New Filmosound Conversion

Discussion in 'Ampage Area' started by journeyman, May 9, 2021.

  1. journeyman

    journeyman Gretschie

    483
    Aug 20, 2009
    Toronto, Ontario
    My amp tech is Dave Robinson, in Georgetown, Ontario. He's done 63 of the Filmosound conversions so far and his approach as really evolved. This one is a model 285, and has a 6J7 preamp tube. That tube is magic. This is my second one of these and they are both my favorite amps of any that I've owned. The cabinet was designed and built by Derrick Bell at Veteran Guitar Cabinets in Trenton, Ontario. Single 12" speaker, and this one received a master volume after the preamp section.
    IMG_20210508_180718136.jpg IMG_20210508_180734142.jpg
     
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  2. journeyman

    journeyman Gretschie

    483
    Aug 20, 2009
    Toronto, Ontario
    Here's the amp before conversion. The red tube is the British equivalent to the 6J7. I call it the 'robot tube'. Lots of power on tap from the large transformer, as it had to drive the sound and video.
    20210325_164606.jpg
     
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  3. Ricochet

    Ricochet Senior Gretsch-Talker

    Nov 13, 2009
    Monkey Island
    Congrats, looks great!
     
  4. oneforsorrow

    oneforsorrow Synchromatic

    504
    May 15, 2020
    Iowa
    Congrats! Looks very cool. Can we hear it?
     
  5. wabash slim

    wabash slim Gretschified

    Age:
    71
    Feb 10, 2010
    lafayette in
    If he turns it way up, maybe.

    I'm considering doing this with Dad's old Ansco 16mm projector---the one I learned on. Can't get lamps for it anymore, so it's just collecting dust. He got into 16mm while servicing gun cameras on the P-51 and B-17 he was crew chief on. I wound up retiring as a projectionist/stagehand----doing something I learned in first grade.

    Which input do you use? The mike or the film input? As I remember, the film side is really high gain. There's likely an impedance issue with the mike side---it's probably low Z/600 Ohm for the carbon mikes that were so prevalent back in the late '40s.
     
    Last edited: May 9, 2021
    oneforsorrow likes this.
  6. Archtops

    Archtops Synchromatic

    561
    Mar 4, 2021
    SoCal
    That is a very nice looking amp. Great job!
     
  7. journeyman

    journeyman Gretschie

    483
    Aug 20, 2009
    Toronto, Ontario
    On this amp there is only one input jack. Dave basically guts them and rebuilds, using the tubes, sockets, transformers, and chassis. I know some guys use the original guts, or some of them, but this has all new components except for the one mentioned above. Maybe some of the wire, but I'm not a tech so can't say exactly what he does, but I did ask and he said that all resistors, caps, etc. get replaced, and it is his design. On this one he put a master volume after the preamp stage and it works really well when I want some early breakup, or something that is just on the edge. I might get him to do the same with my other Filmo. Most guys build these to sound like mini Marshals of Vox, with lots of gain and punchy upper mids, but Dave went in another direction, more toward Fender tweed era amps, but tightened up the low end.
     
    wabash slim likes this.
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