Macintosh vs Pass labs

Know_talent, thank you for taking the time to explain.
I still don't think McIntosh are as universal of amplifiers as some other amps, but that's just me.
I won'd be calling McIntosh as I have no interest in their amplifiers. At least not right now. Your explanation is enough.

Audphile1...

The whole purpose of the autoformer is to create an ideal impedance match with the speaker being driven.

If you have a speaker that runs 8 ohms nominal impedance and run it off the 8 ohm terminals you'll get the 500W into 8 ohms, 1000W into 4 ohms and, for short excursions, 2000W into 2 ohms. Depending how much the impedance curve dips below 8 ohms will dictate how much extra current the amp is producing and the power sentry will shut it down when it senses too much heat.

Same thing again, but this time you instead hook up to the 4 ohm terminals. Now you're getting 500W into a 4 ohm load, 1000W into a 2 ohm load and 2000W into a 1 ohm load...though probably only for brief transients or the power sentry will shut things down do to thermal overload.
Notice how the amp doubles power as impedance is halved..
Conversely a 8 ohm load, when hooked to the 4 ohm terminals will be 250W, half the 500W rating.

Theoretically if you hooked up to the 2 ohm terminal you would generate 500W into a 2 ohm load, 1000W into a 1 ohm load and 2000W into a 0.5 ohm load...but I'm pretty sure the amp is not designed to handle such a difficult load???
A 4 ohm load would be 250W, while an 8 ohm load would be getting 125W.

The intent of the autoformer is to best match the nominal load of the speaker so the amp is not overheating with large impedance dips.

Think of a conventional amp with single output taps that is rated for 500W into 8 ohms, 1000W into 4 ohms and 2000 into 2 ohms. If you hook up a speaker to this amp that has nominal impedance of 4 ohms, with occasional dips into 2 ohm range you will obviously have an amp that is running quite hot!!! Now hook that same speaker up to the 4 ohm terminals of the autoformer and you'll have just 500W available at 4 ohms and 1000W into 2 ohms, but the amplifier will run much cooler and therefore last longer.
You could hook the speaker up to the 8 ohm terminals and get the 500W into 8 ohms, 1000W into 4.... but the heat would be so great that the power sentry would shut the amp down depending on how much time was spent in the lower impedance regions.

Call Chuck Hinton from McIntosh he might be able to explain it in simpler terms.

Know_talent, I read your post few times and I can't seem to understand it.

Though McIntosh autoformers deliver rated wattage at 2, 4 and 8 ohm terminals, they still double power as they go down. That is why people experience thermal overload when hooking up B&W's to the 8 ohm taps. The current draw heats up the unit and it shuts down.

Rated wattage for, let's say MC402, is 400w/ch. If this is what the amp delivers into 2, 4 and 8 ohms, how does it double down?

I've heard a 100w/ch McIntosh stereo amp in the store driving B&W N803 for about 40 seconds on a normal volume. Well, I wasn't the one who experience thermal overload. That McIntosh amp was. It just shut down. At the time I had at home a McCormack DNA-0.5 Deluxe, that was rated similarly to that McIntosh amp. I never had a problem driving the N803s with it. Granted, the speakers were underpowered by this amplifier, but it never stopped playing. That McIntosh amp simply gave up in a relatively short time. I call that unacceptable.

Now, your last paragraph, again is unclear, when you mention that a MC501 only delivers 250w/ch from its 4ohm posts into an 8ohm load....how's that? A speaker(i.e B&W 800 series) can have an impedance curve and go from 8ohms to 3ohms, depending on what's playing and how. So what good would the MC501 be?

I understand things like brand loyalty and I'm not bashing McIntosh amps. I think they're fine amps and there are certainly people with the right speakers with which these amps sound great, but, I guess I just don't understand all this autoformer principal and how it works(if it even does).

If we're making Euro auto analogies I'd argue that McIntosh is more like an Audi A8L than a Buick...

Though McIntosh autoformers deliver rated wattage at 2, 4 and 8 ohm terminals, they still double power as they go down. That is why people experience thermal overload when hooking up B&W's to the 8 ohm taps. The current draw heats up the unit and it shuts down.

The 501 monoblocks were tested by Stereophile and found to deliver 720 watts into a 8 ohm load (and similar from their respective 4 and 2 ohm taps) so the overall 500 wpc rating is quite conservative.
Hook B&W's up to the 4 ohm terminals and the 501 is capable of delivering over 1000 watts into 2 ohm load.
Conversely, when running off the 4 ohm terminals the 501 is only delivering approx 250 watts into an 8 ohm load.

