What tube amp for Harbeth 40.1

+1 on the VTA amps by Bob Latino. They offer striking improvements in clarity, soundstage, and dynamics to an already very good stock Dynaco circuit.

@bassdude 
Wait you haven't heard the speakers yourself with diff amps? 

@pdherer
Exactly listen to the OP! And I hated ATC as well. Grating and didn't think I could listen for hours. Magico is the same ol’ tower speaker I spent the last two months demo'img but overpriced nothing special IMO.

Having said that, I can also understand the response from Harbeth support.  They can’t just market their speaker to be good at only a limited type of music, they just can’t say that.  

Just to report back on my testing between a Custom built, 8W 300B amp vs McIntosh 275 IV.

I listen to soft Jazz music 95% of the time.  For those 95% with examples below, I don’t feel the McIntosh 275 is better.  Just an impression, I feel the 275 has greater density.  But the 300B is a small bit smoother, more relax, sweeter, have a easier listening, and more life like.  Not saying the 275 is bad, it is very good.  It has the 3D, holographic tube sound, just the 300B is a bit sweeter.
So Nicehttps://youtu.be/LKaAS3ZxiKM
Cry Me a Riverhttps://youtu.be/cizgXSegrko

However, for the music below, there is a big difference.  It is obvious that the 300B cannot produce the big bass.  I can imagine some symphony also need more power on Harbeth.  But at the same time, I feel this is not the type of music for Harbeth.  The same song play on JBL 4344 monitor with an 8W 300B can produce much better and bigger sound than the 75W MC275 on the Harbeth. 

My Grandma and Penghu Bay
https://youtu.be/zyylBQ3yUOs

But I don’t regret buying the McIntosh a bit, I always want a McIntosh.  It definitely sounds good for more music on Harbeth.  But instead of using huge SS amp on Harbeth to get the dynamics, I will just simply buy another speaker.  Why forcing a square into a round hole? ; )

It's all about personal preference.  I find I find Magico's to sound very nice, but ATC's to be loud and grating.  

Reading the original posters preferences for tubes and listening to jazz at moderate volumes, recommending high powered solid state amps is not in his best interest.

Just so you know... that is Harbeth Support speaking... not me.

They are the ones that say they only use SS amps to design, voice, test and market their speakers, because they sound better to the general public when driven by the types of amps they design their speakers with.

It may be that some folks prefer a more relaxed, warm, slow sound to the clarity, resolution and PRAT, that SS amps produce with Harbeths - which is my preference... more like the... incredible sound of ATC’s, Ocean Way's or Magico’s, etc. - though, Harbeth’s do not rival those with any type amp.

@bassdude

Makes perfect sense they would show their speakers with the mega watt amps in a public forum, BUT in a real world situation like your home where one MAY want something smooth, musical and warm, softer non fatiguing.... ALWAYS ALWAYS go for the sweet tubes of at least 50 watts at 8 ohms to meet what Alan has spec’ed himself as the minimum requirement. Now home theater solid state all the way!!!

I've used 3 solid state amps and 6 tube amps with in my 9 years of 40.1 ownership... and tube amps are my resounding preference.  But what do I know.

I have to agree with bassdude. I have owned the 40’s and currently the SHL5+ and tried Quicksilver V4’s, Quicksilver Mono 120’s, and had a long term loaner Audio Research Reference 75 SE Stereo Amplifier and none of them worked well with the Harbeth’s. I owned QS amps for years and they worked great with my Vandersteen's and I still love them.

My Harbeth’s sounded so much better with a Musical Fidelity Tri-Vista integrated amp, with the 40’s, and with the Aesthetix Mimas and the AX7e on the SHL5+. I just don’t think Harbeth’s and tubes mix. To me it sounds like someone threw a blanket over the speakers with any of the tube amps I tried. But this is my personal opinion and YMMV. We all have different listening preferences and only our own ears can tell us what we like. Also, Harbeth uses Quad SS amps to voice their speakers.

