after having experience a few years with an integrated 30 W valve amp?

Thanks for any feedback
Philippe

[A.S.]

...I should rather say that you don't easily obtain the maximum of what they can give you since these loudspeakers have so much to offer. What I'm currently experiencing is that you can dramatically upgrade the source etc.. and still hear the improvement, which demonstrates that the loudspeakers are not the limiting factor!
Philippe

Now that is a completely different spin on the subject and one I entirely agree with!

"The better your source, the more revealing your Harbeths"