[mresseguie]

I finally did something I've often thought of doing. I took my SS SimAudio i3.3 integrated amp into an audio shop yesterday and compared it to a tube amp/tube preamp. In this case the amp was a McIntosh MC275 version 6; I've forgotten the model number for the preamp, but it was also McIntosh and it was tube. The speakers were Sonus Faber Olympica I stand mount speakers.

We first played several songs with the i3.3 amp to get a feel for it. This amp had grown cold, so its sound changed as it warmed up. To be honest, it probably needed another 20 minutes to really warm up, but it was close enough for me. Then, we hooked up the McIntosh amp/preamp and played the same songs.

HOLY Shnikies! The difference was huge. I looked at the guy and said these are different speakers now. I had no idea there would be this big a difference in sound. In another thread on AC I asked about the 'McIntosh sound", but at that time I hadn't compared amps like yesterday. Now I know.

I was very impressed--not just impressed.....I loved the sound!

Now I want to know/understand what other brands of tube amps/preamps sound like. I know about a half-dozen brands (AVA tube amp/FET valve amp, Roger Modjeski's amps, Bottle head, and a few others). Do other tube amps sound similar to the McIntosh amps, or does each brand have its own flavor/sound?

Should I seek out as many different amps as possible, or should I just jump in and blow $5500 on the MC275? Oh, I know 10 people can reply with 10 different answers. That's cool. I want input, so the more the merrier as far as I'm concerned.

Anyone?

[Docere]

I have caught up with friends, had a few drinks... and may not be int he ideal condition to help...

For me, there are different approaches or paradigms. Each paradigm sounds different to the other and systems within them sound more similar, but differences persist - there are more or less impressive examples of each. Solid state driving weak, high Q, low efficiency speakers have general types of sound. Push-pull tubes with high negative feedback have a similar sound, but enough differences exist to have folks preferring them over solid state. Then there are the tube amps with zero negative feedback powering appropriate speakers, which IME are significantly different to others - but these systems polarise opinion.

The challenge is in finding the amp-speaker combination that has the virtues you value, yet avoids the issues that become wearing over time. You may need to identify what traits in music an its reproduction move you... or simply, what type of system does it for you. For me, single-ended triode (SET) amps driving high efficiency, over-damped speakers are where it is at. If you are liking the tubed Mac, maybe seek out a quality SET amp with copacetic speakers: you may not like it, but then you may think you have never heard music reproduced with so much expression. But hey, I am speaking from the heart, not he head, so take this advice with a grain of salt!

Okay, that is just some off-the-cuff random thoughts - I may think differently tomorrow.

Cheers,
Ray

[Guy 13]

Hi Michael.
Next time you go to Asia, on your way to Taiwan, why don't you make a little detour and come to see me, well, maybe not me, but my system.
Of course that is, if you have to pull the trigger on the tube McIntosh.
I think you will like the SET amplifier with hi-efficiency extended range driver.
I think you already have the Rythmik servo sealed sub-woofer(s) I have the same,
I would be more than happy to make a set up for you.
Anyway, I don't want to be negative, but I don't think this will happen,
but wanted to offer my help on your more or less decision.

Guy 13
 

[borism]

I used to own a McIntosh MC 275-V (loved it with Thiel 2.4 speakers and preferred to a BAT solid state amp) and after I changed speakers to the AudioKinesis Jazz Modules (efficiency: 92) and compared the Mac to an Atma-Sphere S30 (OTL) I definitely preferred the Atma-Sphere in that combination. I think it is always the amplifier - speaker combination that counts and has to be synergistic.

[mresseguie]

Thanks, guys.

Your comments pretty much back up what I'd guessed. I need to do some driving and listening/comparing. I need to borrow amps to take home to find out which one sounds the best. And I need to figure out which one gives me the most bang for my buck.

I'm still curious how a hybrid amp sounds different from an all tube amp. Which will I prefer? (rhetorical question)

Michael

P.S. Guy13: Visiting you sometime is not out of the question. Taiwan is very close to Vietnam as you know. Now how do I get my wife to go along? Shopping? Sunny beaches? Hmmmm?

[Vlad]

Hi Michael,

Where is that audio shop located? I live in Portland, OR and would like to check out Sonus Faber speakers,
but couldn't find any shop that carry them. I noticed you are in OR too.

Thanks,
Vladimir

[mresseguie]

Hi, Vlad.

The shop is called Pearl Audio. The owner, john, is very friendly and helpful. Nice website, too.

Michael

[jupiterboy]

IMO, tubes add back harmonic distortion that is present in certain recordings—old recordings with an acoustic slant, live recordings, etc. This gives our ear/brain information that simulates a live event in a three-dimensional space. SET and high efficiency speakers are going to accentuate this. A push-pull valve amp with coherent speakers is going to give you some of this. SS, well, you can get just a little with a tube pre but you get punchy delivery and some people simply are not happy unless they are getting punched in the face with the music.