It seems that Macs are are very synergistic with karaoke systems because I've seen a few of those.

I see Pass amps come up for sale X250,X250.5 and are gone in one day. Not just on one ocaasion. Also after more research I think Audfile's analogy is on the money. I also think that for the VRSR the pass is a perfect match. I am going to confirm that with Albert. Any one who has not listened to these speakers should. Just upgraded mine to the mark II and they sound even better then I could have imagined.

I've never heard Pass but have heard mcintosh and do like it. Interesting though I know someone who was a very large Pass dealer and brought in Conrad Johnson and at that point the pass sales declined to the point he dropped the pass line. He said with the two on the floor at the same time the cj sound won out in most cases. I own cj stuff and its hard to want anything else although I'm upgrading now and no cj dealer here but my main dealer I buy from sells mcintosh and I will give them a strong look out of loyalty to the dealer.

No one has mentioned it; but what preamp do you have?

You really need to try Pass X1 preamp or something at that level before changing your amp out.. I find the preamp can provide one of the largest flavoring or clarity controls.. If you haven't heard a premium preamp you have no idea what you are missing. Also make sure to run Balanced as my friends X1 really sounds better with XLR inputs and outputs because of the fully balanced design.

Since you have VR speakers you probably like to listen with a little volume, try to go to the 501's instead of the 402 if you are a bass head.. The MAC 402 uses a parallel design versus the higher end design in the 501 and the 1201 amplifiers and keep in mind autoformers don't double in power as impedence drops so your X250 has more 4ohm current than the MC402, and the MC501 are a different design.

One of my friends owns the MC402 and loves the look and flavoring and even more so with the latest Mac Preamp.. His system has very good synergy and the Mac gear tailors to his musical preferences..

Between those two choices I would lean towards Pass X250.5 or an X350.5 since more power never hurt anyone. I have a friend with VR 4 GEN III SE and he uses a pair of Parasound JC-1 which have insane control over his bass modules, and the adjustable Class A bias (10 or 25watts with a switch) he enjoys. The Parasounds need 1200+ hrs to break in but are a bargain in my opinion.

Oh yeah don't worry about how many are for sale, audiophiles are just obsessive... there has to be something better right ;-) how many of us have upgraded and ended up moving backwards... The good thing about Mac gear is the dealers don't discount much so the prices on the used market stay high so you can always turn it.

IMO the higher-end Mac's sound better than the high-end Pass amps. I've listened to both and although I had high expectations for the Pass stuff, I just wasn't impressed. Listened to a nice setup on some huge Genesis speakers. It did sound different but not that great. Also the volume was scratchy when adjusted which gave the appears of lower quality. The high end Mac system I heard on Focals was one of the best systems I'd ever heard - in my top 3 of all time in fact. Now the low-end Macs (integrateds) are a different story.

McIntosh is like a Buick Park Avenue. Where Pass amps are more like a BMW M5. Performance, design and implementation of the Pass Labs amplifiers is heads above the Mc.

And what's up with the cheap turn buttons on the Mac? Do they just visit some junk yards looking for some 1950s, 1960 cars, rip the buttons off their radios and mount these on their amps and preamps? C'mon!
Take a look at the latest McIntosh creaton - their turntable. It's as beautiful looking as Pontiac Aztec. Who aproved that design? Stevie Wonder?

I had a 402 and sold it when I tried the 250.5. The Pass had WAY more authority, muscle, and clarity from top to bottom. The Mac sounded "soft". My speakers at the time were VR-4Jr.

The 350.5 is a big improvement over the 250.5 , O-Well it's only money.

I had that same urge as you for years and I am glad I have finally been able to own the Mac gear.

As others have already said, your comments that you are very pleased with your Pass amp speaks plenty. As someone that has messed up systems I have enjoyed, my advise is to keep on enjoying your system, or as others have said, go to the 250.5 if you must. Nelson Pass is highly regarded for the amps he makes and has made through the years.

Thank you all for your responses. While I think they both have thier good and not so good points I get the feeling the Pass is hard to beat. I will second that.Happy listening

I own the 501's and when I was auditioning against the 402 I thought there was a big difference, not so much sonics but power and total lack of compression when pushed. This was important to me because I drive Thiel 3.6's.

Auditioning an amplifer at a dealer with unfamilar components is basically useless.

Characterizations such as "strident" or "dry" or "lean" or whatever adjective one chooses, is a function of the system, room, and listener's preferences not a single component.

listened to the Pass XA100.5 monoblocks recently at a dealer- the highs seemed a bit 'strident' to me (Hovland HP-200 preamp; Gershman Avantegard speakers). Feel that my Symphonic Line RG4 MKIII monos do not have this issue, and be much more even across the frequency spectrum... MAC would interest me more than Pass.

