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McIntosh C28

Solid State Stereo Pre Amplifier (1970-75)

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McIntosh C28


The McIntosh C28 is a high quality stereo pre-amplifier.

Each channel of the C28 consists of four parts, a low level amplifier, high level amplifier, active filters and headphone amplifier.

Common regulated power supplies furnish power to both channels.


Frequency response: 20Hz to 20kHz

Total harmonic distortion: 0.1%

Gain: 62dB (MM), 20dB (line)

Input sensitivity: 2.5mV (mic), 2mV (MM), 250mV (line)

Signal to noise ratio: 78dB (MM), 90dB (line)

Output: 250mV (line), 2.5V (Pre out)

Semiconductors: 26 x transistors, 4 x diodes, 2 x bridge rectifiers

Dimensions: 406 x 138 x 381mm

Weight: 11.34kg

Finish: anodized gold and black front panel


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Reviewed Nov 29th, 2017 by Steve Thomas

I ran the service dept for a McIntosh dealer in Cranston RI back in the mid 70's. I serviced many C28 preamps. At the time it was considered the best preamp McIntosh had ever produced. the weak areas were the volume control which got scratchy after a few years of operation and the phono preamp transistors got noisy, they produced a crackling, frying sound. The OEM transistors were a hi gain noise select Siemens. When replacing those xistors pay attention to gain/ noise ratings. .
Now that these are 40+ years old I'd guess they would new a full recap of all the audio and power supply circuits to recapture all the original sound
Even after all these years I still see these for service.

Reviewed Nov 29th, 2017 by RTM

There's a lot of misinformation about this amplifier out there. It is probably better considered a second or maybe third gen SS amplifier and as such shouldn't be thought of as sounding like the earlier SS Mac models. In my experience (one owner examples) they (sonically) resemble the ones that came after more than the ones that came before. Like all Mac gear, it's probably not competitive in the price/performance vs. competitors category. But the Rolex factor (they were there at the forefront of the Art when there were few others for the rest to plink away at) isn't hard to perceive when you own one. I think they're terrific. They're an Old School quality benchmark. The output balance, phono section and tone controls are outstanding. Grab 'em and growl.....



re: C28 Scratchy Volume Control

I’m experiencing the “scratchy” volume control on my 1974 vintage C28 and would appreciate guidance on fixing the problem.

My gear, C28, MC 2100 and Klipsch Heresy speakers are seeing daylight again after many years in storage and the C28 definitely needs some TLC. Also any guesses on cost to get the unit back to spec given the issues mentioned above.

I’m in Maine on the coast about an hour northeast of Portland and was wondering if there was a good repair source in the Boston area and/or further north.

re: C28

I meant to say "preamplifier". This is NOT an integrated amplifer. It is a PREAMPLIFIER and requires a separate power amplifier to function in a traditional High Fidelity application. I apologize for the errors. Regarding the Volume Potentiometer, it was a weak spot in the design. But good pots are out there, you just have to look for them. They can also be rebuilt. I stand by the Five star review...

This website is not affiliated with or sponsored by McIntosh. To purchase C28 spares or accessories, please contact the company via their website or visit an authorised retailer.