Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: Colonl_Charisma on August 29, 2020, 08:28:35 PM
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Hi Everyone,
I just finished my very first Crack build (no speedball upgrade yet). After turning the amp on with my headphones plugged in I heard a distinct pop come from the right channel of my HD600s. Instead of turning the system off and investigating I put my headphones on and played a song and heard music in both channels which was followed by another pop in the right channel and no sound from the right channel. Do you guys have any thoughts about what may be causing this to occur?
All resistance and voltage checks passed prior to powering the system on for the first time, and I can repeat them and post numbers if you guys would like me to. Both LEDs at the 9-pin are glowing. I also tried cleaning up the RCA right input (there was and maybe still is some excess solder on it). If pictures are needed of any place on the amp just let me know.
I appreciate the help!
*My HD600s are fine. I plugged them into my solid-state amp, and the sound in both channels was normal.
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This could be a problem with your ground path.
Check the connections on the headphone jack (i'd reflow all). And reflow all (black wire) ground connections.
Redo resistance and voltage checks.
Start crack first time without headphones plugged in. Do the 10s start up test to see if voltages at the jack don't climb too high. Don't know if this last step is still in the newer revisions of the manual (was there in 2013 with my Crack).
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Had this happen once not long after my build. Turned out that one end of an led wasn't making proper contact, touching but not soldered. Easy fix.
Also check capacitor connections.
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Thank you Deluk and Tom-S! I will try both solutions probably tomorrow (no time today), and I will post back here regarding the success.
The 10s start up test at the jack is not included in the updated manual. Would you mind telling me exactly how to do it? This is something that seems worth checking.
I appreciate the help!
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The ten second start-up test is no longer valid with the current version of the Crack because we have wired the jack to short out that voltage during power up when no headphones are plugged in.
You could definitely post some build photos, my money would be on solder joints that aren't solid making intermittent connections.
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Thanks Paul! That is good to know about the 10s test. I'll post some pictures tomorrow when I can get to my Crack.
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I touched up some joints, and I actually discovered that I had failed to solder a joint. However, I am now failing my voltage checks.
I passed all resistance checks. The only voltage check I failed was terminal 7. I am getting 0.00 on my meter. Resistance was 2.8 ohms at terminal 7. Any idea what could be the issue?
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Voltage numbers after retouching some joints and adding solder to 5L (this is the terminal joint that I forgot to solder):
Terminal 1 = 79 V
T. 2 = 195 V
T. 3 = 0 V
T. 4 = 195 V
T. 5 = 84 V
T. 6 = 0 V
T. 7 = 0 V
T. 8 = 0 V
T. 9 = 117 V
T. 10 = 0 V
I've also posted some pictures of Terminal 7 and my headphone jack.
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There are other things that can cause 0V at terminal 7 than just terminal 7 itself.
How is the DC resistance at terminal 7? What number does it actually give you?
Can you post some less zoomed in photos of the whole build?
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I'll just say that this is the first time ever here that someone was told their close up photos were too tight. ;D
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Hi Paul and Doc B,
I appreciate all of the help! Doc, that is very funny that my pics were too zoomed haha. I do want to say this project has been very enjoyable, and I know troubleshooting is part of the process.
Paul, my DC resistance at terminal 7 measured 2.9K ohms when I performed my last resistance check last night.
I have attached a number of photos of my build including an overhead shot that encompasses the entire build. I included shots of my 9-pin, 8-pin, and various angles of the build. Let me know if you need a shot at a specific angle.
All the best!
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Your solder joint at A5 could definitely cause some problems.
Otherwise, things that would make terminal 7 0V:
B1 and terminal 5 are connected by a wire and should have the same DC voltage. If they don't, that could be a problem. The wire at B1 could be wrapped around the tube socket contact and crimped around it. All your connections should be crimped on the terminals/socket pins if possible.
Either end of the 3K resistor between terminal 3 and 7 not being well connected would cause this issue. Resistance checks should catch that.
A backwards cap at 6/7 would cause 0V at 7, but that's not what's going on here.
Miswiring the connection that goes from 6 to the headphone jack and instead sending it from 7 to the headphone jack will make 0V at terminal 7. It will also do so much more damage that it can't be what's going on.
The wire from 7 to B3 could be broken or not well connected. B3 should show the same DC resistance that 7 does, could you double check that?