This tube effect is not perfect for every style of music. Where you want to be on the continuum is up to your taste and music. I’m kinda middle of the road, wanting a little from both ends of the spectrum.

There’s nothing wrong with a tube integrated that allows you to swap in some different tubes—power and pre—so you can get your feet wet and see what is to your liking. If you find a power tube you really like, maybe that is the path to follow if you ultimately end up in the SET camp. Preamp tubes can completely change the sound/presentation of your system, so the ability to customize is nearly endless.

[atmasphere]

To understand why tubes usually sound better, it is helpful to understand how the human ear/brain system works.

It translates distortion into tonality, also, it uses higher ordered harmonics as indicators of sound pressure.

Knowing these two facts it is suddenly easy to understand why the tubes sound smoother- they make less of the higher-ordered harmonics than transistors do (although if you run a lot of negative feedback on a tube amp, it will also make more higher ordered harmonics as well, thus sounding more like transistors). Its important to understand that these higher orders are in very small amounts, but because our ears use them volume or loudness cues, we are more sensitive to them than almost anything else.

So what we are talking about here is human hearing rules, and the simple fact is that it is a lot easier to build a tube amplifier that obeys those rules than it is to do the same with solid state. This is because many tubes are inherently more linear than transistors, so much so that building zero feedback tube amps really isn't that hard and they can sound fine.

Now tubes usually do make more distortion than transistors, in  case anyone is misunderstanding what is said above. But these harmonics, usually the 2nd, 3rd and 4th, are less noticeable by the human ear, although they do contribute to 'richness' 'lushness' or 'warmth', all terms used to describe this sort of distortion. Herein lies the tubes/transistors debate!

It is possible to design out the even ordered harmonics with tubes, leaving primarily the 3rd harmonic; this is done by making the circuit fully balanced. This is how transistor amps tend to do the same thing BTW, as most transistor amps are fully balanced internally except for the input stage in some cases. If you were to see a completely single-ended transistor amp with no feedback, it too would have a 2nd harmonic as a primary distortion product. IOW, topology plays a role in the types of distortion present.

However there is more to it than that- tubes have a softer (meaning: less odd ordered harmonics) clipping characteristic. This is why they are preferred for guitar amps, and also why you often hear of the concept that 'tube power is greater than transistor power' which is actually a myth; the latter has more to do with how we perceive distortion... in addition, transistors have a non-linear capacitance that is inherent in the junctions of the device- this capacitance contributes to odd ordered harmonic content at any volume level, so its not **just** a matter of topology.

That's it in a nutshell anyway.

[jtwrace]

To understand why tubes usually sound better, it is helpful to understand how the human ear/brain system works.

It translates distortion into tonality, also, it uses higher ordered harmonics as indicators of sound pressure.

That's it in a nutshell anyway.

If that's the case I guess this is why I prefer a neutral amp since I didn't enjoy my M-60's. 

[hdspeakerman]

If I had the money I would buy the MC275 tomorrow.  I have never even heard one but I have been trying to buy a McIntosh tube amp for several years.  I finally gave up and am going to go for a pair of Fisher 30A tube amps.  What is the down side?  If you don't like it I don't think you will have any trouble selling it.  You might be able to work a deal with the dealer for an extended trial in your home.  It is worth asking the question.  You will not be sorry. 

Howard

[geowak]

I like the older Western Electric designs, and also the older ARC ones. But I have not heard many tube designs.

[mresseguie]

Jupiterboy,

"IMO, tubes add back harmonic distortion that is present in certain recordings—old recordings with an acoustic slant, live recordings, etc."

Good point. One of the songs that was played using the MC275 was a female Jazz singer. The recording was made in 1959 (or was it '69?). It was not hi-res, but it sounded fantastic.

Until Monday, I had often wondered what it was that got 'tube-o-philes' so excited. Now I have glimpsed into this other world, and I think I like it.

[mresseguie]

Howard,

I can't argue with your logic wrt the MC275, but I wish to determine if the amps offered by AVA, Roger Modjeski, Atmasphere, and a few others can offer me the same (or nearly the same) performance/sound without the $5500 price tag.

I doubt I actually need 75 Watts to drive my Proac speakers. I've heard what 16 Watts can do at AXPONA, but will it have the sound I want? Time will tell.

Now I get to harass various vendors  about their wares until I finally decide on my next amp.

Can I get the MC275 sound (or close) for under $5500? Here I go......

[FullRangeMan]

In another thread on AC I asked about the 'McIntosh sound", but at that time I hadn't compared amps like yesterday. Now I know.

