65 Fender Twin Reverb (re-ssue)

tja · Newbie Alert Joined: 13 May 2008 Posts: 2

I need some help here...

...at our church we have a 65 Twin Reverb (re-issue)...I think re-issue...

...we want to remove some tubes so that we can crank the thing up! As is, I can only put it on "3" or I am killing someone! So...the thought is remove one or more tubes...perhaps allowing to crank it up to 5...7 and let the remaining tubes really...be proud of themselves.

Not sure if this is possible...I downloaded the schematics and will have a look...

any help is appreciated...

tja Question

owwdatune · Posted: Tue May 13, 2008 10:36 am Post subject:

this is your "safe" answer ---> http://www.tedweber.com/atten.htm
_________________
~T~...Live a little >crank it up< ...

--> SAVE A LIFE - ADOPT A SHELTER/RESCUE PET <--

Herb · Posted: Tue May 13, 2008 4:44 pm Post subject:

~T~ is right, get an attenuator. You can remove the power tubes in pairs (you have to do either the center two or the outer two, otherwise you disable the entire amp.) but you only disable one channel, and you don't lose much if any volume. I also don't think it's good for the transformer because it continues to try to push the tubes that aren't there. If you remove pre-amp tubes, the amp will only cease to function in whatever area the tube is assigned (amp, reverb, tremelo...). You can also get the desired result by using overdrive or compressor pedals. That's probably the cheapest solution.
_________________
Yer guitar pickin' friend,
Herb
"It don't mean a thing if it ain't got that swing!"
Doghouse Jazz

tw001_tw · Puppy Joined: 26 Mar 2007 Posts: 204 Location: St. Louis

The above 2 are correct.

Its true, you can pull tubes (out in pairs as Herb said). But it is not an ideal
thing to do and for the reason of volume, it most likely will not work out
well. Reducing wattage in 1/2 equates to I think the number is -3dB change
which is not too detectable.

It also increases the B+ (high voltage) in the amp a bit which is normally
not a big deal, unless 'something' gets close to its limit at 'normal' voltage.

It also changes the output impedance. So without altering the speakers or
the impedance, the OT & load will be mismatched.

In a nut shell, if precaution is taken, and the result is what you want, it is
doable.. It just doesn't sound like it will provide the result you are looking for.

tja · Newbie Alert Joined: 13 May 2008 Posts: 2

...well...if I will only drop -3db, that is useless...and even more alarming is the thought of overloading circuitry...outside of design that is Wink

...I will look into the antenuator idea...is it the same concept of the Power Soak???

russ@savage · Posted: Wed May 14, 2008 3:37 pm Post subject:

The best reply so far is the pedal idea. Attenuators/power soaks are fine, but they will shorten your tube life. Also, with a Twin, especially the reissue, they were not meant to break up. They are clean and when the do distort, it's not really of the pleasant type. There are a million and two pedals out there, find one you like, and save your tubes. Or, find a low powered amp that will give you what you want.