I recently discovered your channel. I used to manufacture whole guitars in a small shop and then manufactured electric guitar and bass necks and bodies and I finally moved on to guitar repair in a legitimate shop after doing it on my own for many years, which I find a lot more challenging than manufacturing because I have to know so much more about all the various types of instruments and all the issues that can appear, as opposed to manufacturing where I only had to know about 5000 different things, now I have to know about 50,000 different things. Anyway! After that ridiculously run on sentence (followed by another one) I just wanted to say how much I appreciate your channel. I don't know why you are not getting more likes and follows, maybe it's your sanguine ways or your not so sardonic presence, which so many repair videos have. I personally like your vibe a lot and you are sharing a lot of valuable information and I can tell that you're doing it out of love. I really got a lot out of the 60s Rickenbacker refret series with all that finishing on the board. We have that exact same problem on our bench right now and your videos helped a lot!
So you’re an amp tech that is uncomfortable using your DMM in ammeter mode because you might forget to put it back into voltmeter mode? And you ‘think’ it’s called crossover distortion?
Help! my Deluxe Reverb Reissue has a loud humming sound. It´s like a 60 cycle hum from hell. There is no sound variance either the guitar is connected or not. Changed all the tubes for new ones for no avail. I looked inside the hood and the chassis is perfect, there is no burning, leakage. Inside the dog house the capacitors ar OK, all of them. When I measured the bias on the valves ( last time i did that i set them at 25 mA about a year ago) you cannot go more than 5 mA, and the close you bias towards 5 mA the louder the hum gets. Any hint as what is happening!
Hi Dante. Always difficult to diagnose without seeing it in person, but my gut tells me it's the power supply caps. That 5mA you mention - remember that when the valves are at 0mA, they're off altogether. 5mA is just trickling on, and they're just beginning to amplify. And it sounds like the problem is pretty close to the power valves. A few years ago I worked on a Hot Rod (or something like it) and the reservoir caps (the first ones after the rectifiers) were dead. Symptoms sound the same as your amp's. There were no physical signs of deterioration, they just… died inside I guess. If it's not the caps, and both power valves are conducting, then it might be a problem with the output transformer. Maybe one of the windings in the primary legs have fused. You see, normally the power getting to the valves is a kind of sawtooth wave, which would sound unpleasant, but in a push-pull amplifier, the valves and the output transformer work to cancel out that hum. If there's a problem with one side of that push-pull system, there's no hum cancellation, and so you get… hum. All in all, I'd say your amp definitely needs a trip to hospital. Good luck with it. Hopefully it's just the caps, as these are cheaper to replace than an output transformer.
@@RNRWorkshop Hey Leif !!!!, thanks for taking the time to reply. I guess it´s time to send this bad boy to the hospital, I´m not qualified on messing with high voltage caps. Hopefully it´s not the output transformer. Anyway, really appreciate your help, happy holidays. Congrats on your RNR Workshop channel. Cheers from Mexico. Dante
If your tubes go bad enough, you could get a plate-heater short, which causes a spike in current, and something is going to go - HT or flament fuse, or a little PCB fuse after the rectifier. Or worse, one of the transformers. I recently had to replace a power transformer in an old WEM amp. The valves went bad, thus pulling too much current and… someone had installed a 2-amp fuse where there should have been a 1-amp. Instead of the fuse sacrificing itself, that spike in current took out the HT winding of the power transformer. So, valves going bad isn't always the end of the story. But… If you're replacing valves before anything goes wrong, chances are you'll be fine. But… not all valves conduct at the same rate, hence the adjustable bias voltage. In an extreme case, they could be pulling too much current, thus shortening their life or stressing either of the transformers. Too little current, and the power amp will lack response. Again, in an extreme example, too little current will keep the plate voltage high, beyond the 6V6s' theorhetical maximum. Like I said, chances are you'll be fine, but these are the things we nerds consider when handling other people's gear.
@@jdl2180 If science has taught me anything, it's that observation beats speculation. I have no idea what you'd be putting in there, or how much current they'll draw, etc.
My most profound apologies that you wasted your precious time watching this garbage, your majesty. And to think you wasted even more time leaving a comment.
![Repairing a VINTAGE Silverface Fender Princeton Reverb [Full Service+DEMO]](/img/n.gif)
"I like Turtles..." and Solid State Amps since I myself know "Murphy's Law".