@aj523

What I’m saying is... very clearly... Harbeth shows their speakers with SS amps, and suggests you use a SS amp for the clearest sound from their speakers - you will often see them at shows driven by Hegel amps. And that has been my experience - they have greater clarity, resolution and dynamics with the SS amps I’ve heard them driven by. Their mids tend to be a bit muddy and overwhelming otherwise. Really...

Straight from "the Harbeth’s Mouth" in response to my inquiry of them as to whether tube amps could produce the best sound from Harbeths:

"That knowledge (tube vs solid state) cannot be condensed into a few lines other than to say that... ’Harbeth do not use tube amps at any stage in the design, listening or marketing process'... for the very sort of indeterminate interaction you mention..."

Regards,

"Harbeth Support"

I can’t be more clear than that...

I have a pair of vintage ARC Classic 120s that keep on impressing me each and every day.  I am not technical enough on speakers to choose an amp specifically for a single speaker.  I quickly looked up those and they appear to be 85 db sensitivity and 6 ohm.  My speakers are Platinum Audio Quattros with a similar freq response with an 86 db sensitivity and 8 ohm impedance.  80-85dbs are my range when listening loud.  These amps are amazing and so strong.  I have compared several solid state options up to 750wpc and none could match the volume nor dynamics of these ARC beauties.  I love having monoblocks so if you were willing to try something of this age you have these and the V140s which are very similar.  

If you want more modern I have been told that the ARC REF75 will also amaze and impress.  The reviews speak similarly that that piece is magical.  I haven't heard one but may try one day.  I wouldn't let the 75wpc discourage you.

Your best move is to a Bob Latino amp.  Either his 35 wpc ST-70 or the 
60 wpc ST-120.   The 125 watt M125 mono block amps would be serious
overkill for you unless you wanted to run them in 65 watt triode mode.  

The ST-120 is a Mac 275 killer.

You can get them fully assembled and tested as well as in kit form.  I personally love kits because I feel much more involved in the system, but most on this forum seem to buy their audio the same way they buy their luxury cars.

You see very few Bob Latino amps on the used market for a reason.   He's sold a ton of them, but people love 'em.  He also sells very affordable upgrade kits for the Dyna ST-70 and Mark III amps.

another vote for Quicksilver!

Yes,
McIntosh 6L6GC
Audio Note EL34 
Quicksilver 6BQ5 = EL84 

@jb505 

Aren't all those units tube based amplification?

My two cents...
I use a vintage restored McIntosh MC240 that sounded great with my Harbeth 40.1 (I no longer have). Looks awesome as well, it's definitely a showstopper when people come over.
My audio club friend drives his with an Audio Note Oto Signature SE. It sound fantastic as well and it's surprising what a low wattage amp can do.
With all that being said, I was on a trip to Southern California and visited a dealer down there who played me some Harbeths 40.1 driven by a Quicksilver integrated amp. I was floored, still am, by the sound that came out of those speakers. Now let it be said that his room was totally set for music like mine will never be but it was outstanding. 

Have used Prima Luna separates.  Everything said about them is spot on...

Ayon Triton III Integrated worked well with Harbeth SHL5 +, triode or pentode options.

@bassdude 

Hi bassdude, just so i understand are you saying that if a piece of music like the second jazz piece they played on Alan's 2015 YouTube video from this thread which hit a top transient peak of 30 watts will have more clarity, resolution and dynamics if the amp is a SS vs. a tube, both delivering those same 30 watts?  Really?  

Have both the 30.1’s and 40.2’s and agree with Harbeth, which always demo them with SS amps for optimum clarity, resolution and dynamics, especially with Hegel amps. They need a lot of something... watts, volts or current to clear them up and sound their best.

I like them with a tube preamp (ARC Ref 5SE with SS amps), which provides some of the qualities of both worlds.  They also seem to sound superb with the MacIntosh tube/SS hybrids.

