Image Credit: Starsky on eBay

Mcintosh MC-2505 Power Amplifier (1967)

The McIntosh MC2505 is a solid state power amplifier with a maximum power output  50 watts per channel operating simultaneously, into 4 ohm, 8 ohm, or 16 ohm loads.

"When introduced in 1967 the McIntosh MC-2505 was a revolutionary amp in many respects and served as the blueprint for all future McIntosh amps to come. Not only was it McIntosh’s first solid state amp ever, it was also their first to have a full glass panel faceplate, precision calibrated output level meters, the panloc mounting system, and it was the 1st sold state amp to incorporate McIntosh’s famed Unity Coupled Autoformer for full rated output at 4,8, or 16 Ohm impedance."

For Sale:   This Mcintosh C-20 is currently for sale on eBay via seller Starsky. Get your bids in now, auction ends June 10, 2014.

Specifications

Power output: 50 watts per channel into 8Ω (stereo)

Frequency response: 20Hz to 20kHz

Total harmonic distortion: 0.25%

Damping factor: 10

Input sensitivity: 0.5V

Signal to noise ratio: 90dB

Speaker load impedance: 4Ω to 16Ω

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Image Credit: Starsky on eBay

McIntosh C-20 Stereo Compensator / Preamplifier (1959-1963)

Retail price $269.00 in 1959.

"Simplicity, flexibility, and beauty have been integrated by careful engineering and design in the McIntosh C-20 Stereo Compensator. The greatest listening pleasure in stereo or monophonic reproduction is assured as a result of over a year of careful and diligent research in hte requirements of a new preamplifier designed for stereo. Full stereo flexibility has been provided plus built in protection for your investment in monophonic records. McIntosh has designed in the C-20 Stereo Compensator the necessary features required to give the finest monophonic reproduction the keenest listener may require. Complete satisfaction is yours in monophonic and stereophonic with the McIntosh C-20 Stereo Compensator."

For Sale:   This Mcintosh C-20 is currently for sale on eBay via seller Starsky. Get your bids in now, auction ends April 23, 2014.

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All images Credit: eBay Seller "Starsky10"

Mcintosh C28 Preamplifier  (1970-1978)

The McIntosh C28 is a high quality stereo pre-amplifier made in from the early to late 1970's  Each channel of the C28 consists of four parts, a low level amplifier, high level amplifier, active filters and headphone amplifier.

Specs:

Response 20-20kHz (+0 -0.5dB). Distortion 0.1%. Noise and hum -90dB aux, -78dB phono

Size 5-7/16"H, 16"W and 13"D behind panel. Weight 25 lb. Sold from 1970-1978. Last retail price $649.00

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Mcintosh C26 Preamplifier (1967, $449 original MSRP)

In 1967, I began design of the C26 preamp. It replaced the C24. This was the first preamplifier to have an all glass front panel, which matched the new MC 2505 power amplifier. It was assigned a project number of P 216. The requirements had already been determined by Gordon Gow, based on his marketing research.  Some of the circuitry was already being used in the MAC 1700 receiver, but I revised several features and added several new ones.

Response: +0 -0.5 dB 20 to 20,000Hz
Distortion: less than 0.1%
Input sensitivity: 2.0mV phono. 0.25V aux, tape and tuner

Panloc mounting
Front panel: glass, gold/teal, illuminated
Size: 5-7/16” high, 16” wide and 13” deep
Weight: 18 lb.
Sold from 1968 to 1977
Last retail price: $449.00

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Mcintosh Mac 1900 Stereo Receiver (1973-1978. Last retail price $949.00)

One of Mcintosh's finest solid state receivers.  The Mac 1900 produces 55 watts per channel into 4 or 8 ohms with a damping factor of 50.

Tech:
Solid State.

55w/ch into 4 or 8 ohms. Response 20-20kHz (+0.5 -0.5dB). Distortion .2%. Noise and hum pwr amp -95dB, aux -90dB, phono -76dB. Damping factor 50. Input impedance: pwr amp 100k, aux 250k, phono 47k. Input sensitivity: pwr amp 2.5V, aux 0.25V, phono 2.0mV. Tone controls: bass and treble. +16 to -16dB. LF filter 50Hz at 12dB/octave. HF filter 7kHz at 12dB/octave.

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Mcintosh MA-5100 Integrated Amplifier (1966-1972, 449 USD)

A nice early solid-state integrated amplifier from McIntosh.  Conservatively rated at 45 watts per channel, the MA-5100 was launched in 1966 and produced for 6 years until 1972.  It's final retail price clocked in at $449.

Check out the full specs after the break.

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[Image Credit:  eBay Seller 'Starsky'. Visit Starsky's eBay Store to see his current vintage audio auctions]

Mcintosh MC240 Tube Amplifier (Orig. MSRP: $288, 1960-1969)

Technical specifications

• Stereophonic power amplifier
• Power output: 40w/channel in stereo modo. 80 watts in mono.
• Class: AB
• Power tubes: Philips ECG 7581A (x4)
• Preamp tubes: Sovtek 12AX7LPS (x3), National 12AU7 (x2) , 12BH7 (x2). Diode rectification.

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