I recently discovered your channel. I used to manufacture whole guitars in a small shop and then manufactured electric guitar and bass necks and bodies and I finally moved on to guitar repair in a legitimate shop after doing it on my own for many years, which I find a lot more challenging than manufacturing because I have to know so much more about all the various types of instruments and all the issues that can appear, as opposed to manufacturing where I only had to know about 5000 different things, now I have to know about 50,000 different things. Anyway! After that ridiculously run on sentence (followed by another one) I just wanted to say how much I appreciate your channel. I don't know why you are not getting more likes and follows, maybe it's your sanguine ways or your not so sardonic presence, which so many repair videos have. I personally like your vibe a lot and you are sharing a lot of valuable information and I can tell that you're doing it out of love. I really got a lot out of the 60s Rickenbacker refret series with all that finishing on the board. We have that exact same problem on our bench right now and your videos helped a lot!
You are way too kind! Makes my day to know that SOMEONE out there gets something out of my insanity. Good luck with the Ric. They’re a strange beast.
Thanks, man. Helpful and enjoyable. Much appreciated 🤙
Great work
Thanks so much for your knowledge! Amazing! You’re a classic cat too…! LOL
So you’re an amp tech that is uncomfortable using your DMM in ammeter mode because you might forget to put it back into voltmeter mode? And you ‘think’ it’s called crossover distortion?
You forgot to mention you also need to pay rent and eat
Help! my Deluxe Reverb Reissue has a loud humming sound. It´s like a 60 cycle hum from hell. There is no sound variance either the guitar is connected or not. Changed all the tubes for new ones for no avail. I looked inside the hood and the chassis is perfect, there is no burning, leakage. Inside the dog house the capacitors ar OK, all of them. When I measured the bias on the valves ( last time i did that i set them at 25 mA about a year ago) you cannot go more than 5 mA, and the close you bias towards 5 mA the louder the hum gets. Any hint as what is happening!
Hi Dante. Always difficult to diagnose without seeing it in person, but my gut tells me it's the power supply caps. That 5mA you mention - remember that when the valves are at 0mA, they're off altogether. 5mA is just trickling on, and they're just beginning to amplify. And it sounds like the problem is pretty close to the power valves. A few years ago I worked on a Hot Rod (or something like it) and the reservoir caps (the first ones after the rectifiers) were dead. Symptoms sound the same as your amp's. There were no physical signs of deterioration, they just… died inside I guess.
If it's not the caps, and both power valves are conducting, then it might be a problem with the output transformer. Maybe one of the windings in the primary legs have fused. You see, normally the power getting to the valves is a kind of sawtooth wave, which would sound unpleasant, but in a push-pull amplifier, the valves and the output transformer work to cancel out that hum. If there's a problem with one side of that push-pull system, there's no hum cancellation, and so you get… hum.
All in all, I'd say your amp definitely needs a trip to hospital. Good luck with it. Hopefully it's just the caps, as these are cheaper to replace than an output transformer.
@@RNRWorkshop Hey Leif !!!!, thanks for taking the time to reply. I guess it´s time to send this bad boy to the hospital, I´m not qualified on messing with high voltage caps. Hopefully it´s not the output transformer. Anyway, really appreciate your help, happy holidays. Congrats on your RNR Workshop channel. Cheers from Mexico. Dante
@@dantealtieri7252 Cheers, have a good one. Hope it's a simple fix.
I have the 65 reisue. If my tubes go bad I will just stick some new ones in and see how it sounds. How different can they be?
If your tubes go bad enough, you could get a plate-heater short, which causes a spike in current, and something is going to go - HT or flament fuse, or a little PCB fuse after the rectifier. Or worse, one of the transformers. I recently had to replace a power transformer in an old WEM amp. The valves went bad, thus pulling too much current and… someone had installed a 2-amp fuse where there should have been a 1-amp. Instead of the fuse sacrificing itself, that spike in current took out the HT winding of the power transformer. So, valves going bad isn't always the end of the story.
But… If you're replacing valves before anything goes wrong, chances are you'll be fine.
But… not all valves conduct at the same rate, hence the adjustable bias voltage. In an extreme case, they could be pulling too much current, thus shortening their life or stressing either of the transformers. Too little current, and the power amp will lack response. Again, in an extreme example, too little current will keep the plate voltage high, beyond the 6V6s' theorhetical maximum.
Like I said, chances are you'll be fine, but these are the things we nerds consider when handling other people's gear.
@@RNRWorkshop ok, thanks for the response. So If I change my tubes before they go bad it should be ok?😊
@@jdl2180 If science has taught me anything, it's that observation beats speculation. I have no idea what you'd be putting in there, or how much current they'll draw, etc.
@@RNRWorkshop Then again, there is "Murphy's Law" to seriously consider.
I learned absolutely nothing from this video…. and let’s leave the comedy to the professionals.
My most profound apologies that you wasted your precious time watching this garbage, your majesty. And to think you wasted even more time leaving a comment.