5f1 Champ - OT swap?

Discussion in 'Amp Central Station' started by caspersvapors, Jul 8, 2019.

  1. caspersvapors

    caspersvapors Tele-Meister

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    I have a 5f1 build outfitted with the Classictone 40-18115 output transformer:

    http://www.classictone.net/40-18115.html


    I noticed that Classictone also sells this even smaller OT, which is reverse engineered from an actual Tweed Champ OT:

    http://www.classictone.net/40-18110.html

    If I were to swap to the 40-18110, how significant would the change in headroom and overall distortion on tap be? Would it also make the bass farty?

    Thanks!
     
  2. Junior Little

    Junior Little Tele-Meister

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    I can't speak to the 18115, but the 18110 is pretty decent. I'm running it in a Champ clone-ish and I like it. Crank up the amp and it gets darn near Marshall-ish in tone. But, this is through a Vintage47 6x9 speaker, so...
    The tone controls on the Tele and the Strat are needed, but I dig it.
    I'm using the ClassicTone 18031 in a 5F2 clone-ish and I absolutely love the tone from that amp. It's the Angela Instrument version of the Princeton and let me tell you: I wouldn't trade that amp for love or money. A super-charged Princeton is the checker, brother.
    YMMV
    Nevertheless, try it. You might like it.
    Good luck!
     
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  3. tubedood

    tubedood Tele-Meister

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    I agree Junior Little. I just finished up a 5F2-A build.. still wrapping up the biasing. A few simple tone mods and an alnico 10 inch speaker. It sounds great.

    I am sure the OP will love his 5F1! I am not familiar with the output transformer hes going with... I went with a big Allen Amplifiers TO-11S. Its big enough to use an EL-34 on a bigger project someday.
     
  4. King Fan

    King Fan Friend of Leo's Ad Free Member

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    Just read a debate about this on one of those tech-infested forums.

    The 40-18110 is *smaller* than the 40-18115. In fact they call it their "Tiny-Sized" Champ OT. The 15 has 8k winding on the primary, nominal 5W. The 10 is 17k winding, also nominal 5W. Both of course 4 ohms.

    In theory the 10 is the original spec,,, How does that affect the sound? Time to build one with both, on a switch. Who's game?
     
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  5. dan40

    dan40 Tele-Afflicted Silver Supporter

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    I have also seen that model and wondered what it would sound like. I was curious if perhaps that is the OT used on the first series of Champs when they were using the 6" speakers, Maybe Fender stepped up to the more well known OT when they switched to the 8" speakers in the Champs.
     
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  6. tubedood

    tubedood Tele-Meister

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    If you do get the lil '10 transformer do tell us how it sounds!
     
  7. tweedman2001

    tweedman2001 Tele-Afflicted

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    I have also built a 5F1 with the 10 tranny and a vintage 8" speaker. I have not compared it with a 15 build but I can say that it sounded very similar to my original 5F1. That was what I was going for as the 10 is supposed to be close to original.
     
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  8. King Fan

    King Fan Friend of Leo's Ad Free Member

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    I'm not smart enough to figure the tone effects of 17K reflecting 4 ohms, and in addition the 'tiny' form factor suggests a small stack. Does this thing saturate super early? Does it cut low frequencies? Dunno...
     
  9. Snfoilhat

    Snfoilhat Tele-Afflicted

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    If you have the standard 8k:4R transformer and want to get a quick impression of what the 17k:4R transformer is going to sound like, try plugging a 8 ohm speaker (the same model as the 4 ohm if it's available) into your stock OT.

    8k:4R --> 16k:8R
     
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  10. intensely calm

    intensely calm Tele-Meister

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    Just to throw in another option -
    I used the ClassicTone 40-18030 in my 5F1 build

    http://www.classictone.net/40-18030.html

    It has the same footprint at the 18115, but has 4Ω and 8Ω output options (more speaker options).
    As for headroom difference, I can't technically say.
    Speaker farty, yes it will do that.

    I've read here/somewhere about changing filter cap values to help remedy, or lessen the "farty".
    Others will have to chime in on that however, as I have not attempted such mods.
    I'm currently using a Jensen Special Design 8" 4Ω Ceramic, which may be enhancing the farty at volume.

    Screen Shot 2019-09-06 at 10.34.00 AM.png

    I have just assembled an L-Pad attenuator box which allows the amp to be cranked up, but at lower volume output to the speaker.
    Kinda nice so far, my dog approves.
     
  11. caspersvapors

    caspersvapors Tele-Meister

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    my 5f1 with the 40-18115 and a cva8 speaker isnt farty at all
     
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