This happened to me right after I bought my '67 Deluxe Reverb... got it home played it for about 20 minutes, heard the volume drop dramatically, smelled smoke and shut it off. Same exact screen resistor had blown. In my case it was a bad tube. The shop I bought it from was very cool and not only repaired the amp, but put in a NOS set of JAN Phillips tubes and it has been singing along ever since!
Incredibly useful video for newbies. I wish I had viewed something as instructive as this years ago. The possible causes, the method... Aand as a bonus, there's that Southern gentleman voice.
Thanks to you ( mostly ) and a couple other amp techs on TH-cam, I'm starting to see several types of issues over and over again so at least I know where to start troubleshooting with specific symptoms. I'm a little OCD so I also appreciate all your attention to details and how you install your fixes so mindfully and carefully. You're the real deal. Thanks for all the instruction ( and entertainment ). Blessings to you and glad you got past the poison ivy. I've had one bout with it this past spring - takes about 6 weeks to 2 months to heal. No fun....
I liked the amp forensics portion theorizing on the failure. Analyzing burn patterns and what not. "The resistor failed on this side" was like revealing it couldn't have been suicide because the victim was left handed. Very Columbo. On that theme, so there are no McGyver-esque ways to repair breaches in insulation like that? Fun video.
Good diagnostic video! In this case, it's probably fortunate that the screen grid resistor did not have a good mechanical connection to the tube socket and was able to "unsolder itself", before it went up in flames.
I'd love to see your current limited supply setup and how you built it (if you built it). I had a quick look at your videos and didn't see anything - my apologies if you've done this already.
The shunt on the speaker output jack is not an "infinite load", it's a short circuit to ground. But you already knew that of course...... And if you want to hear examples of me mispeaking you can watch a few of the videos I posted about soldering equipment recently, which are completely live, unscripted, unrehearsed, unedited, and I definitely misspeak! I find talking to myself to be a little bit weird. My wife says she doesn't think it's weird to be talking to herself because she lives with me and I don't listen half the time!
10:00 "𝙄 𝙬𝙞𝙨𝙝 𝙄 𝙝𝙖𝙙 𝙖 𝙧𝙚𝙖𝙡 𝙜𝙤𝙤𝙙 𝙩𝙪𝙗𝙚 𝙩𝙚𝙨𝙩𝙚𝙧" "Real good" is the operative phrase here. There are still plenty of drug store "emissions" tube testers to be had. But they aren't even worth the space they take up in your workshop, even if you get one for free. A transconductance tester aka dynamic conductance tester aka dynamic mutual conductance tester, is worth its weight in gold, if it's still in good working order. Unfortunately, most of the folks who have them for sale know this. But if you're lucky, you might find one at an estate sale where grandpa was an amateur radio operator. Or maybe at a ham fest, but I reckon one might cost a bit more that way. An acquaintance of mine bought a Hickok 750 from an estate sale for a hundred bucks about ten years ago. Money well spent.
Re the continuity bleep at 1.4 ohms... most multimeters will bleep up to a certain resistance threshold which I guess would vary from meter to meter. My old Fluke 25 will give a continuity bleep up to 150 ohms. Above that, I have to switch to measure resistance.
In my experience, most meters have a continuity-test "beep" up to 100 ohms and some like your Fluke cut off the beeper at 150. I've never seen a meter with a continuity test that works above 200 ohms. (It just occurred to me how cute it would be if a meter could be designed to go "beep-beep" like the Roadrunner!).
@@PsionicAudio Their stuff can be short-lived, for sure. They don't appear to offer my Cen-Tech IR (model unk) anymore, but it's been a trooper since 2012 with some pretty heavy use on everything from motorcycle exhaust header pipes, to taking hand/finger temp to determine extent of thoracic outlet syndrome, to measuring heat loss from water pipes, to checking car A/C issues - one of my favorite and most-used devices. If my Cen-Tech died, I'd get a better one for the utility. Separately, great diagnostic vid - very much like that style/approach, with clear ID of test points, explanations of apparent inconsistencies, etc. Most techs probably know that stuff already, but us lay-folk appreciate the detail.
It sounds to me as if Memphis needs to upgrade their electrical distribution a little bit. I'm in woodsy Southern New England and my wall voltage hasn't fallen below a 120V even though it's been in upper 80s and 90-something every day for a month and half and our central air conditioner, and everyone else's AC, has been running continually for weeks. (Our electric bill jumped from a typical $130 a month to $380).
