Joey Voltage

Fixed a few of 'em, maybe not that exact model, but similar high wattage fender UL models from that era, as well as many other 70's fender models that have worse problems, and laughable/frustrating lead dress. although I don't keep count of what I do, I will be sure to from now on incase you ask. How about you?,

and if you don't need a lesson on screens, what does the 470r value mean to you? enlighten me, If you know something I don't about this particular model, or you feel I'm overlooking something, Do teach me, I'm fully willing to hear you out and learn about what you have to say, (and don't go AIM'ing somebody else, or Jon like you did last time this happened, I have no interest in going at it with you, rather than making this productive) I'm completely willing to hear you out. this is a discussion, not a pissing match. If you have some knowledge share it.

Not at all, no, we are in agreement. and like I said too, your amp can oscillate with things you are not even aware of such as the amount of -fb that is used, if you don't consider all the phase shifts you have with in the loop, and what your limit for feedback is if you don't mind them. most commercial amps don't mind this and probably the majority of them do ring or oscillate ultrasonically!, but the screen stopper wont fix this. I'm also aware that some UL amps can oscillate too if no screen resistor is used, but neither of us are advocating not using one, and it really takes a very small value such as 47r-100r to stop it if it does occur. the reason why I brought up the grid stopper was because It seemed like you convoluted two different things, or your being a bit too cryptic... but if you weren't im fully willing to listen.

Now if you are hinting at OT failure due to oscillations railing up the core dissipation of the OT, screen resistors aren't going to help that unless they are directly causing the oscillation, there are other ways to dampen that which will cause the OT to over dissipate, and the oscillation scenario wont cause the flyback spikes that will take out the screens in the fuse sense. But If I'm missing your point, tell me, and what you are hinting at.... maybe you are getting at something I'm not considering, or thinking about... happens to all of us, and I'm happy to learn whatyou have to teach

for transient spikes, you are much better off using flyback diodes. than relying on those screen resistors, and like I said, not all resistors types will pop open by design, and underrating them will also have a consequence.

Oscillation in the power supply is almost always in the form of of positive feedback at low frequencies, which will produce that motorboating sound, high frequency oscilation is unlikely in the power supply. That kind of oscliation wont cause damage to the OT as far as I'm aware. justsounds like crap

and I was talking about the designer/engineers at ATT/Western Electric who licensed some of these circuits to fender in the first place. probably not that particular one