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Hi Paul,
A5 was definitely an issue. I re-soldered the joint, and afterwards got a voltage reading of 101V at terminal 7. I passed all voltage checks this time. I also passed all resistance checks prior to doing my voltage checks. Terminal 7 and B3 had the same resistance of 2.9K ohms.
However, I am still getting a loud pop from my headphone's right channel followed by no sound after ~10s past powering the system. Left channel sounds great though! Haha.
UPDATE: After getting the pop I decided to see if my system could pass all resistance and voltage checks. Resistance checks I passed (T7 and B3 measured 2.9K in resistance too), but I failed my voltage check at terminal 7 again. It is reading 0V. I thought this might be some useful info. LEDs are still working and tubes are glowing.
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What are all the voltages?
I suspect you just have other solder joints that aren't 100%. You could likely reflow them all in under an hour.
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Hi Paul,
I re-touched my solder joints and went through the resistance checks and voltage checks. I passed them all!
Here are my resistances and voltages per my multimeter:
T1 = * ohms, 75 V
T2 = * ohms, 175 V
T3 = 0 ohms, 0 V
T4 = * ohms, 175 V
T5 = * ohms, 79 V
T6 = 0 ohms, 0 V
T7 = 2.8K ohms, 102 V
T8 = 0 ohms, 0 V
T9 = 2.9K ohms, 117 V
T10 = 0 ohms, 0 V
T12 = 0 ohms
T13 = * ohms
T14 = 0 ohms
T20 = 0 ohms
T22 = 0 ohms
B3 = 2.8K ohms
B6 = 2.9K ohms
RCA Center Pin Right = 95.4K ohms, Left = 96.1K ohms
Ground Tab = 0 ohms (both left & right)
I am going to power the system on. Will update regarding the result.
UPDATE: Upon powering on the system the pop occurred again. However, this time I noticed that a blue charge occurred inside the GE 6080 tube triggering the audible pop from the headphones. I should note that I am not wearing the headphones when I power the system on. I was paying close attention to the tubes this time to see if I saw anything, and the blue charge and pop occurred right when the 6080 tube began to glow (few seconds after powering it on). I unplugged my headphones and gear after powering off the system. I turned the system back on with no gear attached to it, and the blue charge occurred in the middle of the 6080 tube. Hopefully, this is some useful information!
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Can you leave the Crack running for a couple of days, then try again? There could be a tiny bit of gas in the 6080 that is causing an arc at startup, but you should be able to get that to go away if you cook the tube in for a good long while.
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Thanks Paul! I appreciate your help. I'm going to do my resistance and voltage checks again. Once those pass, I will start the system with no gear connected in order to let the tubes burn. I'll post an update in a day or two.
UPDATE: I have let the tubes burn all day, and I was curious to see if anything changed after powering the system up. I have attached a gif of my GE 6080 tube so that you could see what is occurring a few seconds after powering the system on. As you can see the left and right sides of the 6080 tube begin to glow blue and then a blue flash occurs. Shortly after a spark appears near the bottom left. After the tube flashes it appears normal and has a warm glow. I apologize for the poor quality of the gif, but the quality decreased changing from .mov to .gif.
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Hi Paul,
I have let the system and tubes run for over 24 hours now. I let the system cool for about an hour, powered it back on, and my 6080 tube glows blue on the glass sides right when the tube begins to glow, and once the blue on either side of the tube reaches a threshold a bright flash occurs followed by some sparks/charges in the middle of the tube. Do you think I have a bad 6080 tube? If you think I need to check any specific area of the system let me know. I also posted a gif above to show what this looks like.
I appreciate all the help!
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Let the tube run for a couple of day, let's say 5. If this gas is to be absorbed by the getter, it will take some time!
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Right on! I'll let them burn for a few days.
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Hi Paul,
So I was able to use another GE 6080 tube in my amplifier. I did this to have a control in order to rule out either a bad tube or if there is something wrong with the amp that I assembled. The new 6080 tube that I put in was used and it also tested well on a tube tester so I knew beforehand there was nothing wrong with it. Upon powering the system on there was the same blue glow with a bright flash from the 6080 tube. I believe this rules out a bad tube, and I think I should direct my attention to the amp. Also, LEDs still turn on.