Just reading along: I get confused as to which Mac blocks are their best. I read many here think the 501's Then in TAS I see they use the 436'es to review 25k speakers. Which is better? I probably would have gotten the Pass 350.5 but it it just to heavy; untill I get that car-motor engine lifter installed in my ceiling.

If you want a McIntosh amp, by all means get one and try it. That way you can make your own decision. You can always resell at no loss if you make a wise purchase.

Personally, I feel the latest McIntosh amps have superlative microdynamic detail and information, which make instrumental timbre exceptionally accurate. They also have a natural coherence that puts the soundstage together perfectly IMO. Give it a try and see what you think.

Arthur

I had called Pass Labs about 7-8 years ago and talked with Nelson. This, as I remember, was during CES and he had stayed behind that year and was answering the phones. I have been a tube guy since the mid 80s and explained this to Nelson saying I was considering going SS to see how the designs had progressed.

Nelson said he was also a tube fan and knew where I was coming from. However, he his amps would not satisfy my tube based musical tastes. Said I should stick with tubes based on what I like in music reproduction.

I thought this was brutally honest and proof that Pass is a company building the best electronics they can without overriding desire for profits first. This is the kind of company that deserves our support. If I ever decide to go SS I will check Pass products (although I have a Plinius SA50 MKIII that is very musical).

Between Pass and McIntosh, it´s like apples and oranges - both taste very well. For example, the German magazine Stereoplay likes the Pass X 350.5 very much, and in its Nvember 2005 issue compared it to McIntosh´s 501s. The Pass sounded more "more massive and elementary", but 501s won, offering more fine details and considerably better imaging and space definition.
Regards,
Florian Hassel

Yes you cannot imagine how well McIntosh sells in comparison to other brands of equal quality or I venture to say better sonics. The reason they are found for sale more frequently than others, as allready said is a function of the numbers sold.
I can tell you that there are probably more Mc s around and working thanalmost any other amp brand. The most freuently offered amps date back to the first generation of SS amps 1967. Those are the Black glass Blue meter designs still used today by MC. The others are often the early tube amps which are collectable and widely admired. However they have been reintroduced in a number of reissues as in the MC275, which continue to draw the audiophile and the Smash Bang Harley Davidson Amps we all at one time aspired to own. They are very reliable, well built and last longer than an army of everyready bunnys. I own a 1973 2505 was a direct descendant of that first SS and still most popular of the initial designs the 2105.
I didn't want to pay a fortune and the 2105 was commanding more than it does now as it delivered over 100wpc and was the best known. The 2505 was a less powerful alternative. To call it low power is misleading, like all good Amps the wattage rating is not very meaningful, it's the power delivered when needed and before it clips. The 2505 is the so called littlest of the black glass blue meter amps that began the SS amps. It's trannies that are much larger than almost any amp so rated.
Some had autoformers and technical improvements like powerguards, with big price tags to match.
The all important "prestigious" nature of being a Mc owner was firmly established by the time Mr. Pass was just begining to think of becoming an amp designer.
It is still considered the best and the quintesenntial American made amp around, if a typical consumer, old enough to know the word Stereo.
They would roll over if they knew they were owned by a Japanese conglomerate which bought the first Japanese multinational that bought MCc a long time ago.
I can't substantiate this but have heard that fairly large sub components aren't built in the U S of A or Japan but a rather large country in Asia.
The sonics of MCs, IMHO are not as nearly as detailed layered as tonally balanced as most Pass amps, so if you do buy a Mc like I did. Have an application beyond the Von Schweickerts in mind. They work well as the motivators for my Klipsch speakers, LaScalas and Heresys. Many acknowledge these as a very odd but very good synergistic pairing.
I any event my advice, which is worth what you paid for it, is hold onto the Pass if you like it/them. If you want to play with the MCs, anyway, try em before commiting a ton of money to buy em or ...
You might like to take your system in a totally new direction and consider a tube amp. The VSAs I have hold their impedance level and up, thus work well with moderate sized tube amps.

both are great, but mac sells many, many more amps than most.

Could the reason for higher Mac resale be due to higher sales volume compared to Pass?

I recently purchased a Mac Mc402 for my system - I cant believe how great my system sounds, I find myself listening to all my music collection and enjoying listening again.

If you are serious you should take the effort to arrange to bring a demo Mc402 or pair Mc501 mono blocks into your system and answer your grass may be greener question.

Happy listening!

Greg.