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Ruben1
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Opinion on Older Mcintosh Tube Preamps Such as MX 110, C20

I am interested in understanding some facts about these older tube preamps....compared to tube preamps made in the 80's and 90's from ARC, CJ, Quicksilver, etc how does the sound of the older tube Macintosh preamps compare, assuming the units are functioning up to spec? Were tube preamps in the 60's designed and engineered significantly different than preamps in the 80's and 90's? Were engineering and design improvements made in the 80's and 90's to the point of noticeable sound improvement?

Thank you.

Ruben

Jan Vigne
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Re: Opinion on Older Mcintosh Tube Preamps Such as MX 110, C20

Your questions are really too broad to answer when you ask to compare the output of the entire industry at any one point in time. If you allow me to stay within the McIntosh line, I can give more pertinent answers.

The McIntosh pre amps were considered among the finest made by any American manufactuer in the days when tubes ruled. One factor that set the McIntosh's apart from most other lines was Mac's attention to detail. Most of the passive components such as resistors and capacitors were spec'd to much tighter tolerances than the all but a tiny portion of the competition cared to use. 1% resistors are not uncommon in a Mac component from the 1950-60's tube era. 10% capacitors exist in most locations in a Mac product from that same time period. For the most part those tolerances would be considered tight quality control for many of today's manufacturers. During this same time frame, many other manufacturers would of course use much higher toleranced parts in their high end gear.

Mac strove for the highest reliability possible in those days - not to say they still don't - and this means their switches and controls were of the sealed variety and thus had fewer problems with oxidation and aging. You'll have to decide what you think about McIntosh circuit quality but most people with the money to spend in the tube years felt they had few alternatives.

McIntosh sound is quite identifiable to those familiar with live music and the general approach American designers took toward their craft. The Mac house sound is big and dynamic with a penchant for staying true to the signal. This won't please everyone today and IMO it won't mate well with some of today's more "hifi-ish" sounding components. Listen before you buy to determine whether you like the McIntosh sound. If you cannot audition the Mac sound from the days of tubes, what Mac produces today (solid state or tubed) is quite the same as the sound they had forty years ago. If you like today's McIntosh, there's a good chance you'll like vintage McIntosh.

When you are discussing Mac tubed pre amps you have to consider the age of the unit and what servicing and repairs it has undergone to it to keep it in top condition. After forty or more years capacitors will have needed replacement in most cases. What parts were used and did the tech stay true to McIntosh's intent when replacing parts? Has someone decided they knew better how to build a circuit than McIntosh did? Is the unit in "stock" condition?

It's unlikely you'll find a forty year old tube pre amp with its original stock tubes, therefore you need to know what tubes have been used as replacements? Did the tech put in the best parts available here or did the tech feel tubes are tubes and as long as it works, that's all that counts. What is the general condition of the unit? The condition of the chrome chassis, glass face plate and lettering on a McIntosh will change its desirability and therefore its price.

After all that you should know that Mac was never a believer in the audiophile jewelery that festoons most of today's market. To be sure some of those passive parts such as connectors do make a difference in sound quality. This would be one of the most significant changes between old Mac and today's products. Old Mac used the best available in the day, which means good quality, individual connectors made from a nickel plated brass collet. (Just so you know, most of today's gold plated connectors have the same brass heart and probably some nickel or other inexpensive but durable material under that fancy gold plating. Many are not individual pieces but a row of gold plated connectors stamped onto a cardboard row and secured only at the two ends. This means you can change the connectors on a vintage Mac with little effort but many of today's gold plated conenctors will pull losse when you try to remove a decent interconnect.) By today the connectors on a vintage tubed McIntosh will have oxidized and will not make their best connection. Any good tech can do a thorough cleaning of the connectors, switches, pots, etc. and look the unit over for potential problems. I would strongly encourage you to take advantage of this service and check up. This isn't only vintage McIntosh that should have this sort of servicing but any vintage component. However I would say one of the biggest "differences" between old Mac and today's products is the way the unit is put together in terms of these passive parts.

IMO old Mac sounds great. I use two MC240 tubed power amps from the early 1960's and a MR71 tuner from the same period. These are a part of my everyday system. Other vintage Mac gear has passed through the system and some pieces have found their place in secondary systems. Most folks who have heard my main system like it.

Be careful of any vintage component that has been in storage for any length of time. Capacitors dry up and they will leak soon after you first hit them with 120VAC. There are some specific things to watch for when buying such items and places like Audio Classics' techs and sales staff, who came mostly from Mac and specialize in vintage McIntosh, can assist you when you begin seriously looking at a purchase. http://www.audioclassics.com/

Ruben1
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Re: Opinion on Older Mcintosh Tube Preamps Such as MX 110, C20

Thanks Jan! This is a very comprehensive review.

