I modded my Fuchs mod Music Man RD50

Discussion in 'Amps and Cabs' started by rhythmrocker, Apr 21, 2015.

  1. rhythmrocker

    rhythmrocker 1966 Battle of the Bands Supporting Member

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    Well sort of. I sent my RD50 head to Andy to get modded into his ODS offering.
    When I first got it back, it had some heating issues. This is probably the smallest head the Andy is able to put his mod into because everything is such a tight fit in the chassis. Anyways, Andy addressed the heating issue and assured me that, even the power transformer got hot, these guys never fail. I did some research and a guy at Mercury told me that one rule of thumb is that if you could your finger on the OT and keep them there for 4 seconds plus, then it would be fine. And that’s exactly how long I could hold my finger on it. I borrowed a heat gauge and measured the PT at 122.3-125.00 degree Fahrenheit.
    Despite other reassurances that I received that the amp would be “ok”, I want to create a buffer of safety as I didn’t want this thing to fail on me.
    So I did 2 things: 1) I removed the front cover and 2) installed a fan (~21 CFM).
    Here are a few details on these two things:
    1) I found an aluminum grill on eBay. It’s used to replace grills on cars. A 6” high by 36” long piece cost me about 16.00. So I matched the thickness of the OEM front plate (the one with the logos) with the plywood I bought for $4; routed it with a center brace; painted the plywood with Plastic-Dip; stapled the grill to the back of the routed plywood, reinstalled it. Only took a few hours to do the whole thing with the help of my friend Dean. Now I have AIR FLOW, or at least, a way for the hot air in that closed up head shell to get out more easily.
    2) I bought a Weber mod fan kit and some small L-brackets (4) with #8 bolts and hardware. I attached (actually my friend Ron Ott did this leg of the project cause he is, well, my friend) the painted L-brackets (love the Plastic-Dip) to the fan with star washers and self-locking nuts. I had also purchased two of those trailer hook-up wires for lights. That way one hook-up wire could be soldered to the heater connectors as per Andy’s instructions, exiting the chassis downward) and the second wire set could be attached to the little circuit board that comes with the mod kit. This way, I could unplug the fan if necessary, i.e., if and when the fan goes bad. The soldering in the chassis was a breeze as the traces for the heaters were right at the edge of the circuit board. I mounted the fan inside the head shell so that the air would blow onto the PT (as suggested by Ron – I mean after all, he builds amps and is a retired physicist!). The reverb can was zip-tied and I used Velcro glued to the bottom of the bag and the chassis and moved everything over give some room under the fan for air flow. Ron then mounted the board to the bottom corner of the chassis so I could get to it through the back panel if I wanted to change the speed of the fan viz a viz that black switch. Note: the little board with the capacitors on it has to be assembled). Strain-reliefs were used in the chassis and near the fan board to hold the wires in place for unplugging purposes.
    Now you see in the later picture, using the same temp gauge, the temperature has gone down a whopping 30 degrees! Note that the amp was fired up and full on for about an hour, using a signal generator through the front input of the amp. Junior, the house dog, was supervising each leg of the entire project.
    There you have it folks. This was fun and now I have peace of mind on the heat issue! On to the next “project.”
    The original amp: [​IMG]

    The fan mod after receiving the amp back from Andy:
    [​IMG][​IMG][​IMG][​IMG][​IMG][​IMG][​IMG][​IMG][​IMG][​IMG][​IMG][​IMG]
     
    Last edited: Apr 22, 2015
  2. billyguitar

    billyguitar Member

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    Cool. How does it sound!!!!
     
  3. stratpaulguy86

    stratpaulguy86 Member

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    It sounds "cooler" now, duh!
     
  4. billyguitar

    billyguitar Member

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    Ha!

    Seriously, I have a little Musicman 110RD50 and was thinking about sending it to Fuchs for the ODS mods. I've never heard a Fuchs so I have some questions.
    I know the Overdrive is great but how are the cleans? I have a Redplate that blooms when it's clean. Will this amp do that?
     
  5. stratpaulguy86

    stratpaulguy86 Member

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    Andy Fuch's amps are known for their great cleans. Any good D-Style amp should have cleans that bloom and have great sustain. I wouldn't hesitate sending a Musicman to Andy for his ODS mod. The iron in your amp is fantastic and should be killer for an ODS style amp.
     
  6. billyguitar

    billyguitar Member

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    Great! That's what I wanted to know. Thanks!
     
  7. Fuchsaudio

    Fuchsaudio Member

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    To be safe, I would add a grommet or some heatshrink tubing to the wires where they pass through the hole fuseholder opening. If there is heat and or chafing, you want to make sure those wires don't short to the chassis. Great idea putting the control board and a switch back there too. Glad the amp pleases you and it's even cooler now.... :eeks
     

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