McIntosh C28 Preamplifiers

C28

Full function preamp

User Reviews (6)

Showing 1-6 of 6  
Dwight   Audio Enthusiast [Feb 23, 2003]
Strength:

Very pretty and quite. The trim control is also helpful in boosting the frequencys under 50 hz. I run it at half, about 3dB. It's worth more than I paid for it after 32 years of use!

Weakness:

No remote control. Limited inputs for AV. too many tape functions, I don't use any. I had a bridge rectifier fail 20 years ago and DOB replaced a transistor when it was a few years old.

I've owned and used the C-28 since new in 1971 and have never found any fault with it. When I upgraded from Phono to CD several years ago I noticed a big improvement in sound quality. Recently I went to a Crown PT2.1, 325wpc power amp from a Mc 2100. I believe the higher damping factor and increased power have brought the sonic definition to very realistic levels. The music is alive and well. My speakers are vintage JBL C50's.

Similar Products Used: The crown amp must be mounted remotely, mine is in the basement because of the fans. (It was designed for commercial use).
OVERALL
RATING
5
VALUE
RATING
4
BrianL   Audio Enthusiast [May 29, 2002]
Strength:

Versitile, excellent musical listener, robust.

Weakness:

Obviously, after 30 years, some component upgrades are warranted to get the most out of this unit.

I see my original review has been deleted. Anyway, this is an update of it. A few months ago, my C28 started to evidence channel imbalance. I delivered it for repairs with only the instructions to bing it back to original specifications and update the inputs/outputs to gold. Now, just prior to this problem the unit has never seen service during my ownership. The bill was about $200US and included changing out a multitude of capacitors and the connectors. After letting it burn in for a couple of weeks, I decided to listen and was amazed at the difference in sound. This was almost a totally different sounding preamp. Detail, resolution, bass tightness, strings, vocals - almost everything was greatly improved. MOre over, the big issue related to the C28 vs the C29, that of noise threshold is no longer an issue for me. On phono, wide open into my MC2105 feeding my Klipsch Heresy IIs, there is only the faintest of rushing. My ear must be less than about 2 feet to hear it. This is 105 watts into a set of speakers that are something like 96db efficient. At levels I play my music at there is dead silence. I don't know whether the difference is in the caps replaced or the jacks or both but, the combination put this preamp from me way in front of even my tube MX110 preamp. For those with C28s, you may want to look at updating them.

Similar Products Used: Audio Research, Marantz, AVA, Dyna, McIntosh, Fisher, Scott, Conrad, Krell
OVERALL
RATING
5
VALUE
RATING
5
Richard Sherman   Audiophile [Dec 05, 2001]
Strength:

Build quality, feature rich, thoroughbred vintage audiophile component.

Weakness:

Evidence of poor passive component parts quality typical of that era. Noisy Ceramic Disk and Electrolytic Capacitors used in critical signal paths. Over time sonic degradation will occur. Carbon Composition resistors throughout the unit can eventually drift in value and also affect performance.

I purchased this unit used with no wood cabinet. Initially the C-28 had a loose bus ground wire terminal. When tightened the unit stabilized and performed quite well.

When compared to other solid state preamplifiers, it's only flaw has to do with the fact that McIntosh used many Ceramic Disk Capacitors in the signal path. It is a well known fact that over time, ceramic disk capacitors will drift, magnetize and even transform and change their dielectric chemical properties resulting in poor sonic performance.

The sound of the C-28 can be described as dry and analytical but very precise and clear. In comparing with Headphones between the source CD, Reel, Cassette, etc. and the C-28 Output, a slight grain seems to be added to the music. I can attribute this upper frequency grain to the degradation of the components and maybe some noisy transistors that an upgrade can make right.

The C-28 controls are all precise and noise free. The Preamplifier is extremelly attractive and solidly built. One look inside and the First-Class McIntosh craftmanship is evident throughout. McIntosh factory craftsmen and craftswoman initials and dates are visible throughout the interior of the C-28 giving a real testament to that McIntosh pride and workmanship.

The C-28 features Discrete Bass and Treble Tone Controls and a complete set of Input and Output level adjustments on the top panel, including a Headphone and Center Channel level. The McIntosh C-28 Preamplifier also offers two sets of RCA Outputs with a combined derived Center Channel RCA on each. The McIntosh C-28 also features a separate Line Level Output and a full set of Source Input connections: Phono 1, Phono 2, Tape 1, Tape 2, Tuner and Aux. It also features a High Filter, a Low Filter for those warped LP's and a tone contour switch with Presence, Normal and Loudness. You can switch power to an amplifier via a top mounted switch. Note that the AC sockets do not accept the modern polarized types. Both AC prongs must be the small (Hot Lead) vintage types.

The McIntosh C-28 Stereo Preamplifier proves that McIntosh was and still is at the cutting edge of Audio technology as many of the features found in the C-28 are relevant in today's Multi-Channel, separate Sub-Woofer Home Theater environments.

I have to reiterate that the passive components that make up these state of the art Vintage Pieces of equipment do not all stand the test of time. Back in the 70's, Ceramic Disk capacitors were commonly used in most production environments. Silver Mica was considered an expensive alternative back then. The Ceramic Disk Capacitors do not even appear in their factory service manuals parts list, I checked my original copy. Back then, Engineers probably assumed that these capacitors never go bad. Ceramic Disk capacitors, more so that drifting carbon composition resistors, always degrade over time affecting both the sound quality and possibly the longevity of the component if high voltages are present and severe arcing occurs.