@@PsionicAudio , I am lucky because my house, and one other house that shares the same long extended driveway going up Into the woods, are both powered from a 13KV spur-line, and we each have our own step-down transformer just for our homes. We do, however, typically lose power 3 or 4 times a year for 24 hours or longer due to snowstorms or tropical storms and so I have a portable generator that I can patch in to keep the fridge, well pump, lights and TV, heat and hot water going. I can't run the electric stove or electric clothes dryer off of it, but we've managed just fine for a few days with a propane camping stove. We were without power from Superstorm Sandy for 5 days; the following year we had an October-Surprise snowstorm while the trees still had most of their leaves on, and there was so much tree damage in the region that it knocked our power out for 6 days. Fortunately, extended outages like that are very uncommon for us.
You had us all seating on the edge of our seats, watching a resistor. Nicely done.🙄
This happened to me right after I bought my '67 Deluxe Reverb... got it home played it for about 20 minutes, heard the volume drop dramatically, smelled smoke and shut it off. Same exact screen resistor had blown. In my case it was a bad tube. The shop I bought it from was very cool and not only repaired the amp, but put in a NOS set of JAN Phillips tubes and it has been singing along ever since!
Good store! Stick with 'em, Wes!
@@BradsGuitarGarage Yeah they are legit for sure! big props for Imperial Vintage Guitars in Burbank, CA
Never thought I'd ever watch a resistor with such anticipation, damn you Caldwell, DAMN YOU!!!
THE SUSPENSE!!!!!
This was "Must See TV."
That was well worth watching, a really clear and informative diagnosis. Thanks for posting.
EXCELLENT TEACHING !!! VERY USEFUL
Incredibly useful video for newbies. I wish I had viewed something as instructive as this years ago. The possible causes, the method... Aand as a bonus, there's that Southern gentleman voice.
I made myself slow down and Fred Rogers it.
Thanks to you ( mostly ) and a couple other amp techs on TH-cam, I'm starting to see several types of issues over and over again so at least I know where to start troubleshooting with specific symptoms. I'm a little OCD so I also appreciate all your attention to details and how you install your fixes so mindfully and carefully.
You're the real deal. Thanks for all the instruction ( and entertainment ). Blessings to you and glad you got past the poison ivy. I've had one bout with it this past spring - takes about 6 weeks to 2 months to heal. No fun....
Right ON !!!😉👍
Excellent examination doc.😎
'nothing dramatic is immediately happening ...' Love it!
Very helpful type of video.
I admire your customer relation attitude.
I liked the amp forensics portion theorizing on the failure. Analyzing burn patterns and what not. "The resistor failed on this side" was like revealing it couldn't have been suicide because the victim was left handed. Very Columbo. On that theme, so there are no McGyver-esque ways to repair breaches in insulation like that? Fun video.
Thanks. I could have slipped a little heat shrink over that damaged section of heater wire. But it wasn’t necessary once the wire was moved away.
@@PsionicAudio Fair enough, def trust that it would be fine repair as is. Mostly romanticizing esoteric amp repair knowledge... plus TV references.
Excellent step-by-step methodology of amp troubleshooting. Now there's a Bobby Dazzler!
Thanks for a very informative video!
Great video and amplifier diagnostics. 👍
Good diagnostic video! In this case, it's probably fortunate that the screen grid resistor did not have a good mechanical connection to the tube socket and was able to "unsolder itself", before it went up in flames.
Another master class video. I wanted to see that resistor burn in real time! 🔥🎆
Thank you Mr Caldwell! I always learn something from your videos!
Great troubleshooting info, Lyle! Thank you.
Solid info. Thank You Lyle.
Excellent instructional trouble shooting video. Even a little dramatic watching to see if that resistor smoked…
Thanks for the video Lyle!
I learned how to do things from this! Thank you!
Mahalo Lyle! Great tips.
I'd love to see your current limited supply setup and how you built it (if you built it). I had a quick look at your videos and didn't see anything - my apologies if you've done this already.
Wish I lived in Memphis!
🎶 Back to the basics of love🎶
The shunt on the speaker output jack is not an "infinite load", it's a short circuit to ground. But you already knew that of course...... And if you want to hear examples of me mispeaking you can watch a few of the videos I posted about soldering equipment recently, which are completely live, unscripted, unrehearsed, unedited, and I definitely misspeak! I find talking to myself to be a little bit weird. My wife says she doesn't think it's weird to be talking to herself because she lives with me and I don't listen half the time!
