February 2017


McIntosh C2600 Vacuum Tube Stereo Preamplifier
With DAC, Phono Stage And Headphone Amplifier
A newfound family heirloom. For a lifetime... and longer.
Review By Tom Lyle

  The McIntosh name can bring up all sorts of memories, images, assumptions, and yes, yearning for many audiophiles and non-audiophiles alike. The first thing that comes to my mind when I think about McIntosh components is their history. One of the first pieces of high-end equipment I ever owned was a McIntosh MC-30 monoblock, a pair of which powered speakers in my basement system in the 1970s while I was still in high school. McIntosh has changed owners a few times, yet their products are still made in the USA – in Binghamton, New York. They were founded in 1949, moved into their Binghamton factory in 1956. McIntosh is the leading company in the McIntosh Group of audio companies, with all engineering, design, and production taking place in the Binghamton location. I could fill quite a few pages discussing McIntosh's history. I won't.

Instead, I'll say that McIntosh continues to produce products that are instantly recognizable by all but the most sheltered of audiophiles. When the McIntosh C2600 preamplifier arrived at my home for review, I immediately installed it in my system. The C2600 looked fabulous on the third shelf of my Arcici Suspense equipment rack. On its front panel were its two recognizable blue meters on either side, the McIntosh name in its familiar font glowing a soft green smack dab in the center, and its two silver rimmed control knobs on either side made me feel as though I had arrived. Finally, after more than 35 years, I once again had a McIntosh component in my system.

These days, my reference preamplifier is a Balanced Audio Technology (BAT) VK-33. Like the McIntosh C2600, it is a vacuum tube unit. But lately I've been using many other preamps in my system. All of them have been excellent solid-state preamps. These days, the difference in sound one gets when using a solid-state preamplifier vs. a vacuum tube preamplifier isn't a huge one. Certainly not as huge as it once was. Both solid-state and vacuum tube component manufacturers are getting very good at making preamplifiers that sound like excellent preamplifiers, and the difference between these excellent preamps often has more to do with the fact that one is powered by tubes, the other transistors. And sometimes it does have to do with the fact that one is powered by tubes, the other transistors! Yes, there are differences, and these nuances are what separate similarly priced preamps from each other.

Staring Up
After the McIntosh C2600 was in my system for a while and I assume fully broken-in, I then started my serious listening sessions which consisted of listening to my favorite selections on LP and from my music server. It didn't take long before I determined that the C2600 had a sound that was undeniably powered by tubes. From the looks of the preamplifier, it is also obvious that McIntosh is proud that the C2600 is powered by tubes, as there is a large glass window that allows one to view six of the small preamp tubes in the preamp's interior, four allocated for its phono preamplifier, and two for its linestage, along with the C2600 specifications, and a chart diagram of the workings of the inputs and outputs of the preamplifier.

A superb feature of the McIntosh C2600 is that it contains both an internal digital-to-analog converter, and a phono stage that accepts both Moving Magnet (MM) and Moving Coil (MC) phono cartridges. I started my review without using the C2600's internal DAC or its built-in phono stage. Instead I used my current reference for an affordable outboard DAC, a AURALiC Vega. My phono preamp is the excellent Pass Labs XP-15. Using my own DAC and phono preamp allowed me to acquaint myself with the characteristics of the McIntosh preamp before I auditioned its onboard DAC and phono preamplifier.

The digital source was largely provided by my PC based music server, feeding the DAC via a rather long Furutech USB cable. The analog source remains my Basis Audio Debut V, with either a Gold Note Tuscany or Van den Hul Crimson Stradivarius cartridge (review forthcoming) mounted on a Tri-Planar 6 tonearm. Yes, it's obvious that my analog front-end outclasses the digital front-end by a bit. This doesn't mean that I didn't listen to digital sources, the AURALiC is a fine DAC, especially when one considers its price, and especially when one plays DSD files through it. It is just that I spent more time listening to records.