Now I want to know/understand what other brands of tube amps/preamps sound like. I know about a half-dozen brands (AVA tube amp/FET valve amp, Roger Modjeski's amps, Bottle head, and a few others). Do other tube amps sound similar to the McIntosh amps, or does each brand have its own flavor/sound?

Certainly you now this Sonus speaker are very adverse to a tube amp, as it just 87dB and 4 ohms, this brand are know to be a hard load.

Said it, Mac tube amps from the past(I unknow the current models) have a sound signature by its output power circuit that is over engineered, it have alot of parts and this sound signature is created by the output circuit, not by the sound quality of the output valve.

One can change the output tube to a bad sound version and the sound quality of the amp is the same.

[jsm71]

You mentioned that when you heard the Mac amp at the shop he was running Sonus Faber speakers.  What speakers do you own and how big is your room?  Mating a tube amp to a speaker takes some understanding of the speaker's effeciency, the nature of the impedance load, and crossover topology.   

[mresseguie]

Hi, FullRangeMan.

You are correct about the Olympica I's sensitivity and impedance, but the MC275 had no trouble driving the speakers in that listening room. If I recall correctly, the acoustically treated room is approximately 15' x 23'. My SimAudio i3.3 100w amp drove the Olympica's reasonably well, but I could tell a more powerful amp was called for. I wish I had taken my AVA Synergy amp and my T8 preamp for the comparison as the AVA amp is more powerful than the SimAudio, and the T8 is a tube preamp. Ever since my T8 arrived, I have listened to music with the two AVA units far more than with the i3.3. They definitely sound better.

I have read about the output circuitry you mentioned, but this was the first time I had come face to face (ear to ear?) with it. I am now trying to determine if this is the sound I want to hear all the time, or if I want to become a tube guy without the McIntosh sound.

I chatted with Frank van Alstine yesterday about tube sounds vs. his Fet valve sounds. He was very patient and generous with his time. I say patient because I must have asked every newbie question in the book, and it's likely he's had to answer them a thousand times after so many years. Nonetheless, I'm still undecided on which route I want to take. Of course, the only way to figure out which amp I truly want is to order a couple and listen to the differences--oh so simple, but not without its costs. I'm very tempted to order a 400R to see if this is the sound I want.

Are so many people drawn to the McIntosh sound because they've never heard other tube amps before? Or is it they are smitten by that sound only to discover years later that it's not the sound they prefer? I don't know the answers, I'm afraid.

[sfox7076]

As a person who owned a Ultra 550 Fet Valve and an Ultimate 70, I sold the Fet Valve and kept the Ultimate 70.  The Fet Valve is great.  The Ultimate 70 really just gave me the tube sound I wanted.  I will likely end up selling it in 3-5 months when my 1625 amps are done, but until then, I would not be without it.  To put a finer point on it, the tube sound of the Ultimate 70 is almost holographic.  Where it lacks is bass, but with powered subwoofers, who cares?  The Fet Valves just didn't get me to the nirvana state of high end I wanted.  Don't get me wrong, the amp sounds great, but for that added push, I wanted all tubes. 

The 1625 design I am having built is not a fet valve, but does use some mosfets to regulate oscillation.  That's not a perfect design solution on paper, but the proof of the sound is in the hearing, not on the paper...

Shawn

[mresseguie]

Hello, jsm. (My iPad tried really hard to change that to 'jam'.  )

My speakers are ProAc Response D2 monitors ( 88.5 dB/ 8 ohms). Normally my system is in my home office which is approximately 11' x 15'. It's not actually a rectangle as the entry is a bit angled. I'm not sure how to describe it. For the last three weeks my system has been in my living room/dining room. This room is 13' x 29'. My D2s are about four feet into the room and about six or seven feet apart. My new Rythmik F12G sub is supplying lower frequency support.

I really love how my speakers sound in the living room. They even sound good if I wander into the kitchen or the family room. Unfortunately, my wife doesn't quite appreciate it when the speakers sit "in the middle of the room".  Somehow I suspect others suffer the same complaint from their significant others.

[avahifi]

Just to let you know, the Ultra 550 Fet Valve amplifier is an older model and does not have the regulated output power supplies of the current Fet Valve 400R and 600R amplifiers and is nowhere nearly as refined and engaging as our newest Fet Valve designs.

With the three wildly different speaker designs I use here routinely (Salk HT2TL, Philharmonic 3, and JansZen zA2.1 electrostats) I prefer our Fet Valve amps over our Ultravalve amplifiers.  Although of some interest is that the Ultravalve and Fet Valve 400R provide nearly identical results with the JansZens, the little Ultravalve performing way over its power rating with these speakers, which should not be the case in general with these difficult to drive speakers.

Frank