I just had the transformer replaced in my amp and the tubes are pretty old. I get wierd sounds out of my amp, but only on the gain channel. It sounds like someone installed a rotary phone in in it. Could it be bad preamp/poweramp tubes, or should i take it back to the shop?
@shreddmaster666 - good troubleshooting is not only finding what is bad but determining what is good. Therefore, in an effort to eliminate the possibility of the tubes being an issue, I recommend switching the positions of all the preamp tubes. If the quality of the noise changes (more or less noise or sounds different), then the trouble may be a preamp amp tube. If the noise is exactly the same as before, then the preamp tubes probably aren't the issue.
Does the microphonic sound come from the speakers? Or just the tube itself? I get these weird undertones when playing certain intervals up high on the G, B, and E strings. Kinda sounds like holding a rubber band up to your ear and strumming it. But the sounds seems to come out of the speakers not the tube.
@skull2510 - the actual microphonics are a result of the tube. The microphonic tube is creating its own electrical "noise" that is being amplified and reproduced by the amp and becomes sound from the speaker. It sounds like you may have a microphonic power tube or you may have a bad solder connection.
@TheeAldeen - I imagine there is more than one electronics hobbyist in your town. Electronics is quite fun ... sort of like Legos but with components.
Wow I have N-E-V-E-R NEVER seen a pair of microphonic tubes come from Tube Depot. They have always supplied excellent current production stuff. OK with my test rig every tube ever made is microphonic at some point. It has always required extreme torture to make a Tube Depot pretested tube pick up outside noise. Licking? No, but, I've had sweat drip on a tube and the glass failed with an implosion. The boss is a cheapskate & kept the shop 90 deg+ all summer. His office was <80, but not mine.
@Satchmoeddie - those darn slave driving managers. My shop at home doesn't have adequate AC and I've sweated into a few amps. I'm sure I'll sweat into several more this summer. Keep testing and fixin'
@ManMartin - All tubes are microphonic to varying extents. The goal is to find and use the least microphonic tubes. Thankfully, we screen these tubes prior to shipping out and dispose of the tubes that don't pass inspection. In the video, I had pulled a pair of tubes from a shipment we had just received that hadn't been inspected. It is a great example of the craziness of tube.
@Iseekoutthetruth - Charging a car battery requires being able to supply a source of free electrons (electrical current). And although, I've encountered a few microphonic caps (usually ceramic disc caps), microphonic caps are unable to provide any free electrons.
hey! i have a fender hot rod deluxe and when i play lower notes the amp starts to make a chaking noise. i think that is something in the electric board but im not sure. do you have any clue what this might be? thanks.
@rodrigoconstantino - on these amps, I recommend visually inspecting the tube socket board for broken solder connections. Remove the old solder and install new solder for any broken connections. Additionally, inspect the input jack for broken solder connections and clean the f/x loop jacks.
@Axeman2006 - Tapping on tubes with bare fingers, even while the tube is operating, is not problematic. Tubes are not like high vacuum light bulbs. Finger prints on the glass will not hurt a vacuum tube. Licking is another matter ... don't lick vacuum tubes while they are on. You will get burnt and it will be very uncomfortable explaining how it happened.
@1kaptenqk - the comment I was responding to when I made the "licking" response was commenting on the use of my bare hands tapping on tubes. I mentioned that touching a tube while operating isn't a problem ... licking, well, that would be a different matter. Imagine explaining why one's tongue is burnt ... not a very positive response.
I have been getting this sound that is like "Puff Puff Puff". I disconnected everything and turned it back and I think it "might" have went away. Does that sound like a microphonic power tube?
@andy92811 - could be a microphonic power tube ... could be a microphonic preamp tube as well. If the sound returns, try tapping on each of the tubes individually to see if you can narrow it down to a particular tube.
People can you help. Got a fender hot rod deluxe about a month ago. Just recently i started hearing like a tambarine style rattling, then yesterday at band practice if i turned the drive channl above 6 i just got this feedback nosie just a constant nosise. I unpluged and did the same and it still did it any ideas what that could be nice one
@Dlow2410 - sounds like it may be a bad preamp tube. Try shifting all of the preamp tubes on position to the left and if the tone of the noise changes, then one(or more) of the preamp tubes is bad. Keep in mind, all tubes are microphonic to some degree ... the goal is to find the ones with the least problems to use in your amp. Good luck
@Rexusmetal - The acceptable bias range is between 50% and 70% of the KT88's plate dissipation rating, which is 42W. With a plate voltage of about 470V, the acceptable bias range should be 44mA - 62mA per tube. The lower 50% range will give thicker bass response and wider headroom; the higher range will give more pronounced midrange and quicker dynamics.