Since I was broad with my original question let me be more specific. I currnetly have a SS Mcintosh pre, the CR 10. This unit works wonderfully so no specific complaints with it. I now want to try tubes and what I can afford within the brands I want to stay with are in the used market. For Mac gear it is in the relm of MX 110, etc..for ARC the SP6, SP 8, LS15 are within my price range. For CJ the PV 5, PV 10, PV11. Some of these units I have heard but not with my system so I don't put much stock in what I hear if not hooked up to my other components. My other components are a Primare CD 21 CD player and 2 B&K M200 monoblock amps. I am mainly interested in knowing if the engineering of pre amps evolved in a significant way from the 60's to the 80's and 90's such that even the best Mac gear from the 60's just can not compete with gear from the 80's and 90's due to the shear technological and design advances.

Thanks.

Jan Vigne
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Re: Opinion on Older Mcintosh Tube Preamps Such as MX 110, C20

I somewhat still have to say you're asking a question that cannot easily be answered. To hear the talk about how designers reinvented the wheel every design cycle, yes, you'd think the vintage gear should hardly be able to compete with a cheap transistor radio. What did improve massively over the years was the recognition of each part of the circuit and the manufacturing capacity of those component parts. It made the designers better when they had better parts to work with.

That said I would explain the sound of excellent vintage gear, which the Mac is, as true to the music. There was no such thing as the "high end" at the time of the original Mac tubes. No "palpable space", no "warm" sound, no "soundstage depth" to concern the designers with. There was the sound of live music to compare to in order to get the circuit correct after all the technical issues had been resolved. To that end, the sound of music is very much the same today as it was fifty years ago. Ancillary equipment has had major improvements and with it the Mac sound has kept up nicely because the technicians were aware of the intrinsic qualities of music and they were not satisfied until their circuit achieved a musical nature.

Does my McIntosh gear produce "palpable space" and "holographic soundstage presence"? I would say so and those others who have heard my system would, I think, agree. Is it as good as it gets in high end audio? Well, not quite of course, but I know quite well what it would cost to make a substantial improvement in my system and I can't afford it. Does it provide me with hours of involving music? That it does.

I have one friend who heard my system for the umpteenth time this week. He uses newer Mac 300 watt solid state amplifiers and Gallos speakers. His system plays louder than mine and has a degree better resolution of low level detail. However, my overall system sound is still what he aims to achieve.

I'm familiar with the BK monoblocks and have heard them in my system compared side by side to my amplifiers. The BK's have a shade better resolution of trailing edges than do my amplifiers. The BK's are, in the end, somewhat quieter than my four decades old amplifiers and this I would think accounts for their slightly improved decays when compared to my amps. As notes faded into the background the BK's were just ever so slightly better at defining the ambient space of the performance hall than my amps can manage. My amps had a better midrange timbre and texture and a more easy going nature that drew me further into the music than did the M200's. The BK's still exhibited the "MOSFET mist" compared to the open airiness of tubes. Which of the two you might choose would be a matter of budget and system taste. By way of comparison, I heard much the same improvements when I introuced a Jeff Rowland Design Group amplifier to the mix. The Rowland had the involvement of my amplifiers along with the low level resolution of the BK's and then some along with a bottom octave that neither the tubes not the MOSFET BK's could manage. But, overall, the three amps were more similar than not.

Now, do keep in mind my amplfiers were updated not long before I made this comparison and the tubes in the Mac's were quite good. New passive parts made a substantial improvement in the basic sound of the vintage McIntosh even though no circuit changes were introduced. What I have is not exactly what you will hear from a dead stock vintage McIntosh product, close but not quite.

IMO the McIntosh Unity Coupled transformer design is still excellent and almost anyone involved in tubes will tell you it is the sound of the transformers you hear most when comparing vintage amplifiers. Of course a pre amp wouldn't be concerned with outut transformers but this is the sort of technology McIntosh brought to the market in their tubed equipment from the 1950-60's. I've heard a C22 compared to newer pre amps on numerous occasions and I would very likely take the Mac design over most of what I have heard. As you can guess I'm a McIntosh fan so take that into consideration when I make these comparisons.

My opinion is you can't really go wrong with vintage McIntosh, they seldom made a product that has not increased in value. That alone should provide a means to listen to any vintage Mac gear and, if you decide you aren't a Mac fan, move on by selling the unit for what you paid for it. Free hifi! What a deal!