Hi
Go for  AIR TIGHT ATM-2.
KT 88 tubes
80 W per channel.
Davud

go get an ARC VT100 mk3! works great on mine! My REF110 is not as good on the M40.1s. 

Read Allen Shaw's various essays on power requirements for the Harbeth 40 series. He advocates high power needs and presents demos to prove his point. I personally use Classe CAM 200 mono amps in conjunction with a Conrad Johnson tube preamp to drive my 40.1's and the sound is stupendous

My solution was to use a 300B Lampizator DAC to power a 500 watt Sanders SS amp =holographic tube magic with snappy transients and wide dynamics.

I watch that video, it is interesting.  But I have a question.  Is it really the speaker drawing power?  I don’t think the speakers draw power, but it is the amp pushing power, right?  
I have a question. if we play the same music, volume knob at the same level, to a more sensitive speaker, will it display that it is pushing the same 750W power? 

The amp makes the power and the speaker draws the power it can based on its impedance and the voltage that the amp makes. So for a given voltage, if the speaker draws one watt and its impedance is 8 ohms, into 4 ohms it will draw two watts if the amp is making the same voltage. Its a mathematical relationship.

Regarding the more sensitive speaker question, if the impedance is the same the power will be the same. Now the thing about more sensitive speakers is if the impedance is 8 ohms or more, the amp will not have to work as hard to make the same sound pressure level and usually will make less distortion. If it makes less distortion, it will sound smoother and more detailed (since distortion can mask low level detail). Now solid state amps in general tend to make higher ordered harmonic distortion compared to tubes, and so tend to sound bright, even though that distortion is fairly low. The reason we perceive it as bright is because the ear uses higher ordered harmonics to sense sound pressure and is thus keenly sensitive to their presence. It is this simple fact that is why tube amps are still around.


The reason solid state amps tend to sound bright is that usually they don't have *enough* feedback (some get around this by having none at all). Its pretty hard to design a circuit that allows for really high amounts of feedback (+35dB). So most simply don't. The result is that the application of the feedback itself, while suppressing some distortions, actually adds some of its own (which is almost entirely higher ordered harmonics; that which is not is IMD and both are very audible). Unless you can get over that 35-40dB range, this will be a problem, and its been a problem in solid state design since the inception of the transistor.


To get around this problem, many solid state amp manufacturers have resorted to a simple technique called 'lying'. But our ears don't lie- we've been hearing brightness and harshness in solid state amps for the last 60 years; that is why tubes and tube amps are still around decades on from being declared 'obsolete'.

I run the Leben 600x w my Devore 0/93.  Very nice combination.  PM me if you want to discuss the amp further.

Try some Manley💪

I stream a Cambridge Edge NQ through balanced cables to a McIntosh 275 into Harbeth 7-ES3 speakers and I am extremely happy with the result, as I age, my hearing has deteriorated so I can't analyse the result except to say it is the best music I have enjoyed in 50 years of Hi Fi / audio experience

@gte357s ,

’I don’t think the speakers draw power, but it is the amp pushing power, right?’


The speaker / amp relationship is pretty murky, at least to me, but the important thing to remember is that to get the same volume from the M40s a lesser powered amp might be forced into clipping, even if it’s for mere milliseconds.

Clipping happens when an amplifier runs out of power a bit like a car with a tiny engine going up a very steep hill. If there isn’t any protection built in to the amp, clipping can be disastrous for the loudspeaker.

With a more sensitive loudspeaker you certainly wouldn’t want to keep the volume knob in the same position unless you wanted to use it outdoors or in a much larger room.

This is assuming that it was capable of being played much louder in the first place. Not all more sensitive speakers are, but size is a good indicator.

It’s also worth remembering that loudspeakers are horribly inefficient devices. Hence the temperatures inside the voice coil can reach hundreds of degrees.

Much like car engines, most of the power going in is converted into heat. not sound (or in the case of the car engine, power). Overheating is a common enemy of both.