I Just replaced the pre and power tubes in my amp and now I'm getting this jangley high frequency rattle kinda sound when playing. It does not sound like a sustained tone and never heard it before with my old tubes. Do you think it's an issue with the pre or power tubes?
@menowshow - sounds like a preamp tube. Try installing your old preamp tubes one at a time and testing the amp in between each tube. When the noise stops, you will have found the issue. It could be a power tube, just follow the video and you should be able to identify the bad tube.
Tubes will forever be notorious for having issues. Solid state equipment has much less issues but the tone isn't the same. As for me, I'm willing to deal with the troubles and have great tone.
Now that I think about it using old microphonic tubes that nobody wants anymore with a microphone as an effect you put in a box, screwed onto the inside of a cabinet with an external on/off switch and a volume treadle would be a kinda cool...
Add some sustaining Fuzz like a Big Muff Pi and some digital massive cave type reverb and it would be a great effect for drone music.
In my other microphonic tube video, I discover a microphonic preamp tube in the middle of playing. Same sort of off-the-cuff excitement, check it out.
I have an earlier video where I discover a microphonic preamp tube right in the middle of playing. I was just playing along and the "drone" of the tube overwhelmed the amp. Check that one out.
I used to have a 50 Cal+ as well. Bought it brand new in 1988. I believe that was my first experience with tube troubles ... it was a bad EL84 at that time. Tubes still have the same troubles but wow they sound good!
Exactly ... it is crazy sounding. Sadly, I've spent hours troubleshooting an amp before only to find that the weird sound was a microphonic power tube. If you come across one of these, I strongly recommend replacing it quickly. Otherwise it may drive you crazy with the silly overtones.
I have a precarious solution for that, but it works. Some ago I reasoned that if the spacer are loose inside they need to be re-tighten. Well how do you do that? Simple: since there is vacuum in the tubes you can torch them. Torch them? Yes sir. You use a small plummer's torch on the spots you see moving inside the tube and the glass will bent towards it because of the vacuum inside.
I am working on this video now. In addition to the video, I also describe how to build a simple and safe shorting probe as well as a little about how to properly form filter caps.
I just had the transformer replaced in my amp and the tubes are pretty old. I get wierd sounds out of my amp, but only on the gain channel. It sounds like someone installed a rotary phone in in it. Could it be bad preamp/poweramp tubes, or should i take it back to the shop?
shreddmaster666 1 month ago
@shreddmaster666 - good troubleshooting is not only finding what is bad but determining what is good. Therefore, in an effort to eliminate the possibility of the tubes being an issue, I recommend switching the positions of all the preamp tubes. If the quality of the noise changes (more or less noise or sounds different), then the trouble may be a preamp amp tube. If the noise is exactly the same as before, then the preamp tubes probably aren't the issue.
TubeDepotTV 1 month ago
Does the microphonic sound come from the speakers? Or just the tube itself? I get these weird undertones when playing certain intervals up high on the G, B, and E strings. Kinda sounds like holding a rubber band up to your ear and strumming it. But the sounds seems to come out of the speakers not the tube.
skull2510 3 months ago
@skull2510 - the actual microphonics are a result of the tube. The microphonic tube is creating its own electrical "noise" that is being amplified and reproduced by the amp and becomes sound from the speaker. It sounds like you may have a microphonic power tube or you may have a bad solder connection.
TubeDepotTV 3 months ago
Comment removed
skull2510 3 months ago
Dude seems like the Coolest Dude Ever. wish we had people like him in my town
TheeAldeen 7 months ago
@TheeAldeen - I imagine there is more than one electronics hobbyist in your town. Electronics is quite fun ... sort of like Legos but with components.
TubeDepotTV 7 months ago
Wow I have N-E-V-E-R NEVER seen a pair of microphonic tubes come from Tube Depot. They have always supplied excellent current production stuff. OK with my test rig every tube ever made is microphonic at some point. It has always required extreme torture to make a Tube Depot pretested tube pick up outside noise. Licking? No, but, I've had sweat drip on a tube and the glass failed with an implosion. The boss is a cheapskate & kept the shop 90 deg+ all summer. His office was <80, but not mine.
Satchmoeddie 10 months ago
@Satchmoeddie - those darn slave driving managers. My shop at home doesn't have adequate AC and I've sweated into a few amps. I'm sure I'll sweat into several more this summer. Keep testing and fixin'
TubeDepotTV 10 months ago
I hope you will get all the bad tubes for your gear and not send them to the costumers...