I went ahead and did my resistance and voltage checks again:
T1 = 3.65 M ohms, 77.2 V
T2 = 2.65 M ohms, 177.2 V
T3 = 0 ohms, 0 V
T4 = 2.15 M ohms, 177.4 V
T5 = 2.07 M ohms, 80.6 V
T6 = 0 ohms, 0 V
T7 = 2.92 K ohms, 102.9 V
T8 = 0 ohms, 0 V
T9 = 2.95 K ohms, 107.1 V
T10 = 0 ohms, 0 V
T12 = 0 ohms
T13 = 4.33 M ohms
T14 = 0 ohms
T20 = 0 ohms
T22 = 0 ohms
B3 = 2.98 K ohms
B6 = 2.98 K ohms
RCA Jacks
Center Pin L = 95.3 K ohms, R = 94.5 K ohms
Ground Tab L = 0 ohms, R = 0 ohms
Let me know what you think I should try. Thank you again for your help!
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Tell me about the solder you used and whether you used any extra flux with your build...
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I attached a pic of the solder that I used during assembly. It says that it is 60/40 rosin-core solder for PC work. I made sure to get this kind because that was what was recommended in the manual. I did not use any extra flux during my assembly.
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Likely won't fix things, but it's easy and worth a shot: take the chassis out of the base and hold it at lots different angles while shaking/banging it (without tubes) to clear any stray lead clippings that might be lodged somewhere they shouldn't be. They can end up anywhere. When I rebuilt one of my amps, I found a bunch of lead clippings in the power transformer end bell.
If that doesn't work, you're best bet is probably to reflow every joint - including the hard to reach ones. What almost everyone does (i've been guilty of same) is reflow only the ones that are easy to get at.
cheers and good luck, Derek
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Hi Derek,
Did the shaking, but nothing came out or loose. The only solder joint that I have not reflowed is 3L. I cannot really see it very well or get to it. Trying to figure out how to do it. I appreciate the help!
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I'm glad to see that you used the recommended solder and no extra flux. You could definitely create the problem that you're having by using the wrong soldering projects.
I would get a wooden chopstick and run the amp with a cheap pair of headphones plugged in, then poke around the circuit until you actuate the pop. That will help you focus your efforts on what's loose.
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Thanks PB! I will look around for a cheap pair of cans. I may have to go out and get a pair that I don't mind potentially breaking. For clarification, I turn the system on with tubes connected and poke each soldered joint with a chopstick until I hear something unusual from the headphones? Also, should I be playing music or play nothing and only listen for a pop/noise?
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Yes, and no, you definitely don't want music playing, as you want to be able to hear the pop.
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I appreciate your help! May be a couple of days before I post back. Any recommendations on a cheap pair of cans that comes with a 1/4" adapter?
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https://www.amazon.com/OneOdio-Adapter-Free-Headphones-Professional-Telescopic/dp/B01N6ZJH96/ref=sr_1_17_sspa?dchild=1&keywords=headphones&qid=1599673416&sr=8-17-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExSzYzVjJBQ0VKOVNOJmVuY3J5cHRlZElkPUEwOTQ2OTczNkpXSjI2SzcxQUY4JmVuY3J5cHRlZEFkSWQ9QTAwOTE5NjcxTVA1QkMzWVU4UjAzJndpZGdldE5hbWU9c3BfYnRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ== (https://www.amazon.com/OneOdio-Adapter-Free-Headphones-Professional-Telescopic/dp/B01N6ZJH96/ref=sr_1_17_sspa?dchild=1&keywords=headphones&qid=1599673416&sr=8-17-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExSzYzVjJBQ0VKOVNOJmVuY3J5cHRlZElkPUEwOTQ2OTczNkpXSjI2SzcxQUY4JmVuY3J5cHRlZEFkSWQ9QTAwOTE5NjcxTVA1QkMzWVU4UjAzJndpZGdldE5hbWU9c3BfYnRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==)
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vs...