The C2600 preamplifier, according to McIntosh's literature, is a direct descendant from their C2300, which they say was one of "the most admired" McIntosh preamps they've ever produced. The successor to that preamp was the C2500, which was even more popular. The C2600, reviewed here, incorporates "the best of previous models", according to McIntosh. While they've added an internal digital-to-analog converter, they also upgraded the tube circuitry of the preamp. Not only does the C2600 have an internal DAC and phono stage, but also sports a headphone output. Its rear panel has three balanced inputs, four unbalanced RCA inputs, and three balanced (XLR) and unbalanced (RCA) outputs. Its digital inputs are many, including three optical, two coax, one USB and McIntosh's proprietary MCT connection for when using McIntosh digital sources. The optical and coax digital inputs of the C2600 can decode digital signals up to 24-bit/192kHz, the USB input accepts PCM signals up to 32-bit/384kHz and supports DSD64, DSD128 and DSD256 plus DXD 352.8kHz and DXD 384kHz.

One can use the C2600 to bi-amp, or even tri-amp a set of speakers, since its three stereo outputs can be connected at one time; two of them can be switched on and off. This also makes it much more convenient to use the C2600 as part of a multi-room system. All this, and the excellent fit and finish and its appearance -- that cannot be mistaken for any other than a McIntosh component.

The C2600's inputs are programmable. Even though it seems that most modern preamps from the larger high-end audio companies offer this feature, there is no denying that this feature is very convenient. Also, programmable are the bass and treble controls, which can be adjusted for individual sources as needed. And naturally, there is the ubiquitous theater bypass control that makes this component a good fit for systems that double as a home theater's audio system. All these features are very nice, but it was even nicer to discover that the C2600 has a front panel headphone output.

This headphone output has a "Crossfeed Director" which McIntosh calls HXD, which many headphone listeners are familiar with, that adds a bit of one channel's signal to the other to lessen the "inside the head" feeling that may occur, especially when listening to some less expensive headphones. There has been some debate as to whether the slight loss in transparency when using this control is worth it. When listening to more ambitious headphones, my answer is certainly no, but I can understand one at least trying it for themselves to make this decision for oneself.

When I opened the cabinet of the C2600 I was impressed how neatly everything was assembled. No solder drips in here, thank you very much! I'm the sort of person that when viewing such an orderly layout I consider it a work of art. Still, there is no doubt that the guts of the C2600 is quite impressive. McIntosh says that the analog and digital sections of the C2600 are physically separated using a dual chassis design to "prevent signal corruption". The analog and digital sections are housed separately in the dual chassis design to prevent signal corruption. All in all, a very nice looking preamplifier, inside and out. Programmable inputs, internal DAC, phono stage, defeatable and programmable bass and treble controls, and a headphone output? Very nice.

Setup And Listening
I was lucky to have a relatively large amount of power amplifiers and several different speaker systems in my listening room at the time of this review, and it was nice to be able to see how well the McIntosh C2600 matched with these amps and speakers. For the most part it really didn't matter that much which power amp it was paired with (with one exception), and matching it up mostly depended on which speakers I was using with the power amp, which makes sense. Some of the amplifiers are powered by tubes, some solid-state, so I think this enabled me to isolate the character of the C2600 very well. The best match in my system, and the amplifier that I used for the bulk of the review when paired with the large Sound Lab electrostatic speakers was the solid-state Pass Laboratories X350.5.

The biggest mismatch was when I paired the C2600 with the Aries-Cerat Diana Forte, a parallel single ended triode (SET) 60 Wpc tube amp built around 813DHT big bottle tubes (review forthcoming). The treble and deep bass suffered greatly. Still, as I said earlier in the review, it was apparent that its sound of this McIntosh was undeniably powered by tubes, yet with the majority of the amplifiers I paired it with, this was a good thing, especially when speaking of midrange character. This is where most of the music lives, and depending on one's speakers, might make this preamplifier a perfect fit. One album that I played while the McIntosh C2600 was in my system that I played more than once was the eighth studio album by P.J. Harvey, Uh Huh Her. It is a pleasure to be able to speak of an artist that I've been listening to since her first album Dry was released in 1992, and to be able to listen to an artist that I have the same respect for since I did in the beginning of her career. For some reason, some hip music critics have taken umbrage to the fact that she keeps changing styles. One would think she's be labeled a chameleon or something of that sort, but who am I to second guess professional music critics? I don't. So, I end up feeling as if each album is an exploration as to how she is going to approach her music, moth lyrically and stylistically. On Uh Huh Her, she delivers a set of tunes that are somewhere in between the aggressive approach she used when she first started out, and the more bucolic albums she has recently released.

