Tung-Sol 6550 Type Three now installed in "Harry Gates" Amp

Discussion in 'Tube Audio' started by kcline, Feb 14, 2018.

  1. kcline

    kcline Tube Audio Collector Subscriber

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    DSCN0424.JPG DSCN0425.JPG I have now around 200 HRS on the "Harry Gates Memorial" amp. Have been running a set of Sovtek 6550,s, today changed to Tung-Sol type 3 6550. These are all marked Raytheon Adjusting bias to each tube to 50mA. Hope to listen to this tonight after work. If I cannot tell any difference I will put the Sovtek,s back in. Input tubes are Raytheon Black plate 6201 Driver tubes are 1950's Syl 12AT7,s
     
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  2. kcline

    kcline Tube Audio Collector Subscriber

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    Something I keep forgetting Did any one here know Harry Gates? He lived in Goldsboro NC died about 9 or 10 years ago was well known to radio collectors and was very much into Ham radio, had an all Collins set up
     
  3. primosounds

    primosounds SE KT120 w/ 6J5G drivers. LCLC ps + 2 x 5ar4 Subscriber

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    Interesting amp. What kind of trannys are used in it? And what is the tube in the middle back for? I am guessing voltage regulation since it doesn't look like a rectifier.
     
  4. kcline

    kcline Tube Audio Collector Subscriber

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    The "Harry Gates Memorial" amp has the iron from a ARC Dual 75 amp and has Lundahl input and driver transformers DSCN0329.JPG you can see them at the bottom of the picture. This pic is not the final version that I am using. The 6550 in the back is a Sovtek it is for screen regulation Amp has no caps in audio and no feedback
     
  5. kcline

    kcline Tube Audio Collector Subscriber

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    The Tung-Sol's are staying in. Playing the SACD of The Flying Burrito Bros "The Gilded Palace of Sin" the 1st track has the vocals on the outside edge of both speakers, sounds thin and narrow with Sovteks in place. With the TG's sound is fuller wider and more 3d sounding. Hope to play more this weekend.
     
  6. kcline

    kcline Tube Audio Collector Subscriber

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    DSCN0428.JPG DSCN0430.JPG DSCN0429.JPG Here are some more pictures of the Harry Gates amp and the Paoli modded Dynaco MK-3. Both these were built by the late Harry Gates, the "Paoli" is not a true Paoli, Harry modded it with the early Triode Board which I have running RCA 12BH7 and Telefunken 12AU7. The finals are Tung-Sol 6550 type 1,s
     

     

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  7. dcgillespie

    dcgillespie Fisher SA-100 Clone Subscriber

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    Neat amp! I haven't heard of Harry, but his design certainly looks interesting. Like (apparently) Harry, I wouldn't miss the overly complex front end design of the ARC Dual 75, but at least it looks like he (Harry) did retain the push-pull cathode feedback in the output stage, which is a good thing. Pure pentodes with no feedback at all? Wooof!

    Neat stuff!

    Dave
     
  8. kcline

    kcline Tube Audio Collector Subscriber

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    DSCN0786.JPG Here is picture of the Lundahl transformers. This is a before picture as done by Harry Gates
     
  9. kcline

    kcline Tube Audio Collector Subscriber

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    DSCN0438.JPG Today I looked thru my 6550 tube collection and found a nice quad of TG type ones,flashing on top only black solid beam forming plates placed in amp and ran them up to 48mA on each tube after one hour all is well holding at 48mA hope to play more over the weekend
     

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