The only thing that I could suggest to improve the performance of the C-28 to better-than-new is to have a competent technician upgrade the Electrolytic Capacitors that form part of all the signal path's to the newer Black Gate or ELNA Cerafine types. These new electrolytic capacitors are the state of the art reference and I could not see why one would not use them as sonic upgrades, unless originality is more important than sound quality for some collectors of Vintage Gear. I would also hunt for carbon composition resistors that have drifted in value, perform a final voltage check on all of the Power Supply sections and change all of the Ceramic Disk capacitors to tested and matched Silver Mica types.

C-28 Preamplifiers are state of the art components that offer reliability and excellent long term performance. Upgraded versions with better components offer dramatically better sound quality that can often compare to modern components costing several hundreds more.

Similar Products Used: Mcintosh is in a class of it's own.
OVERALL
RATING
4
VALUE
RATING
5
J P   Audio Enthusiast [Jan 07, 2002]
Strength:

"McIntosh". good looking(blue face). used price is getting higher

Weakness:

Old. Modest sound, easy to break face glass(as other Mcs)

I had had this preamp for a while. But the only reason I kept it was its attractive appearance. I am sure it was the one of the best preamp when it was produced. It still produces clean and nice sound. but nowadays, there are many preamps out there which produce sound as good as C-28 with lower used prices. I compared C-28 with Onkyo P-304, and found P-304 has little bit better sound with both tube amps(Art Jota and Anthem Amp 1) and SS amp(B&K 202). I also compared it with Mod Squad line drive(McCormack) and C-28 was not even close.
If you are just fine with modest sound and want something good looking, go for it. But it is definitely not for a stereophiles.
My system when I have C-28
speakers: Apogee Centaur(and Klipsch Heresy for short time)
main amp : Art Jota tube amp
CD player: Nakamichi OMS-7

Similar Products Used: many
OVERALL
RATING
3
VALUE
RATING
3
Pete   Audio Enthusiast [Sep 17, 2001]
Strength:

Build quality. Resale value. Looks.

Weakness:

Tons of features that you will never use. Probally useful when new and tape was king.

I was running a Jolida 603 CD right into a pair of strapped Mac 240's. Because the Jolida had a gain control I felt that I did not need a preamp. Well I decided to get back into 33's and was looking for an inexpensive phono stage/preamp.
This C28 came along and decided to put it into the mix. I still haven’t hooked a turntable up but the great news is that I can now boost my B&W Nautilus 805's a tad. Not much, but a click here and there really makes an improvement. I guess my positive post relates more to the combination of gear that I have than the preamp, but it works and I am very pleased.

Similar Products Used: Parasound - Adcom
OVERALL
RATING
5
VALUE
RATING
5
Jordan   an Audio Enthusiast [Nov 24, 1998]

I bought this about a year ago to simplify my set-up, and get a bit of extra cash. The C-28 replaced a PS Audio line stage, Audio Alchemy phono stage and a Counterpoint tube MC pre-preamplifier. The AA phono stage was being run (with a DDE v1.1 DAC) off a PS-2 power supply (their largest) and the cables were all good quality. This piece had a new glass front panel, and a new (maybe even upgraded) volume control put in by McIntosh for the previous owner. For the money I paid (~$300 including a speaker relay and wood case), nothing else seemed to be worthwhile, and my wife loves the look of the old McIntosh gear (that goes a long way).
The McIntosh is full of features, think of it like the Carver of the 1970's. I was told the phono stage was going to be inadequate, although it has a nice 62db of gain, and the sound would be harsh and transistor-like (whatever that means). At the time it seemed this would be a 'temporary' downgrade.

Bottom line: My assumptions couldn't have been more wrong. The McIntosh mated perfectly with my amp (a nicely modified/upgraded Conrad-Johnson MV-75A1), and speakers (Snell EIII). Improvements in resolution, and soundstage were the most immediate changes. The phono section was more than enough for a 1.5mV Grado Signature model MC cartridge, and a MM Sumiko cartridge (the Sumiko has since been retired) and far more engaging compared to the AA + Counterpoint.

The used market is a tremendous resource for excellent equipment at very low prices for all us budgetary challenged music lovers. McIntosh gear is some of the most well built and reliable on the market, and their solid state gear is readily available. The C-28 is a stately piece in appearance, and its sound is incredibly pleasing. However, I think the key here is system synergy. Components designed and built recently may employ engineering that does not work well with older designs, or vice versa. But I still think for $300 (or up to $400, which it seems most are asking for C-28) you are unwise to jump into buying new. Keep in mind, anything "new" you do buy will depreciate quickly; a McIntosh will probably be still worth close to what you paid if not more in 5-10 years. Sonically, I haven't heard anything that compares, and I would bet that in the under $1000 market (new gear), you will have a hard time finding a clear winner over the C-28. At this price point I feel it deserves 5 stars.


The used market is a tremendous resource for excellent equipment at very low prices, for all us budjetary challeged music lovers. McIntosh gear is some of the most well built and reliable on the market, and their solid state gear is readily avaible. The C-28 is a stately piece in appearance, and its sound is incredibly pleasing. I'm sure after listening to a Pass Aleph P, Threshold, or Conrad-Johnson preamp (or all the other over $1300 preamps out there) you could pick apart the C-28 all night, but at this price point I would give it 5 stars based on sound quality and the undeniable truth that what you pay for it will be what you sell it for. (Its competition would be perhaps: B&K, Rotel, PS Audio, the Audio Alchemy DLC + VAC setup, and maybe even NAD.)

OVERALL
RATING
5
VALUE
RATING
Showing 1-6 of 6  

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