Goes without saying dude, only worthy goal in life.
The general rule for these kinds of things is if you don't know 100% what you are doing go ahead and poke around in an amp anyways, because it is highly likely you will get a serious shock and then you can sue the manufacturer for inadequate warning stickers.
im looking at the Ultra Plus Schematic and the resistor im pointing out is called "R89" and it sits in between 2 banks of huge capacitors, if that helps any
I added a choke to a 6505 and it removes a bit of the power sag so it'll speed up the attack a little. I found it to be a subtle mod though, good but subtle. If I had to guess, I'd say that you'd need to be replacing the large blue power resistor underneath the filter caps, however I have no electronics qualifications so that would be a guess though, don't go putting a choke in there without being 200% sure, and there's also the old saying of don't go messing with tube amps unless you know exactly what you're doing, because they store massive charges in those capacitors even when turned off, and even if you're just replacing a resistor, the capacitors will still be connected to the resistors, you need to research discharging them before even thinking of working on any amp.
The resistor you are looking for should be inline with the high voltage supply usually after the standby switch and ht fuse. Without a schematic I can't really say though.
Also, whoever said turning an amp off without putting it on standby completely discharges the caps is a fucking idiot who is lucky they haven't killed themselves yet poking around the inside of amps.
well i cant read schematics that well, but it says on the PCB layout that there are 2 R100's, 1 in the power PCB and 1 in the preamp PCB in the standup capacitor bank..
if it was just R89 then i could have done it, but if its R100 i dont have the skills to do that.
well i cant read schematics that well, but it says on the PCB layout that there are 2 R100's, 1 in the power PCB and 1 in the preamp PCB in the standup capacitor bank..
if it was just R89 then i could have done it, but if its R100 i dont have the skills to do that.
If you're having issues with reading schematics and aren't very skilled at this, I'd highly recommend building your chops on some low voltage stuff like pedals first to get the hang of it. There are huge voltages inside these amps and there is a risk if the work is done incorrectly. Plus as for sound, there are mods that will alter the tone and gain more than installing a choke. Preamp tweaks, eq tweaks, hell even just changing the preamp tubes to a different type can make a huge difference.
I'm not saying don't get into modding but given the lack of confidence you're conveying I think it would be a more pertinent idea to do something less dangerous then make your way to hi voltage amp work.
If you have to practice soldering, you're not ready for the inside of an amp yet. As for eq, I was more so referring to modifying the tone stack inside the amp or the gain structure with a few resistor and assorted changes.
If you try it, you run the risk of killing yourself. If you die trying to do this, don't come running to us, we'll just say "I told you so".
FWIW, I have built dozens of pedals, can solder fairly well, can read a schematic, and I still wouldn't try this mod.
Don't do it.
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