What tube amp for Harbeth 40.1

I’m not sure about the 40.1, but the newer models, the 40.2 Anniversary and 40.3 XD have an impedance curve that runs about 8 ohms and higher and rarely dips below that, so a pretty easy speaker to drive.  Your only question would be how loud you want it to go which is based on your room, listening position, music you listen to and your preferences.  

@yogiboy 

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

Hey yogiboy, good to know. Several colleagues with QS and others with Harbeths but not together. Which of the QS amps have you tried with Harbeth 40.1 or 40.2 speakers (if any) and and had good luck? And, stock or upgraded tubes used?  Thanks in advance for your reply. 

@decooney
I have the QS Silver 70 that I have used with the M30.1, C7 and P3esr. This is the amp that I have! BTW, I use KT88 type tubes!!
http://quicksilveraudio.com/wp-content/uploads/2017/07/Silver-70Manual.pdf

@yogiboy 
Very Nice! Goes to show good tube amps last and can be used with a variety of speakers.  Would love to try my QS Mono 120/KT150 tube amps with some Harbeth 40.2s to contrast and compare to my own custom built speakers.

Will keep my eye peeled for anyone who has paired QS with 40.1 or 40.2s, Thanks!  

I preferred Gold Lion KT 88's with my recently retired 40.1's, then moved to warmer RAM EL34's with my newly acquired, more neutral 40.2 Anni's.

@pdreher
Have you ever tried or considered a set of well matched Genelex Gold Lyon KT77s?

While I tried the same KT88s and EL34s as you in former amps I owned, several audio friends and members on this site have provided very positive feedback on the KT77s for a particular result and type of sound. Rarely do I see comments someone does not like them. Not as much kick as KT88 yet musical midrange like EL34s too; a blend of sorts, fwiw.  

@decooney 
I did try well matched RAM Gold Lion KT77's with my 40.1's and just found them to be "okay", as they lacked the bass of Gold Lion KT88's and the warmth of RAM EL34's.  Not my favorite tube for my application... but acknowledge synergy is key when it comes to matching tubes to tube amps and speakers.

@pdreher ...but acknowledge synergy is key when it comes to matching tubes to tube amps and speakers.

What amp(s) are you using? Are they stock or upgraded amplifier(s)?

The reason I ask is a buyer of my last EL34 (Triode/Ultralinear) amplifier paired it with his Harbeth 40.1s. He called me shocked about how much better it sounds than his former mono amps originally 2x the price of the amp he bought from me. Over a year of messing around, we eventually concluded the upgraded coupling caps inside truly brought the amps/tubes to an entirely new level. Test repeated with four other amps, thus achieving the same results. He's carried that same amp to several buddies homes, surprised at the difference upgrades make.

Now truly hearing each tube difference now, due to the internal upgrades alone. I was stuck years back on tube rotation with little difference. Other upgrades, caps, opened a whole new door of sound. A local 50-year tech mentor helped us a lot. Always appreciate wisdom and experience from those who paved the way... :) 

Or LTA z40 Ref mono
92 wpc
Circa 1960 EL34 Mullards EF2

Phenomenal tone balance. DEAD quiet

@decooney

The reason I ask is a buyer of my last EL34 (Triode/Ultralinear) amplifier paired it with his Harbeth 40.1s. He called me shocked about how much better it sounds than his former mono amps originally 2x the price of the amp he bought from me.

forgive me if i missed it down the line of posts, but what amp are you talking about?

@decooney 
I use a vintage Music Reference RM9 MK2 refurbished by Roger Modjeski in 2017.  It's been the best all around amp in my 20 years as an active audiophile.  

@jjss49
It was a former upgraded Cary V12R (tubes, caps, resistors, internal re-wiring in a few spots) paired with a fully upgraded SLP-98 preamp. Then Mundorf EVO Supreme SilverGold caps (2nd cap upgrade) brought it to another level. That amp inspired the same upgrades on other amps with similar results.

@pdreher
Very Nice. A good friend who passed a few years back had your same RM9 MKII version, always enjoyed the opportunity to listen to it. That amp was the one that pulled me away from ss/mosfet amps to over to tube.

Got to audition a VAC 170i integrated tube amp through a pair of Super HL 5+ 40th Anniversary model speakers. Sounded sublime. So clean, warm, but accurate, crystal clear. Not a particularly colored amp, maybe just a little? I was very impressed by it. I'd have bought it in a heartbeat if I was looking for a tube amp. Gorgeous sounding amp.

For a tube amp I’d take a serious look at VAC. Wonderful sounding amps. I heard one (170i) through a pair of Harbeth Super HL 5+ 40th Anniversary speakers. A match made in heaven.

It all depends on the type of sound you prefer: softer, warmer, less dynamic sound, or crisp, clear, dynamic sound.

If you like the sound of the JBL’s you noted, you’re not going to get that with any Harbeth driven by a tube amp. The closest you may get is with a tube hybrid like the MA252 or MA352 - which is not really a tube amp.