I meant it’s the opposite of “no load”
Thanks for posting this Lyle. Would there be any value in using a fusible plate resistor?
Not really.
10:00 "𝙄 𝙬𝙞𝙨𝙝 𝙄 𝙝𝙖𝙙 𝙖 𝙧𝙚𝙖𝙡 𝙜𝙤𝙤𝙙 𝙩𝙪𝙗𝙚 𝙩𝙚𝙨𝙩𝙚𝙧"
"Real good" is the operative phrase here. There are still plenty of drug store "emissions" tube testers to be had. But they aren't even worth the space they take up in your workshop, even if you get one for free. A transconductance tester aka dynamic conductance tester aka dynamic mutual conductance tester, is worth its weight in gold, if it's still in good working order. Unfortunately, most of the folks who have them for sale know this. But if you're lucky, you might find one at an estate sale where grandpa was an amateur radio operator. Or maybe at a ham fest, but I reckon one might cost a bit more that way. An acquaintance of mine bought a Hickok 750 from an estate sale for a hundred bucks about ten years ago. Money well spent.
I think we should start a go fund me page for you and by the 2 maximatchers or something!
You’ve plugged into the extension jack! 😂
???
The MV is in the aux jack hole.
Re the continuity bleep at 1.4 ohms... most multimeters will bleep up to a certain resistance threshold which I guess would vary from meter to meter. My old Fluke 25 will give a continuity bleep up to 150 ohms. Above that, I have to switch to measure resistance.
I rarely use continuity mode as a result. I thought it might be good in the video, but it’s so inaccurate.
In my experience, most meters have a continuity-test "beep" up to 100 ohms and some like your Fluke cut off the beeper at 150. I've never seen a meter with a continuity test that works above 200 ohms. (It just occurred to me how cute it would be if a meter could be designed to go "beep-beep" like the Roadrunner!).
...and the tweed princeton
Oh Yeah ....cheers
You are really amazing
Infrared thermometer on that resistor would be a way to see if it's heating up. Cheap ones at harbor freight.
Harbor Freight stuff breaks in my experience. No more.
@@PsionicAudio Their stuff can be short-lived, for sure. They don't appear to offer my Cen-Tech IR (model unk) anymore, but it's been a trooper since 2012 with some pretty heavy use on everything from motorcycle exhaust header pipes, to taking hand/finger temp to determine extent of thoracic outlet syndrome, to measuring heat loss from water pipes, to checking car A/C issues - one of my favorite and most-used devices. If my Cen-Tech died, I'd get a better one for the utility.
Separately, great diagnostic vid - very much like that style/approach, with clear ID of test points, explanations of apparent inconsistencies, etc. Most techs probably know that stuff already, but us lay-folk appreciate the detail.
Weber,,,,,, yep
It sounds to me as if Memphis needs to upgrade their electrical distribution a little bit. I'm in woodsy Southern New England and my wall voltage hasn't fallen below a 120V even though it's been in upper 80s and 90-something every day for a month and half and our central air conditioner, and everyone else's AC, has been running continually for weeks. (Our electric bill jumped from a typical $130 a month to $380).
I’m in an old part of the city. We see between 108-127 this time of the year. It’s fun.
@@PsionicAudio , I am lucky because my house, and one other house that shares the same long extended driveway going up Into the woods, are both powered from a 13KV spur-line, and we each have our own step-down transformer just for our homes. We do, however, typically lose power 3 or 4 times a year for 24 hours or longer due to snowstorms or tropical storms and so I have a portable generator that I can patch in to keep the fridge, well pump, lights and TV, heat and hot water going. I can't run the electric stove or electric clothes dryer off of it, but we've managed just fine for a few days with a propane camping stove. We were without power from Superstorm Sandy for 5 days; the following year we had an October-Surprise snowstorm while the trees still had most of their leaves on, and there was so much tree damage in the region that it knocked our power out for 6 days. Fortunately, extended outages like that are very uncommon for us.
@@PsionicAudio Wow, that's a wide range!
@@PsionicAudio I've seen between 218-249 on some days here recently in Melbourne, Australia. Not that it's a competition, just a pain in the bum
Without a screen resistor the tube will not conduct.