ManMartin 1 year ago
@ManMartin - All tubes are microphonic to varying extents. The goal is to find and use the least microphonic tubes. Thankfully, we screen these tubes prior to shipping out and dispose of the tubes that don't pass inspection. In the video, I had pulled a pair of tubes from a shipment we had just received that hadn't been inspected. It is a great example of the craziness of tube.
TubeDepotTV 1 year ago
do you think a micro phonic capacitor could charge a car battery?
Iseekoutthetruth 1 year ago
@Iseekoutthetruth - Charging a car battery requires being able to supply a source of free electrons (electrical current). And although, I've encountered a few microphonic caps (usually ceramic disc caps), microphonic caps are unable to provide any free electrons.
TubeDepotTV 1 year ago
hey! i have a fender hot rod deluxe and when i play lower notes the amp starts to make a chaking noise. i think that is something in the electric board but im not sure. do you have any clue what this might be? thanks.
rodrigoconstantino 1 year ago
@rodrigoconstantino - on these amps, I recommend visually inspecting the tube socket board for broken solder connections. Remove the old solder and install new solder for any broken connections. Additionally, inspect the input jack for broken solder connections and clean the f/x loop jacks.
TubeDepotTV 1 year ago
@TubeDepotTV Thanks.
rodrigoconstantino 1 year ago
Hey while your knocking the tube with your bare hands why not touch a few componenets on the circuit board as well.....YIKES you are dangerous man!
I am glad your not my amp tech :)
Axeman2006 1 year ago
@Axeman2006 - Tapping on tubes with bare fingers, even while the tube is operating, is not problematic. Tubes are not like high vacuum light bulbs. Finger prints on the glass will not hurt a vacuum tube. Licking is another matter ... don't lick vacuum tubes while they are on. You will get burnt and it will be very uncomfortable explaining how it happened.
TubeDepotTV 1 year ago 5
@TubeDepotTV wait, why would i like the power tube of a running amp? what did i miss
1kaptenqk 3 months ago
@1kaptenqk - the comment I was responding to when I made the "licking" response was commenting on the use of my bare hands tapping on tubes. I mentioned that touching a tube while operating isn't a problem ... licking, well, that would be a different matter. Imagine explaining why one's tongue is burnt ... not a very positive response.
TubeDepotTV 3 months ago
I have been getting this sound that is like "Puff Puff Puff". I disconnected everything and turned it back and I think it "might" have went away. Does that sound like a microphonic power tube?
andy92811 1 year ago
@andy92811 - could be a microphonic power tube ... could be a microphonic preamp tube as well. If the sound returns, try tapping on each of the tubes individually to see if you can narrow it down to a particular tube.
TubeDepotTV 1 year ago
Comment removed
andy92811 1 year ago
People can you help. Got a fender hot rod deluxe about a month ago. Just recently i started hearing like a tambarine style rattling, then yesterday at band practice if i turned the drive channl above 6 i just got this feedback nosie just a constant nosise. I unpluged and did the same and it still did it any ideas what that could be nice one
Dlow2410 1 year ago
@Dlow2410 - sounds like it may be a bad preamp tube. Try shifting all of the preamp tubes on position to the left and if the tone of the noise changes, then one(or more) of the preamp tubes is bad. Keep in mind, all tubes are microphonic to some degree ... the goal is to find the ones with the least problems to use in your amp. Good luck
TubeDepotTV 1 year ago
@TubeDepotTV HI, I HAVE A MARSHALL 2203KK WITH KT88 POWER TUBES, BUT I DONT KNOW HOW MUCH CURRENT I PUT FOR THE BIAS ADJUSTMENT YOU CAN HELP ME?
Rexusmetal 1 year ago
@Rexusmetal - The acceptable bias range is between 50% and 70% of the KT88's plate dissipation rating, which is 42W. With a plate voltage of about 470V, the acceptable bias range should be 44mA - 62mA per tube. The lower 50% range will give thicker bass response and wider headroom; the higher range will give more pronounced midrange and quicker dynamics.
TubeDepotTV 1 year ago
I Just replaced the pre and power tubes in my amp and now I'm getting this jangley high frequency rattle kinda sound when playing. It does not sound like a sustained tone and never heard it before with my old tubes. Do you think it's an issue with the pre or power tubes?
menowshow 1 year ago
@menowshow - sounds like a preamp tube. Try installing your old preamp tubes one at a time and testing the amp in between each tube. When the noise stops, you will have found the issue. It could be a power tube, just follow the video and you should be able to identify the bad tube.
