Second Spin Audio

Buying a used McIntosh MA6100

Seventy watts a side, two phono inputs and that unmistakable McIntosh presence. Here's how to check a used MA6100, which speakers it's rated for, and what to ask before you buy.

Updated

Close-up detail of a McIntosh MA6100 integrated amplifier
Photo: Cocteau, CC BY-SA 2.0 DE, via Wikimedia Commons

At a glance

Type
Stereo integrated amplifier
Rated power
70 W per channel into 8 Ω, 40 W into 16 Ω (both channels driven, 20 Hz–20 kHz)
Rated loads
8 Ω or 16 Ω
Total harmonic distortion
0.2% maximum, 250 mW to rated power
Damping factor
50 at 8 Ω, 100 at 16 Ω
Inputs
Phono 1, Phono 2, tape head, tape, aux, tuner, power amp in
Tone controls
Bass and treble ±16 dB; low and high filters
Weight
15.4 kg

What to check before you pay

  1. Voltage. The specification sheet cited here lists 120 V operation. Check the rating label on the back and make sure the unit matches your mains, or budget for a suitable transformer before you plug anything in.
  2. Speaker impedance. The MA6100 is rated for 8 Ω or 16 Ω speakers. Check the nominal impedance of the speakers you plan to use. 4 Ω speakers sit outside the rated loads, so this is worth settling before you fall for the amp.
  3. Hum and noise. With nothing playing and the volume at zero, put your ear close to each speaker. A faint hiss can be normal for an amplifier this age; loud hum or crackle is not.
  4. Controls. Turn every knob and flick every switch slowly while music plays. Crackle or a channel dropping in and out usually means dirty controls. Often cleanable, but it should be reflected in the price.
  5. Both channels and all inputs. Play a source through each input you need, phono included if you have a turntable, and check that both channels sound the same at a moderate volume.
  6. Lights and front panel. Check that all the front-panel lights work, and look for damage to the panel and knobs. Cosmetic parts for older units can be hard to find, and the front panel is a big part of the appeal.
  7. Service history. Ask whether the unit has been serviced and what was replaced. If the history is unknown, plan for a technician's check before settling in for long listening sessions.

The amp in a nutshell

The MA6100 is a stereo integrated amplifier rated at 70 watts per channel into 8 Ω, or 40 watts into 16 Ω, with both channels driven across the full 20 Hz to 20 kHz band. It’s well equipped for a record collector: two phono inputs, a tape head input, plus tape, aux and tuner inputs, and a power-amp input if you ever want to use it with a separate preamp. Bass and treble give you ±16 dB to play with, and there are low and high filters to tame rumble or hiss from older records.

At 15.4 kg it’s a substantial piece of kit, so plan where it will live before it arrives.

Check it suits your speakers

This is the single most important thing to get right. The rated loads are 8 Ω and 16 Ω. If your speakers are rated at 4 Ω, look for an amplifier rated for that load instead, or ask a technician for advice before buying. It’s far easier to check this now than to discover it after the amp is on your shelf.

Reading a used one before you pay

A used MA6100 can be anything from an untouched original to a fully serviced unit, and the price should reflect which. Ask for the serial number, clear photos of the back panel, a look inside the case if the seller is willing, and a video of it playing with the volume moving up and down. A seller who can show you the receipts from a recent service is offering you real peace of mind.

What to ask the seller

  • Has it been serviced, and by whom? Is there a receipt listing what was done?
  • Does it come with anything else, such as a cabinet or the original manual?
  • Has it been modified in any way?

Manuals

Links open external manual archives or the manufacturer's site. We don't host these files.

Sources