Fender twin

Bobby Harris · From: Kentucky, USA

Does anybody know the extra speaker jack to run another speaker does it take 4. Or 8 olm speaker.

Dave Grafe · From: Hudson River Valley NY

The stock Twin Reverb has a 4 ohm output transformer designed to drive a pair of 8 ohm speakers in parallel, i.e a 4 ohm rotal load. The two speaker jacks are wired in parallel, so if you keep the 2x12" internal speakers plugged in any additional speakers will lower the total load impedance below the designed optimum.

For example:

Adding another 4 ohm speaker or cabinet will present a 2 ohm total load to the amp, essentially doubling the current draw through the output tubes and transformer, half of which will go to the extension cabinet.

Adding an 8 ohm speaker will present a slightly higher total load of 2.66 ohms, and the extra speaker cab will only receive 1/3 of the total power.

Either reduces the power available to the 2×12" speakers already in the amp, and if anything is out of phase good luck sorting that out!

Fender amps are very robust so either way it will "work" and some folks do all the time, but knowing how the thing works I don't and I can't recommend it.

Bobby Harris · From: Kentucky, USA

Thanks

Tony Prior · From: Charlotte NC

While Dave ( above) is correct with the technical and theoretical definition, in the real world players who use Twins or other Fender amps , never thought much about it, they just plugged in an extension cab. Fender amps have extremally robust OT's and it is very rare that one blows. It is said that the impedance can go 50% either direction without issues.

One only has to look at vintage photos of bands from the 60's , 70's etc with TWINS on top of 2x12 Fender cabs. They perhaps were supposed to blow but never did ! I personally used a 1970 Twin on top of a Fender 2x12 cab ( plugged in of course) for well over a decade non stop. THEN I pulled the 2x12 speakers from the TWIN Cab and replaced it with an 8 ohm JBL-15. I used that configuration , which was now 8 ohms rather than 4 ohms, for the next 20 years !

When I was servicing Fender Tube Amps, ( the 70's thru around 2010) ) I don't recall every changing a Power or Output Transformer.

My regret is selling that 1970 Fender Twin around 1995, which I bought new from Manny's in NYC for $550. I still have the receipt ! . I was so angry with myself for selling it I ran out and bought a 1971 TWIN and used that for another 15 or more years ! Very Happy

_________________
Emmons L-II , Fender Telecasters, B-Benders , Eastman Mandolin ,
Pro Tools 12 on WIN 7 !
jobless- but not homeless- now retired 9 years

CURRENT MUSIC TRACKS AT > https://tprior2241.wixsite.com/website

Bobby Harris · From: Kentucky, USA

That sounds good I’d say. I pulled my two twelves out and I put a jbl 15 that’s in my Webb amp 4 olm I liked it I took it out put it back in my Webb amp now I’ve got a Travis Troy 12 8 olm. I like it real well do you plug in to the 1 or 2 jack.

Kevin Mincke · From: Farmington, MN (Twin Cities-South Metro) USA

I have run D130’s in both my twins (74 & the 76 being a linear) since they were nearly new. No problems and still sounding great.

Tony Prior · From: Charlotte NC

Tony Prior · From: Charlotte NC

Do keep in mind that the newer series Fender amps , not BF or SF, use different trannys and the ext. speaker jack , if they have one, is wired from the lead off the Output Transformers to change the overall output load when the ext speaker is plugged in.

Case in point, when the first series of Tweed Blues Deluxe amps hit the market, maybe mid 90's, they did not have an ext speaker jack. The next generation maybe a year or so later did. The good news is ( was) the first series uses the same OT (with all the taps) which meant that the ext speaker jack could be added and wired appropriately, which of course I did with mine. Why Fender didn't do it from the get go- who the heck knows. Apparently they wanted to save $1 for the cost of the chassis mounted switch craft jack. Greater minds than me suggest that they when the chassis were being drilled by CAD, they overlooked the hole for the ext speaker jack ! Which makes total sense. Shocked

_________________
Emmons L-II , Fender Telecasters, B-Benders , Eastman Mandolin ,
Pro Tools 12 on WIN 7 !
jobless- but not homeless- now retired 9 years

CURRENT MUSIC TRACKS AT > https://tprior2241.wixsite.com/website

Stephen Cowell · From: Round Rock, Texas, USA

Dave Mudgett · From: Central Pennsylvania and Gallatin, Tennessee

David Farrell · From: San Diego, California, USA

Hi friends,

Can anyone tell me the weight of their Twin Reverb Combo with a 15" speaker (instead of 2x12) please?

Thanks, Dave
_________________
Dave

Fender pedal steels, amps & guitars. '73 Sho~Bud PRO 1 CUSTOM. Emmons ReSound'65 S-10 4x5.

Dave Hopping · From: Aurora, Colorado

I have the'65 Twin Custom 15. Essentially a Twin Reverb reissue with an Eminence 15' that's supposed to replicate a JBL (I think a D130). The cab is an inch or so taller than standard and the specs say it weighs 64 pounds.

Did a little rummaging around in the Fender Amp Field Guide. They say that a Vibrosonic Reverb -- basically a silverface Twin Reverb with a JBL 15" -- weighs 85 pounds and that the Custom Vibrasonic -- a Twin with some tweaks, a taller cab, and a 15" -- tips the scale at 69 pounds.

My Custom 15 sounds marvelous, but at more than twice the weight of my Milkman Half & Half (with a 15") it stays home and the Milkman goes to work. Winking

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