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Topic: Fender Twin Reverb, 135 watts with 4x6L6s....Possible? |
ajm
From:
Los Angeles
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Posted 1 Sep 2019 9:05 am |
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Unless I have my information wrong..........
I saw a Twin Reverb with 4 x 6L6 power tubes.
The chassis was marked 135 watts.
Is 135 watts even possible with these power tubes?
That would be just shy of 35 watts per tube.
Has anyone ever measured one and if so, what did you find? |
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Jack Hanson
From:
San Luis Valley, USA
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Posted 1 Sep 2019 9:45 am
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I'm certainly no techie, and admittedly wouldn't know a "watt" from a "what." But the Fender Amp Field Guide lists the Silverface Twin Reverbs from 1977 to 1982 as 135 watts. Where their information originated is anyone's guess, but likely comes from figures published by Columbia. And we all know how their stewardship of the Fender brand played out.
http://www.thevintagesound.com/ffg/ |
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Brian Hollands
From:
Geneva, FL USA
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Posted 1 Sep 2019 9:49 am
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The 135 watt Twins are the later "Ultralinear" output transformer models. Supposedly clean as possible all the way up the dial
_________________
'81 Sho-bud LDG, 2 EMCI's |
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Jim Cooley
From:
The 'Ville, Texas, USA
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Posted 1 Sep 2019 10:02 am
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| I believe Dicky Overbey played his LDG through an Ultralinear Twin with an orange frame 15" JBL. |
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Larry Dering
From:
Missouri, USA
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Posted 1 Sep 2019 12:57 pm
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| I have a ultralinear Twin Reverb that's marked 135 watts. It has 2 JBL D120f speakers. Loud and clean all way up. My other Twin Reverb from 74 is marked 85 watts. Both have master volume controls. |
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Bobby Nelson
From:
North Carolina, USA
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Posted 2 Sep 2019 1:01 am
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| My 73 Twin is marked 100 watts. The 135 watt ultralinear may have something to do with the transformer, I'm told. |
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Michael Brebes
From:
Northridge CA
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Posted 2 Sep 2019 6:10 am
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With the ultralinear power amp design it is indeed possible of coaxing that much wattage out of four 6L6 tubes. Most guitar players don't like the sound of them because it brings down the amount of natural distortion that is in the power amp section.
_________________
Michael Brebes
Instrument/amp/ pickup repair
MSA D10 Classic/Rickenbacher B6/
Dickerson MOTS/Dobro D32 Hawaiian/
Goldtone Paul Beard Reso
Mesa Boogie Studio Pre/Hafler 3000
RP1/MPX100 |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 2 Sep 2019 7:04 am
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I believe the 135 watt ultra-linear Twin was made between 1977 and 1982. The design is based on a hi-fi premise, with extra taps on the output transformer for improved linearity. It's super loud and clean, but the high voltages on the 6L6's (more than they were really ever designed for) really puts a strain on them. It's an arm-stretcher for sure - not quite as bad as the Super~Twin, but heavier than the standard Twin Reverb. Killer steel amp, but carrying it up and down steps gets old.  |
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Tommy Boswell
From:
Virginia, USA
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Posted 2 Sep 2019 7:19 am
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| I have a Bassman 70, ultralinear with 2 6L6s rated at 70 watts. "Ultralinear" makes the difference. |
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Larry Dering
From:
Missouri, USA
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Posted 2 Sep 2019 7:33 am
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| Donny I had one blown JBL so I swapped to Eminence and kept the old speakers. It's a tad lighter but still too much to lift. I have considered a split cab but I have so many lighter SS amps I just use it at home. |
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ajm
From:
Los Angeles
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Posted 2 Sep 2019 9:38 am
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I believe that Donny and a couple of others are thinking what I am.
I haven't looked it up, but from memory I seem to remember a max 6L6 dissipation of 22-25 watts. (That may have been 70%? I don't remember.)
That, and increasing plate voltages, could be like getting too close to the edge at the Grand Canyon.
Correct me if I'm wrong, but wasn't the Super Twin a different animal, with 6 x 6L6s, and not 4? |
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Ken Fox
From:
Nashville GA USA
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Posted 2 Sep 2019 9:53 am Twin
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JJ brand 6L6GC are 30 watts per tube and 5 watts plate dissipation The original 6L6 (not 6L6GC)and 5881 tubes were around 22 watts.
Best power results I ever got with a dummy load, scope and signal generator
100 watt Twin around 80 watts clean
135 watt UL Twin around 100
watts clean
That was at no distortion. I think Fender rated the amps at around 20 or maybe 20% distortion??
Last edited by Ken Fox on 2 Sep 2019 3:19 pm; edited 1 time in total |
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Steve Hinson
From:
Hendersonville Tn USA
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Posted 2 Sep 2019 2:51 pm Tell you what...
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A 135 watt Twin Reverb with good tubes,working exactly like it should,is strong...
A good friend of mine loaned me one and I used it on a couple of sessions...strong...
He had somebody put the chassis in a head cab...still pretty heavy...
It made a believer out of me though...
SH
Last edited by Steve Hinson on 8 Sep 2019 5:10 am; edited 1 time in total |
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Dave Meis
From:
Olympic Peninsula, Washington, USA
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Posted 2 Sep 2019 5:53 pm
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I put my '79 in a Rick Johnson cab with a single neo 15 and got it down to about 65#. The chassis ALONE weighs about 48#.. never seen such a big chunk of iron. But it sounds glorious with pedal steel!  |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 3 Sep 2019 6:59 pm Re: Twin
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| Ken Fox wrote: |
...Best power results I ever got with a dummy load, scope and signal generator
100 watt Twin around 80 watts clean
135 watt UL Twin around 100
watts clean
That was at no distortion. I think Fender rated the amps at around 20 or maybe 20% distortion?? |
Ken, was that an inductive load, or a resistive load? (I believe the inductive load changes power with frequency, whereas the resistive one doesn't.) Also, I seem to remember decades ago that Fender used to rate their amps at 10% distortion, but I'm not sure if they ever changed that figure.
Re: The tube life in the ultra-linear TR. It used to be that re-tubing every year wasn't a big deal, but the tube prices these days can make you think a little about having an amp that requires frequent re-tubing. I had a friend that had an U/L TR, and he had one or two of the 6L6's short out almost every year. |
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Ken Fox
From:
Nashville GA USA
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Posted 4 Sep 2019 6:14 am
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My test rig consists of two 200 watt wire wound resistors. I use a switch to select 4 or 8 ohms with the setup
The plate voltage is more higher on the UL Twin. That is why I recommend JJ tubes as they can handle the higher voltage of around 500 VDC present in these amps
Even higher plate voltages are used in Music-man amps JJ tubes are a great choice for them as well |
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Dave Meis
From:
Olympic Peninsula, Washington, USA
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Posted 4 Sep 2019 10:17 am
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| I've had good luck with the Tung Sol STRs in my UL which, when biased up, is running 505/510 volts on the plate .. the STRs seem to have a little stronger mids than the JJ, but purely subjective, I know. |
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Stephen Cowell
From:
Round Rock, Texas, USA
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Posted 5 Sep 2019 3:17 pm
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The UL amps use the screen dissipation watts in the output, rather than dumping it through a screen resistor.. Takes a special Output transformer.
_________________
Too much junk to list... always getting more. |
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