The sound of P.J. Harvey's vocals, regardless of which format I played, sounded spot on. There is no way of telling how they recorded these vocals, but when playing this record through the C2600 it was as if I was a fly on the wall of the studio. There was more of a sense of listening to the playback in the control room rather than standing next to her as she sang. Still, with the McIntosh in the system her vocals sounded extremely realistic. Often there is a bit of distortion added to her voice, which of course gives her vocals a more aggressive feel, but when listening to them in the context of the songs I still felt as though I was one of the privileged few that was attending the recording session, sitting on a couch in the control room, drink in hand listening to the playback, nodding my approval. The C2600 also displayed a dynamic distance between her voice and the instruments that are backing her up. It was as if the vocals were allocated a space in the soundstage that were reserved for her vocals, but at the same time were musically inseparable from the rest of the music on the track.

Even though I mentioned that occasionally some effects were added to the sound of her voice, there were very few overdubs on her lead vocals. Her voice wasn't doubled, and that led to a greater sense of separation in this soundstage. There is a certain magic with tubes, and this sense of dynamic distance is one of the characteristics I love – where two sounds, whether they be instruments or voices that end up in the same area of the soundstage, often playing at the same volume, are kept separated to give a much more realistic sound – even if this recording is one that has been assembled on a multi-track recorder, such as this great album by P.J. Harvey.

Whether the bass and treble response of the McIntosh C2600 will be sufficient in one's system will depend greatly one's associated gear, and especially one's speakers. When I used the C2600 in my second system located in a common space in our home, its performance in the lowest bass and even its highest treble sounded much better. My reference speakers in this system are the EgglestonWorks Isabel Signature, which have a bass response that is specified to go as low as 40Hz. This is certainly a respectable level, as the lowest string on a bass guitar's frequency is around 41Hz. Yes, the fundamentals frequencies on a recording go much lower. But the sympathetic frequencies and resonance response of both the speakers and one's room will come into play somewhat. But that's not what I'm talking about here, I'm talking about if the McIntosh was sufficient in this system given that the C2600 lowest bass and highest treble weren't its strongest traits.

The room that this system is in a much livelier sounding room, and that undoubtedly helped me enjoy the high frequencies. In fact, the burnished sound of the highs coming forth from the C2600 on the strings and metallic percussion on the Bruckner's Symphony No. 5 conducted by Nikolaus Harnocourt on a RCA Red Seal SACD sounded gorgeous. This large orchestral piece sounded huge through the McIntosh C2600, filling the front side of the room with a massive, yet realistically scaled soundstage. The strings sounded very powerful when they needed to be, as the Vienna Philharmonic on this recording sounded as if it was staffed with awfully talented musicians, which it obviously was.

The strings could also sound quite delicate through the C2600. This symphony is sometimes called the Pizzicato, as three of the four movements begin with pizzicato strings. In the beginning of the second movement, Adagio, this string sound is especially poignant. It wasn't as if I could pinpoint their exact location in the soundstage, but the sound was if it resounded throughout the proscenium of the Musikverein, and thus filled the right side of the soundstage with this palpable sound. Played through the C2600 It's easy to tell why some swoon over the sound of the Vienna strings!

Eventually, I connected my turntable to the McIntosh C2600's phono stage, and my music server to its internal DAC. I was awfully impressed with both, but especially the C2600's phono stage. The C2600 has two tubed phono stages. The McIntosh C2600 used six, 9-pin dual triode tubes where each tube has two identical amplification sections. Out of the six tubes, two are for preamp function, two are for Moving Coil and two are for Moving Magnet. One could connect two turntables, or one turntable with two tonearms, to the C2600 – one Moving Coil (MC) cartridge and one Moving Magnet (MM) cartridge. I was only able to test the moving coil input of the C2600's MC phono input, as I had two MC cartridges on hand for this review, one of which had a rather low output of only a bit over .2mV, the other a more robust 0.7mv The C2600's phono stage was able to not only bring this cartridge with the very low output to a usable volume, but a volume that was just about equal to the digital input without having to adjust the programmable input volumes, only by raising the MC input's volume with the appropriate settings.