For those who like to play loud, thankfully before we are able to destroy our speakers by overheating, we should get a warning by experiencing a compression (and likely much distortion) in the sound.

It might simply not be worth going beyond a certain point of the amp volume dial as the speaker will tend to only get hotter, not louder.

https://en.m.wikipedia.org/wiki/Power_compression

https://www.psaudio.com/askpaul/do-amplifiers-push-or-pull-power/

I actually thought this would be more useful. But its semantics. 

I watch that video, it is interesting.  But I have a question.  Is it really the speaker drawing power?  I don’t think the speakers draw power, but it is the amp pushing power, right?  
I have a question. if we play the same music, volume knob at the same level, to a more sensitive speaker, will it display that it is pushing the same 750W power?  Of course, the music will be louder pushing the same amount of power to a more sensitive speaker.

On the other hand, What if using an amp with smaller power playing the same song, how will that look like ...

@aj523,

M40.2 Anniversaries?

Well, that’s certainly one impression of the current state of the art in loudspeaker design!

To be fair Alan Shaw has always stated that despite their seemingly low efficiency, Harbeth speakers do not present a difficult load to drive for any amplifier.


@gte357s,

Yes, keep us posted on how you get on.

The McIntosh MC 275 seems like another solid choice with first rate build quality.

A little more power can never be a bad thing.

@gte357s 

Definitely let us know. Hope this thread keeps going amd includes more user experiences....Harbeths with SS and/or Tube. 

Thanks for all the replies.  A lot of good suggestions.  I picked up a McIntosh MC275 IV yesterday.  The reason is that it is a local sale, the price is right, and it has a gain control.  I don’t have fund to buy a preamp now, so, this is a big plus.  I connect my source directly into it.  The McIntosh is more readily available in the used market also.  But definitely will try those other suggestions when something comes up.  I tried it briefly on my X5.  It is pretty good, but also don’t feel much special.  I will try it on Harbeth later today and report back.  

Any Harbeth that I have owned sounded great with Quicksilver amps!!
http://quicksilveraudio.com/amplifiers/

I'm running my Harbeth C7ES with an Aric Audio Transcend Push Pull amp with either KT88 or KT150 tubes(45 and 65watts).I also tried them with a pair of QuickSilver mid monos w/EL34,KT88,and KT150.The KT150s have the biggest liveliest sound,the 88s are good too.As expected,the EL34s run out of steam rather quickly.Personally,I prefer the tube amps over the 120 watt ss CJ amp I tried also.
IMHO the Harbeth 'house sound' puts you a few rows back as opposed to front row as far as dynamic swing and transients whether ss or tube.If I were in the market I would give one of the LTA amps a try.I have one of their preamps that I am extremely happy with.Just my two cents:-)

@cd318
That is a cool video! Interestingly when he actually played a recorded song as opposed to a test CD, the max power peaked at like 30 watts. So as they said you really have to take into account distance, listening levels, types of music you like to play and then match an amp to those personal characteristics.

Why should that rule out a carefully selected tube amp? Well...

Well yes on the HARBETH private forum (HUG), they humiliate anyone who wants to go tube. Basically the message is don’t need to spend a lot on amps, just buy the most watts you can even Class D over tubes. I bucked that trend and have the 40.2 Annies with the LTA z40 and it sounds glorious to me but what do I know...i listen with the grilles off, another big no no you will get ostracized over. Probably going to LTA Ref monoblocks which will get me almost 100 wpc at 6 ohms the minimum impedance.

No tube amp is likely to have the same dramatic bass punch as a powerful SS amp will. That's not why people buy tube amps.

These days most solid state amps have output impedances so low that they overdamp the loudspeaker; no speaker made needs more than 20:1 damping factor and many work better with less. An overdamped speaker exhibits a coloration that many call 'tight bass'. Yes, there is some punch but you really don't get much in the way of definition. Tight bass is something you hear in stereos quite a bit but its really hard to find in real life. In a nutshell in their zeal to create the perfect voltage source, amplifier designers far outstripped speaker designs in this regard!