https://www.amazon.com/Aurum-Cables-3-Pack-6-35mm-Adapter/dp/B00XAVOW00/ref=sr_1_3?crid=3N3PW1G77LJUA&dchild=1&keywords=1%2F4+to+1%2F8+headphone+adapter&qid=1599673462&sprefix=1%2F4%22+to+1%2F8%22%2Caps%2C211&sr=8-3 (https://www.amazon.com/Aurum-Cables-3-Pack-6-35mm-Adapter/dp/B00XAVOW00/ref=sr_1_3?crid=3N3PW1G77LJUA&dchild=1&keywords=1%2F4+to+1%2F8+headphone+adapter&qid=1599673462&sprefix=1%2F4%22+to+1%2F8%22%2Caps%2C211&sr=8-3)
https://www.amazon.com/Maxell-190319-Stereo-Headphone-Packaging/dp/B01I4JRBBE/ref=sr_1_1?dchild=1&keywords=headphones&qid=1599673518&refinements=p_85%3A2470955011&rnid=2470954011&rps=1&sr=8-1 (https://www.amazon.com/Maxell-190319-Stereo-Headphone-Packaging/dp/B01I4JRBBE/ref=sr_1_1?dchild=1&keywords=headphones&qid=1599673518&refinements=p_85%3A2470955011&rnid=2470954011&rps=1&sr=8-1)
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I appreciate it! I went ahead and ordered the second option (Maxwell + 1/4" adapters). I'll grab some takeout and get an extra pair of chopsticks while I'm out later haha.
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I thought of another question to ask. How important is it to crimp the wires around joints? I originally did not do that very well. I have gone back to crimp as many as I could and then applied more solder to the joint. There are still some areas where this could be done.
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The crimp makes the joint a lot more reliable, but it's certainly not 100% possible to do this on every joint.
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Crimping on the wires is made much easier with suitable miniature pliers of various types. Pay a little extra for better made items. Many wires can be pre bent with fine pointed needle nose pliers before insertion. The hook then allows the wire to be squeezed a bit before soldering. Cut off the excess as you go. Having good and suitable tools for this work makes it more satisfying. Tool junkies know the feeling. :)
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Yes, having a good pair of needle-nose pliers is game changing haha. About halfway through my assembly I went out and got a good pair. No way would I have been able to assemble the kit without them.
I will be conducting my chopstick test later today. The only area that most likely needs to be re-soldered is 3L, but I have no idea how to get to it.
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If you heat 3U enough, 3L will also get enough heat to flow out.
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Thanks Paul! I will try that later today. I will report back on the chopstick test and the re-soldering of 3L.
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Hi Paul,
Just performed the chopstick test and I did not hear any pops or noises come from the headphones. I verified the Maxwell headphones worked by plugging them into my solid-state amp and briefly playing music through them.
I had the headphones off my head during the test but held them close to an ear. I did this because I wasn't sure how loud a pop or noise would be. I also had the volume slightly turned up. Want me to crank the volume and perform the test again?
When I was inspecting all of my joints I found that pin 6 on the 8 pin is slightly broken/cracked at the base. Could this be causing my tube to arc or whatever it is doing at the startup? Could I just run some solder over it to "fill it in"? My resistances and voltages are passing each time I perform tests (I run through the checks prior to powering the system on every time).
Also, my 3L terminal looks good on soldering.
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The socket contacts are twisted in order to hold them in place, so there's nothing wrong there. Are you 100% certain you poked at all the joints? You could do this with the volume all the way up, there's no harm in trying that.
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Hi Paul,
Good to know about pin 6 on the 8 pin. I will do the test again and poke all the joints and wires with the volume all the way up. I'll update you shortly.
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Chopstick test worked. I turned the volume up and was able to get a loud pop/crack when poking the black wire connected to terminal 14U & 20U. I will re-solder those terminals real quick and power everything up to see if anything changes.
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Still getting an arc/flash from my tube. Going back to chopstick test.
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Hi Paul,
After re-touching the joints that created the pop in the headphones I cannot fix the issue of the 6080 tube arcing and causing a pop in the headphones. When having the Maxwell headphones plugged in during the chopstick test I hear a buzz in the left channel with no sound from the right channel. This is all still my original problem. Resistance and voltage checks are still looking good. The Maxwell headphones are also okay. I tested them on my other amp to make sure they weren't fried.
Probably going to send the amp to you guys for repair. I am willing to try any other tests prior to doing that. I appreciate all the help.
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You can definitely send it in for repair. I'm still 80% certain you have a loose connection. Something that can also be helpful is to take your needlenose pliers and pull on each connection a little. Sometimes they will just pop out because they aren't well soldered!
