MC30 Restoration - Filter Caps

Discussion in 'McIntosh Audio' started by sjfloat, May 15, 2017.


What's the recommended way to replace filter caps?

  1. Buy modern replica (ala Authenticap, etc)

  2. Stuff the original cans

    0 vote(s)
  3. Disconnect and leave cans, install new axials underneath

    0 vote(s)
  4. Other...

  1. sjfloat

    sjfloat Super Member

    Greater Pittsburgh, PA
    What's the best practice for filter cap replacement?

    I'm also considering an incremental approach, e.g., using axials inside as part of getting it functional and then buying new cans later.
    Last edited: May 15, 2017


    Please register to disable this ad.

  2. MACKIE1975

    MACKIE1975 Well-Known Member

    Don't get electrocute. "Keep one hand in pocket" (I think c_dk said this)
  3. SilverTpt999

    SilverTpt999 Active Member

    Not sure about the MC30s, but for the MC60s I bought a drop-in which had only two sections instead of 4, but they were larger in capacitance; used them to add a little to the power supply. One of the sections was dedicated to power the C8 preamp, and I never will need that ability, so I left it out. That left me one section short, and I fabbed a bracket to hold a modern axial electrolytic under the chassis.

    The cosmetics of the replaced cap is perfect, the amp performs even better, and it looks neat underneath. Cheaper than Authenticap.

    But if you aren't reasonably confident with tweaking a circuit slightly and safely, Authenticaps are the way to go. I don't think re-stuffing is a really viable option, and simply disconnecting the originals could set you up for a messy leak later on.
    x3workshop likes this.
  4. x3workshop

    x3workshop AK Subscriber Subscriber

    Don't do double work. Just do a proper rebuild. Authenticap 80/40/30/20 multisection is the way to go with MC30's. Virtually the same size as original. Use the 40uF for C12A and tie the 80 & 30 sections together for C12B and the 20uF for C12C. The slight increase in capacitance down the line does wonders for bass performance in that amp. The C12C is for the preamp power plug and isn't necessary, but I use it in case the next owner of these amps wants to use it. My 2ยข
    Last edited: May 17, 2017
    Bill Ferris and CDinMB like this.

Share This Page