TubeDepotTV 1 year ago
that's totally what i was dealing with... every time i hit a low e it was just a wave of crackles and no sustain whatsoever.
time for new power tubes!
mrspanky78750 1 year ago
Tubes will forever be notorious for having issues. Solid state equipment has much less issues but the tone isn't the same. As for me, I'm willing to deal with the troubles and have great tone.
TubeDepotTV 1 year ago
exactly.
mrspanky78750 1 year ago
HEY!, that's no dangerous????(touch that with your hand)
omarfusion 2 years ago
I choose to only touch the non-dangerous parts. I've touched the dangerous parts (by accident of course) and it isn't very pleasant.
TubeDepotTV 2 years ago
Now that I think about it using old microphonic tubes that nobody wants anymore with a microphone as an effect you put in a box, screwed onto the inside of a cabinet with an external on/off switch and a volume treadle would be a kinda cool...
Add some sustaining Fuzz like a Big Muff Pi and some digital massive cave type reverb and it would be a great effect for drone music.
ExperimentalHaven 2 years ago
Found one of these in an old Sunn amplifier once that the owner didn't know about when he was selling it.
He said he would replace it and call me back.
How much do you want to bet he replaced it and realized why the amplifier didn't sound amazing for him?
Hilarious how you just found that out of nowhere in the middle of a video shoot.
Great videos.
ExperimentalHaven 2 years ago
In my other microphonic tube video, I discover a microphonic preamp tube in the middle of playing. Same sort of off-the-cuff excitement, check it out.
TubeDepotTV 2 years ago
I'm oddly entertained by how much fun you are having tapping the microphonic tube.
Like a kitten with a ball of yarn haha.
ExperimentalHaven 2 years ago
I'm standing there trying to think of how I can make this boinging sound into something useful ... hmmmm
TubeDepotTV 2 years ago
Faox Spring Reverb? haha
ExperimentalHaven 2 years ago
I have an earlier video where I discover a microphonic preamp tube right in the middle of playing. I was just playing along and the "drone" of the tube overwhelmed the amp. Check that one out.
TubeDepotTV 2 years ago
@TubeDepotTV
I watched it as it was very entertaining.
I used to have a .50 Caliber + that your Mark IV made me reminisce of it.
I might make a craigslist ad for that effect idea haha "Will buy microphonic tubes for 1 USD each."
ExperimentalHaven 2 years ago
I used to have a 50 Cal+ as well. Bought it brand new in 1988. I believe that was my first experience with tube troubles ... it was a bad EL84 at that time. Tubes still have the same troubles but wow they sound good!
TubeDepotTV 2 years ago
it's somewhere between Eb and E natural...how convenient
Chromatype 2 years ago
Yea ... exactly ... tough on a guitarist when we play in the key of E so often.
TubeDepotTV 2 years ago
your videos are great! especially the "How to Solder" thanks for taking the time to create these!
I'm ordering a shirt! :)
dcabinet 2 years ago
actually... I ended up ordering a shirt, picks and a v30 speaker! your prices are fantastic!
dcabinet 2 years ago
awesome .. so how did the speaker sound in your amp?
TubeDepotTV 2 years ago
one word - awesome!! Thanks again.
dcabinet 2 years ago
I'm just glad I could be of assistance. If you need anything, just ask me.
TubeDepotTV 2 years ago
lol, it sounds like the filiment might be twanging around
windoes98se 2 years ago
Exactly ... it is crazy sounding. Sadly, I've spent hours troubleshooting an amp before only to find that the weird sound was a microphonic power tube. If you come across one of these, I strongly recommend replacing it quickly. Otherwise it may drive you crazy with the silly overtones.
TubeDepotTV 2 years ago
I have a precarious solution for that, but it works. Some ago I reasoned that if the spacer are loose inside they need to be re-tighten. Well how do you do that? Simple: since there is vacuum in the tubes you can torch them. Torch them? Yes sir. You use a small plummer's torch on the spots you see moving inside the tube and the glass will bent towards it because of the vacuum inside.
alcram 2 years ago
Very cool.
Could you post a short video on how to discharge power from capacitors so they can be replaced.
iain42 2 years ago
I am working on this video now. In addition to the video, I also describe how to build a simple and safe shorting probe as well as a little about how to properly form filter caps.
TubeDepotTV 2 years ago