pulling two tubes on a Fender Twin Reissue

[hector]

I have a Fender Twin '65 Reissue. I hear of people pulling out two power tubes (the two inner OR the two outer) to reduce power on older Twins. Is it safe to do this on a '65 Reissue circuit board version of the Twin? I don't really want to reduce power. I'm thinking, in a pinch, if I damage a tube (or two) travelling to a gig, I can still play the show. Thoughts?

 

[Dana Olsen]

The principal reason for removing a pair of power tubes is to coax some output stage gain at a lower volume on a non master vol amp. A Twin is designed to have very high headroom and little output tube distortion.

I'd say you're barking up the wrong tree here by pulling two power tubes. If you need the amp to be quieter, turn it down. If you need gain sounds, you're gonna have to use a pedal anyway if you're playing through a Twin.

Whether it's safe or not, I don't think it'll get you what you want out of the amp by pulling two power tubes. I think it's OK to do (I'm not a tech, but I've done it on older Twins) - on a class A/B amp like a Twin you'd pull the middle pair OR the outside pair. It'll just sound like a Twin, but when you really crank it, it'll be a little quieter than it was at full power. There may be other issues that go with removing tubes .....

Not worth it, IMHO, in a Twin.

Dana O.

 

[tfunster]

I think the impedance changes as well when you pull tubes, but don't quote me on that.

 

[stevel]

Check out this thread where I got answers to this question:

https://www.thegearpage.net/board/index.php?threads/500048

Best,
Steve

 

[Eric Dahlberg]

I'm thinking, in a pinch, if I damage a tube (or two) travelling to a gig, I can still play the show.

Yes, in a pinch, you absolutely can pull either the inner or outer pair of tubes. Some people even suggest this as standard practice, though I personally don't since you're then running your transformer incorrectly.

 

[hector]

O.K. So, "in a pinch", like if I would damage a tube going to a gig, I can pull two power tubes and maybe one speaker connection to get 8 ohms (normally 4 ohms, parallel). Some of you don't understand what I'm asking. I don't intend to do this on purpose to change the tone. Just looking at ways to avoid carrying extra amps, tubes, etc. when travelling to a gig. A "band-aid".

 

[Austinrocks]

the channel 2 input is an attenuator 6db or my Vibroalux Custom and hot rods had it as well, really necessary on the hot rods with the stupid volumes, it you plug in both channels on my Vibralux Custom it was bypassed, which I used a lot for keyboards.

http://www.fender.com/support/manuals/pdfs/manuals_elec/guitarpdf/65_Twin_Custom_15.pdf