Wednesday, June 19, 2024

Matching impedance Pre and Power amp

Viewing 2 reply threads
  • Author
    • #195273
      William TurnerWilliam Turner

      I own a Mcintosh MC302 stereo power amp, and i’ve found a Audio Research LS27 pre amp.  Question is how do i know if they’ll play together so to speak??   I just know from experience it doesn’t always work to mix and match pre and powers.

      Mcintosh  has 22.000 ohm balanced input

      ARC LS27

      Output Impedance: 700 ohms Balanced, 350 ohms SE Main (2), 20K ohms minimum load and 2000pF maximum capacitance. Outputs (3): 2 Main, 1 Record (XLR and RCA connectors).

      Gain: Main output: Selectable for each input: 24dB, 18dB, 12dB Balanced output. (18dB, 12dB, 6dB SE output.) Record output: 0dB (Processor input: 0dB balanced).



    • #195677
      Alan GreenAlan Green

      Neophyte here William. Can’t help but following and hope others will chime in.

    • #197238

      I once looked into the relation between input and output impedance. The higher the input impedance the easier it will be to drive. I’ve tested devices up to 200K Ohms. For example a Classé CP800 has a 100K input impedance and a CP700 had 200K input impedance. And a 100 Ohm output impedance. This means the current that is needed to drive the CP700 is only 50% for what is needed for the CP800. Poweramps and subwoofers are most of the time somewhere in the range of 15K to 50K Ohms.

      Now you can ask yourself what the difference is. Well this depends on the unit that’s driving. Just make sure that the unit is able to drive lower impedance than the unit that must be driven. Besides this on higher input impedances I would use even better cables, because the signal with less current is most logical more easy to be influenced by electromagnetic fields.

      How they will sound together is depended on far more parameters

      Hope this helps!

Viewing 2 reply threads
  • You must be logged in to reply to this topic.