In fact, it’s even hard to obtain that sound with any Harbeth driven by SS amps.

The JBL’s have a "studio monitor" sound - more like ATC’s, Ocean Way’s, Proac’s.

The closest Harbeths get to that type of sound is with powerful, neutral SS amps like Bryston, Benchmark, ATI... or Hegel.

I have the M30.1’s and the M40.2’s - and - I wanted the same sound as you, having heard the JBL 4700’s - both crystal clear clarity and dynamics, but with a holographic sound - which is difficult to attain with Harbeths. I tried ARC Ref 5SE and ARC Ref 150SE in combo, and didn’t get close to that sound.

I then got the Hegel H590 - and "voila" - I now have it... or... as close as I’m going to get with Harbeths, which have a bit of a sound like they’re covered with a warm blanket - heavy on the bass and mids, with less clarity in the upper mids and highs - until they’re awakened with a powerful, neutral amp. Until I got the H590, I was ready to sell the Harbeths and move on.

Even with the H590, they don’t quite have the holographic sound of Maggies, or quite the crystal clear clarity and dynamics of JBL’s... but... they do have much of that sound... and... with a very rich, musical sound a lot like a live performance. In some respects, the crystal clear clarity of studio monitors and JBL’s is too pure for the sound of a live performance - by design to meet the requirements of studio engineers. The Harbeths, driven properly, have more of a live performance sound.

But... if you must try tubes... I’d try the MA352 hybrid, or the Atma-sphere OTL M60’s with AutoFormers, or the Zotl LTA - but, almost anything in your price range will disappoint you - given your stated preferences. You might try the combination of a tube DAC (the MHDT), a tube preamp, and a powerful, neutral SS amp - like a Bryston, or Parasound Halo.

But... in the end... given your preferences... I’ll bet you end up with something like the Hegal H300, H360, H390, or H590 - which is what Alan Shaw of Harbeth prefers, suggests and shows his speakers with.

That is... if... you keep your Harbeths.

Given your preferences - if you want to try tubes, you might find you prefer the sound of the Proac D2's driven by the Line Magnetic 518i, or similar.  That combination is closer to what you describe you prefer, especially in an apartment or condo - unless you're prepared to drive the Harbeths with a powerful SS amp.

excellent comments bassdude!

i keep my harbeths, proacs and atc's for exactly that lovely contrast in presentation

@bassdude
thank you very much for your comments.  Although I already bought a McIntosh 275, I always tempted to buy a SS with greater than 200wpc.  I have an old Adcom and it sounds quite good on the Harbeth.  Would there be any good (vintage) SS amp in $1500 range that you would recommend?  Such as old Luxman, Sansui, Onkyo ... etc?

The Harbeth 40.2, the Annie, and 40.3XD have slightly higher sensitivity than the 40.1, 86db vs. 84db, but those newer models have a much higher impedance curve. The curve on the 40.2 stays above 8 ohms throughout almost the entire frequency range even staying around 10-12 ohms which should make it an easier load to drive.  That's why tubes above 50 watts sound glorious. 

Just to give an update, after replying on 10/10, I acquired a 200W Sony TA-N77ES.  I need to take back my words.  Among the 8W 300B tube amp, 75W McIntosh 275, and this 200W Sony, I like Sony the most.  After listening for the Sony for a while, then switch to the 300B, some of them sounds good, but I feel something is lacking for many songs.  The 75W McIntosh is better, but feel a bit slow.  The Sony gives more dynamic.  Yes, the vocal is not as sweet, but it is not bad.  Maybe the Sony TA-N77ES is a warm sounding SS.

I am doing more testing last night and swap the IC. I only have two pairs of ICs. One I always feel bright and harsh, has been used between the preamp and power amp. I swapped it last night and it makes a HUGE difference to both MC275 and Adcom. But the improvement is bigger on MC275. For the 275, it becomes more musical and more airy. For the Adcom, it also sound more holographic, deeper sound stage, and less harsh.

Now, both sounds good, at least sound “right”. I need to do more listening. I still feel the SS is more dynamic. I feel I can hear more background instruments, while the 275 is more dominant by the vocal. I am also surprised how good the Adcom sound.

I just happened onto this thread and noticed the comments on the Adcom sound.

I may have stumbled onto something when I recently bought a current production Adcom 565SE. I have a tube pre amp and the sound can be quite remarkable with the Adcom. I was trying to understand why, I’ve put about 100 hours on it now, and the sound really is beyond what I was expecting. Non descript speakers too, relatively speaking. Infinity Primus P362(said to perform beyond their price point) while I wait for my Kefs to arrive.  I realize that Adcom doesn’t have the pedigree of the various boutique brands being talked about, but perhaps they still be at least somewhat competitive.

I should say I do have good cabling all around, and the midrange driver on the Infinitys is pretty good. I guess there really is something to be said for the tube pre/ss amp combination that some swear by in these forums.