The sound of the McIntosh C2600's phono stage had just about the same characteristics of the linestage section of the preamp, yet multiplied by two! It is an incredible sounding on-board phono stage. In direct comparison to my reference Pass Labs phono preamplifier it fell it little short in absolute terms, but judged on its own, it was quite a performer. At one point the Pass Labs unit had to be sent to California for repairs, so I connected my turntable to the C2600's MC phono input. I then took the fixed output of the C2600 (in lieu of a record-out, which I didn't notice on the rear panel) and connected it the rest of my system. The phono preamplifier of the McIntosh can be compared to outboard phono preamps costing in the range of $2000. It is an amazing performer. Lush, yet has enough transient detail to satisfy.

A Lifetime Of Musical Pleasures
I could only imagine the performance of McIntosh's MP1100 phono preamplifier! The internal phono stage of the C2600 matches its linestage perfectly – it has a beautiful sounding midrange that brings out the best in vocals and string sounds, and although the very lowest bass and highest treble frequencies seemed a bit attenuated, with good system matching this might not come into play that much. The internal DAC of the C2600 is that it is as transparent as one could ask for. The resulting sound of digital sources played through the internal DAC sounded as if it were a direct connection to the C2600's linestage. It didn't add any of its own sound. Sure, if I compared it directly with the resident AURALiC Vega there were some errors of subtraction, mostly in the area of dynamics and instrument separation, but still, for an internal DAC in a preamplifier at the price level of the C2600 it is quite impressive, especially its functionality, as it has seven, count ‘em, seven digital inputs! I don't think there is any audiophile that is going to feel short changed using this digital section.

I am very, very impressed by the McIntosh C2600. Lately, I've reviewed a few preamplifiers that are priced much higher than this preamp, but when I put the McIntosh C2600 in my system I was pleasantly surprised. I was not only surprised with its sonic performance, but that this performance comes with so many features. Its number of inputs, tone controls, programmability, not to mention high-performance internal DAC and superb phono section, all for $7000. I recommend the McIntosh C2600 for all audiophiles who love tube sound, and are looking for a true preamplifier – not just a simple linestage – at a relatively affordable price. Add to this the reputation of McIntosh, which will allow one to upgrade in the future, and as a bonus own a preamplifier that retains much of its purchase price. But I have a feeling that this preamplifier will be thought of as more than just an heirloom. Instead, I think any owner of a McIntosh C2600 will be too busy enjoying music through this preamplifier. For a lifetime and longer.

Specifications
Type: Vacuum tube stereo Integrated amplifier with DAC
Frequency Response: 15Hz to 100kHz (+0/-3dB) 
Tube Complement: Six tubes, five  12AX7A and one 12AT7
Total Harmonic Distortion: 0.08% from 20Hz to 20,000Hz 
Rated Output: 2.5V Unbalanced, 5V Balanced (Main) 450mV (Fixed Output) 
Maximum Voltage Output: 8V RMS Unbalanced, 16V RMS Balanced
Sensitivity: High Level, 450mV Unbalanced, 900mV Balanced
Phono MM is 4.5mV and Phono MC is 0.45mV 
Signal To Noise Ratio: -100dB normal,  MM/MC Phono is -75dB 
Input Impedance: 22kOhms unbalanced, 44 kOhms balanced
Phono MM - 50 to 800pF, in 50pF steps; 47K Ohms
Phono MC - 25, 50, 100, 200, 400 or 1,000 Ohms; 100pF 
Voltage Gain: 15dB Phono MM to Record Output: 40dB Phono MC to Record Output: 60dB 
Output Impedance: 100 Ohms unbalanced, 200 Ohms balanced 
Headphone Load Impedance: 100 to 600 Ohms 
Digital Input:
   Optical: PCM - 16Bit, 24Bit - 32kHz to 192kHz
   Coaxial: PCM -16Bit, 24Bit - 32kHz to 192kHz MCT: PCM, SACD, -16Bit, 24Bit - 32kHz to 192kHz
   USB: PCM - 16Bit, 24Bit, 32Bit - 32kHz to 384kHz DXD - DXD352.8kHz, DXD384kHz DSD - DSD64, DSD128, DSD256 Power control and trigger output: 12VDC, 25mA 
Dimensions: 17.5" x 7.675" x 18" (WxHxD)
Weight: 29.5 pounds 
Price: $7000

Company Information
McIntosh Laboratory, Inc. 
2 Chambers Street 
Binghamton, NY 13903

Voice: (607) 723-3512
Fax: (607) 724-0549 
Website: www.McIntoshLabs.com