Type of output transformer to use.

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by EdMan57, Jan 29, 2008.

  1. EdMan57

    EdMan57 Member

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    I'm having a dual EL34 powered 1-12 combo built in the next two months and want to know what you guys suggest as far as output transformers go.The builder thinks that I would like the amp better built with an OT with less headroom and quicker breakup.He knows that I play about 80-85% at lower levels with maybe 6 or 7 gigs a year.The amp will have a clean and overdrive channel that will do fairly high gain.Would a tranny with more headroom and punchier dynamics still work for bedroom jams?Any thoughts or suggestions are most appreciated.Btw,the amp will use Heyboer transformers,due to the good cost/performance/quality ratio.

    Ed
     
  2. EdMan57

    EdMan57 Member

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    Would the punchier and higher headroom OT also affect the amp's feel and response at quieter bedroom settings?Or would the amp's preamp section give much more of the amp's tone and feel at such levels?...Thanks.

    Ed
     
  3. SatelliteAmps

    SatelliteAmps Member

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    Different OT's will sound different at all volume levels. Not exactly sure what the builder means by a punchier transformer. A lot of those types of things can be controlled in the circuit design, rather than just the OT.
     
  4. TheAmpNerd

    TheAmpNerd Member

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    Work best with whatever you and your tech work out.

    Anything else is just guesswork here on the net.

    If you and your tech can't work it out then find
    another tech. The worst thing is posting recommendations
    from your tech here, second guessing him, etc etc.

    Unless there are red flags....but we don't know all
    that you and your tech discussed etc.

    There is nothing worse as a tech then having
    someone come say, well i posted such and such
    on the net and they said C & D not A & B.

    Next time I'm going to say great, take your amp back,
    pay me for the work that I've done and give it
    to your net friends and let them do C & D.






     
  5. EdMan57

    EdMan57 Member

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    He says that the Marshall 45 watt spec output transformers that he favors for his dual EL34 circuit designs come in both lower [early to distort] and higher headroom [punchier and more dynamic] versions from the manufacturer.

    Ed
     
  6. donnyjaguar

    donnyjaguar Member

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    This can generally be determined by the shipping weight. :)
    I'm of the opinion that bigger is better.
     
  7. rooster

    rooster Member

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    Those are the ones from Weber, and there's a chance that Heyboer builds them; you should e-mail Ted and find out whether the ones he has listed under the Weber brand are Heyboers or who actually makes them. Either way, they are a good price/performance value.

    With either OT, unless you've got that amp cranked pretty high, they are going to be fairly similar. Once you get the output tubes clipping (or, as it may be, the PI clipping and the output tubes passing that along, big discussion years gone by about THAT one), you'll start getting the difference between them. Personally, I'd go for the more punchy one and design the circuit for the amount of desired compression. But that's me.

    rooster.
     
  8. EdMan57

    EdMan57 Member

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    Thanks rooster,will do.

    :AOK


    Ed
     
  9. phsyconoodler

    phsyconoodler Member

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    Those are not Heyboer,but offshore stuff at weber.He lists the Heyboers as an upgrade and they are just that.I would not recommend those offshore transformers as they don't sound anywhere near as good as Heyboers do.
    A transformer for a JTm45 will have a 6.6k primary if it's built right,and is better suited to KT66's or 5881's like the JTM45 came with originally.
    Go for the Heyboer and don't go for that 'breaks up earlier' crap.They sound horrible.
    Get an OT that has a 3.4k primary,designed for EL34s.
     

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