The stronger signal will push the second gain stage (V4 tube) harder and give you increased sustain, compression and harmomics.
This mod does not change the amp’s clean headroom but increases the preamp gain and preamp distortion.
This mod does not alter the tone significantly when amp is played clean or when only the power amp section distorts.
You’ll have to increase the volume setting to achieve a similar volume as before.
Sadly, we are seldom offered the opportunity to turn the volume above 3 on a Twin Reverb.
Instead we have played many nights with a thin and unpleasant tone, even worse with a sparkling, clean sounding strat.
It is designed not break up like the other Fender amps.
You need to have your expectations set correctly to be able to appreciate the evil Twin. The big transformers and speakers makes this amp weigh around 40kgs, a burden too big for many gigging players who cannot (yet) afford a crew of roadies. If you want tube amp breakup and smoking tones with no pedals you will experience many fights with your band mates and club owners.
It is so easy to enable and disable that it can hardly be called a mod.These tubes have different frequency responses than 12AX7, particurlarly when distorting.People describe these tubes to have less harsh and buzzy distortion.If you pull one tube the other channel’s tube will be hotter biased and offers more gain.
The amp will play louder than before given the same volume knob setting.You should/can also disconnect one of the speakers to not have an impedance mismatch.