JSBach
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Re: Opinion on Older Mcintosh Tube Preamps Such as MX 110, C20


Quote:
The Mac house sound is big and dynamic with a penchant for staying true to the signal. This won't please everyone today and IMO it won't mate well with some of today's more "hifi-ish" sounding components.


Great post Jan, especially the warnings about aged electronics.
You say about Mac sound "McIntosh sound is quite identifiable to those familiar with live music and the general approach American designers took toward their craft. The Mac house sound is big and dynamic with a penchant for staying true to the signal." and I agree. I find myself wondering though, is that approach undertaken by any other manufacturer today and if so are they pricing their gear at a similar level to Mac? Sadly I suspect that when we learn how to do something properly it's never going to be at bargain prices.
From my perspective Mac have only made one big boo boo, the styling of their new turntable. Others may love it but it makes me laugh out loud whenever I encounter it.

Jan Vigne
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Re: Opinion on Older Mcintosh Tube Preamps Such as MX 110, C20

There are other brands with a "big" sound similar to the Mac house sound. Rowland is one of them IMO, Conrad Johnson another. That isn't to say they sound identical but I would think all three designers have more things they hear in music that are alike than not. Unfortunately, both lines sell for as much or more than McIntosh though, I think, a few of the C-J products can be had pre-owned at reasonable prices for what they represented at the time of their introduction. One of my personal favorite pre amps is the old CJ5. Not at all accurate but the mids were glorious and what it did right sure was fun.

In budget gear, I still haven't found any budget gear that can live up to the McIntosh/Rowland sense of "bignesss". You have to pay for that.

tom collins
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Re: Opinion on Older Mcintosh Tube Preamps Such as MX 110, C20

jan: thanks for the tutorial on mac. you said you are a fan, i would say that is an understatement and i mean that as a compliment.
when i was young, mac was the unobtainium, at least for our family. i was always curious about it.
now we have a dealer that carrys mac in my area. mac also makes speakers, but i have found that i like the mac hardware better with other speaker brands. i heard a 275, which i think is a newer version of your 240. it was using a mac solid state preamp and cd player driving focal 1037 electras. it was unbelievable. those "little" stand mounted speakers just threw it all out into the room and the bottom was so precise and controlled it seemed the opposite of what i had heard about tube amps. they also have a huge set of 1.2kw monos and all the top end gear hooked to a large set of mac speakers. that set seemed nowhere near as engaging. strange. i wanted to love it giving how much it must of cost, but wound up loving the comparatively inexpensive setup. you never know.
i currently use solid state british gear and have to say the sound seems different between the two.
thanks again.

Jan Vigne
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Re: Opinion on Older Mcintosh Tube Preamps Such as MX 110, C20

At the time of the MC275 the Mac power amp line up was, from lowest to highest wattage,; MC225, MC240 & MC275. The tube compliment went from EL34's, 6L6GC's to 6550's. All used the same transformer design with the difference being the power rating for each. The circuitry of the MC225/MC240 is identical and the only significant diference between those two and the larger MC275 was the addition of another driver tube on the input side. The "MC" was the McIntosh label for a power amplifier and the last two digits defined the rated power output. The "2" preceding the wattage number identified the amplifier as a two channel, "stereo" amplifier. In keeping with the tradition of the time, Mac also offered mono versions of each amplifier which enabled past Mac customers with a mono amplifier left from a previous system to upgrade to true stereo operation with the addition of the second single channel ampliifer. This was also how Mac and most other companies at the time dealt with the other components being switched from exclusively mono to two channel systems. http://www.roger-russell.com/aboutmc.htm The sound of all the Mac amplifiers was as close to each other as the different tube types would allow.

When McIntosh introduced their first solid state amplifiers the two lower priced tubed amplifiers were soon dropped from production and only the MC275 remained. It stayed in limited production until 1971 by which time tubes were all but a forgotten item waiting for an enterprising designer to revive a few years later with a new company and the beginnings of the "high end" industry.

The MC275 has had several revivals in various guise and with minimal circuit changes to reflect the different ancillary equipment found in today's consumer market. The first revival being the "Gordon Gow" limited edition version produced soon after Mac went to Japanese ownership. With the introduction of a balanced input stage today the MC275 is a good seller with Mac selling each and every unit it produces before any hardware hits the assembly line. The current MC275 still resides in Stereophile's Clas A ratings for tubed power amplifiers. This is 47 years after its original design/production.

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