How to wire separate 8 Ohm and 16 Ohm speaker input jacks?

Discussion in 'Amp Tech Center' started by dragonfly66, Apr 20, 2019.

  1. dragonfly66

    dragonfly66 Friend of Leo's Silver Supporter

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    I have an amp (5E3) that has an OT with taps for 4, 8, 16 Ohms. I have 8 and 16 Ohm speakers and would like the option of using either in this amp. The amp already has two speaker inputs so I don't need to drill any new holes. I want to wire the two speaker inputs where one is for 8 Ohms and the other is for 16 Ohms. I do not want to use both inputs at the same time. The intent is to use one 8 Ohm speaker or one 16 Ohm speaker that is installed in the amp.

    I have seen examples of multi-tap setups but not like what I want. I am not certain what jacks to get or how to wired them. All of the examples I've seen have been for parallel connection of two input jacks, which is not what I want. So if you anyone can point me in the right direction I'd be grateful.
     
  2. Bendyha

    Bendyha Tele-Afflicted Silver Supporter

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    upload_2019-4-20_9-31-30.png

    For one, or, the other, you can make it completely simple.
    I prefer to use output jacks that are isolated from the chassis, and the cliff jack would be my normal choice. This of course is a non-american style, so for a 5E3 amp you might go for the basic switchcraft style jack, either bolting it straight onto the chassis for a chassis grounding - old school, or add isolating (insulating / shoulder) washers to the two jacks, and running a dadicated ground wire from the ring terminal tabs to where the OT is also grounded.
     
    Last edited: Apr 20, 2019
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  3. Bendyha

    Bendyha Tele-Afflicted Silver Supporter

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    Here is the more visual layout of the wireing, the jacks you need and the pairs of isolating washers for the jacks. The colours of the appropriate transformer taps on you OT are not known to me, so substitute as needs be.

    upload_2019-4-20_12-42-25.png
     
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  4. ecoast

    ecoast Tele-Holic

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    so isolated jacks, but should they be shorting or non-shorting?
    shorting, I would guess?
     
  5. schmee

    schmee Poster Extraordinaire

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    Connect the NFB to the amps normal output leg (8 ohm)
    Non shorting I would think? You dont want one tap grounding while you are using the other tap right?
    I use a switch on the hot leads when I do multitaps.
     
  6. dragonfly66

    dragonfly66 Friend of Leo's Silver Supporter

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    Thank you @Bendyha this is perfect.

    Here is what the two jacks look like now. The green is 8 Ohms and orange is 4 Ohms. Looks like I'll need to get new jacks cause the installed ones appear to have more lugs/layers.

    [​IMG]
     
  7. dragonfly66

    dragonfly66 Friend of Leo's Silver Supporter

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    Do you have a diagram/layout (not schematic) of how the switch and jack are wired for multiple taps?
     
  8. telemnemonics

    telemnemonics Doctor of Teleocity

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    I prefer a switch when the jacks are hard to see, and in general.
    You would just pull the hot wire from the center lug on a speaker jack and connect it to one of the DPST sides of the switch, then from there to the (changed to a single jack) jack.
    Same with the the other speaker jack to the other side of the switch, so it breaks the connection of one tap to the jack and connects the jack to the other tap, but both connect to the same jack. Then your switch takes one of those holes and you toss the second output jack in the parts bin.

    But you've wired it up now and if it works for you no need to change it.
    Also my description might be confusing and not very helpful!

    I'm going to presume that there are different switches lug pinout, so a diagram/ layout might be wrong if the switch you get has a different pinout.
    DPDT has two separate circuits that either make or break, so six poles, and only one throw with two on positions.

    Hope i got all that right!
     
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  9. schmee

    schmee Poster Extraordinaire

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    [​IMG]
     
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  10. telemnemonics

    telemnemonics Doctor of Teleocity

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    This makes sense, for some reason I was thinking of keeping the two transformer taps on separate sides of a DPST switch, but here it's on a SPST switch which is more correct.
    Same idea as I posted above, with no drawing though.
    I would also have put the switch in one of the jack holes since space is limited, but that's a separate issues from the actual wiring.
     
  11. schmee

    schmee Poster Extraordinaire

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    Yeah, the trouble is, most big Carling style switches you have to ream out the jack hole as it's too small. SO I usually end up in the old ground switch hole on Fenders...
     
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  12. dragonfly66

    dragonfly66 Friend of Leo's Silver Supporter

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    Thank you @schmee! I may do the switch instead and use one switch and one jack, putting the switch in one of the jack holes as suggested. I like it better than two jacks.
     
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