A few reminders may be necessary before making the jump to tubes.

1 Alan Shaw himself is unlikely to recommend a tube amp.

@paulfolbrecht asked earlier,

'Have you seen the video where and where A. Shaw demonstrates that the big Harbeths easily pull 500W on transients?'

In that video Shaw himself was shocked at just how much current his M40 speakers were drawing on  certain transients. Yes, a peak of 750 watts!

[Not recommended viewing for anyone with low power tube and low efficiency speakers].

How Much Amplifier Power Do I Really Need?

https://youtu.be/Y3WpRY-EtX8



2 No tube amp is likely to have the same dramatic bass punch as a powerful SS amp will. That's not why people buy tube amps.


Having got that out of the way, if you still want a tube amp then I'd also suggest the Leben CS600. 

There are many accounts of satisfied owners using them with Harbeth speakers. See the Harbeth forum for more details.

Furthermore, the Leben amp is such a gorgeous work of art in itself that it should always bring you pleasure before you even switch it on.

If those Harbeth need power , Tsakadiris apollon mono willl work beautifully, they run my hungry power Andra speakers effortlessly,they are 150 watt. Few powerful amps I heard has the musical virtue like the Apollon.they are only 4K.

I have a PrimaLuna Evo 400 Integrated for the past three months. It is an incredible amp. 38w Triode and 70w Ultralinear. And if you need more power, you can roll tubes (KT88, KT120 and KT150) with the auto bias, no calibration required. I listen to 50's and 60's jazz and it is extremely sweet, detailed and creates a very special atmosphere.
I'm upgrading my whole system to Audionote (amp, speakers, dac, etc) so the amp is available if you are interested.

Try out the Vinni Rossi Lio
Excellent amp that will solve your problem

Tested on my Spatial Audio X5, the 8W one sounds more dynamic.

Naturally- SETs make distortion in such a way that the distortion sounds like 'dynamics' to our ears. But I get your point- we have a lot of Harbeth owners as customers and somehow they seem to work quite well together.

I also don’t think the power makes it flat or dull.  It is more depending on the circuit.  I have two 300B amp, one is 11W and one is 8W.  Tested on my Spatial Audio X5, the 8W one sounds more dynamic. 

Having heard the 40.2s with a 48 watt per channel integrated, I can attest to the fact that they were the exact opposite of "especially flat and dull".

Have you seen the video where and where A. Shaw demonstrates that the big Harbeths easily pull 500W on transients?

No offense, but you're cheating yourself using tubes of almost any power level with these speakers. They need lots of power, and are designed for a low-Zout amplifier.

These speakers, while having many great qualities, are not capable of anything close to lifelike dynamics even when given appropriate power. When they are not, they sound especially flat and dull.

Look for Tsakadiris tube amps, they are well made and very very musical , they have many accolades for audiophile that loves music,and emotions, I do own the Apollon monoblock, their stuff is very dynamic and versatile, they have 70 watt, mine are 150w using kt150, If you are looking for a tube amp, that will give you music and dynamics, this amp are the one ,they have different models, Toska audio here in Illinois carries them...my source for this amps SME 10 tt, Icon tube ps3, maRantz sacd, Schiit Gumby Dac, and Tellurium q cables...preamp Krell

I would look for used VTLs.  I sold a pair of MB-185s last year that would have fit your budget.  They would be a brilliant pairing and give you a little more oomph which the Harbeth's like.  

 But  ... it takes many tubes, it would add to the cost.  I am not sure how expensive are the tubes ...

@gte357s the power tubes are about 27.00 each. In a lot of cases a full set of them for our amps is less than one tube for some SETs!


You will need some power for this speaker. It appears to have a benign impedance curve but if the sensitivity number is real, a 60 watts will be a lot better than 20! A lot depends on how conservative Harbeth is about their numbers- As I recall they are pretty conservative so the speaker is probably easier to drive than the specs suggest.