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While you are in there tugging on wires check that one isn't broken under the insulation. This usually happens not far from the striped end...John
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Thanks Paul. I'm going to reflow all joints again. On the octal socket I have 2 holes that can be filled. Should I fill both holes or is it not important? I know the manual says to fill both if both are used. I tried to only use one of the holes on all the pins.
Thanks, John. I have been wondering about that, but since all of my resistance and voltage checks are looking good I have not really looked into it.
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If there's nothing in the hole, you can leave it alone.
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Paul, is there any chance that the tubes could have been damaged by the amp? Haha this seems like wishful thinking. However, as I reported before both GE 6080 tubes that I have tried will glow blue on startup and then flash followed by some tiny sparks inside the tube. The 6080 then burns normal. I don't have another tube amp (Crack will be my first) to test the tubes to see if they work in another system.
Also, I appreciate the info regarding the double hole octal sockets. I will not add any extra solder to them.
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I haven't ever seen that happen. The only time I can remember seeing this happen is when someone didn't have their power transformer screws on tightly, then didn't get 0 ohms on the resistance check at the end of the manual for the end lugs of each 6 lug strip, so they added in wires to connect them all. That sent that particular kit on the fritz but it was OK once it was returned to normal.
When you first turn the kit on, the 6080 doesn't conduct because the cathode is cold and needs to be heated up by the filament. Generally your symptoms could be explained by a gassy 6080, but that ought to go away with use and shouldn't be an issue when you have a replacement tube. Since you have two tubes doing the same thing, that does suggest an issue with the amp itself, as damaging a tube to the point of making it gassy is going to present many other obvious issues.
Maybe a fresh shot of the wiring or two will reveal something we have missed thus far.
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I am glad to hear that. My intuition tells me that the issue lies with the amp and not the 6080 tube too.
I made a quick Imgur album of some new pics of my build. I did an overhead shot of the wiring and I included some closer shots of wiring and solder joints.
https://imgur.com/gallery/67g9Vbx
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A2 looks pretty suspect to me. Wrapping and crimping leads where you can will form joints that are more solid. Naturally you could also swap the 12AU7, but a 12AU7 that would make issues like that should come with major DC voltage issues.
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Thanks PB! I will take a look at A2 tomorrow morning. If you see anything else that looks suspect let me know and I'll touch it up tomorrow.
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Hi PB,
Cleaned up A2 on the 9-pin. I used my solder wick to remove all solder from the joint. pre-crimped the wire, and then re-soldered it. It looks a lot better. However, the problem still exists. Going to do another chopstick test.
Should the holes on the 9-pin be completely filled? Mine are not.
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You really only need the solder to flow between the crimped wire and what the wire is crimped to. Filling the socket holes is not required for a solid joint.
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I performed another chopstick test with the volume turned all the way up. I was unsuccessful in locating the troublesome area. No pop or crack from headphones after pushing and pulling on wires, pushing on hardware, or pushing on joints. LEDs still glow fine, tubes burn (there is still a blue glow that then turns into a bright flash once the 6080 tube begins heating up), and resistance and voltage checks are still looking fine. I also cleaned up the octal socket. I used the solder wick to remove excess solder and I crimped wires around the octal pins. I then resoldered all of those joints.
I do have a very loud buzz in my left and right channel. Right channel always goes out after a pop/crack is heard from the right channel without me pushing or pulling on any wires. Loud buzz stays in the left channel. If I move my hand closer to the hardware then the buzzing gets louder, and if I move my hand away from the hardware the buzzing returns to a lower level.
I have no clue what else I can do.
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That could indicate loose hardware on the amp, though having some buzzing when the volume pot is all the way up and nothing is plugged in would be totally normal.
-PB
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That's fair about the buzzing probably going away once I have more things plugged in besides the headphones.
Are there any other tests I could perform? Any chance I could have a broken wire somewhere, or would the resistance and voltage checks catch that?
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The chopstick test usually catches broken wires pretty effectively. You did use the white nylon insulating washers when mounting the power transformer, right?
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If I move my hand closer to the hardware then the buzzing gets louder, and if I move my hand away from the hardware the buzzing returns to a lower level.
I would try tightening all the screws/nuts that attach the hardware. With special attention to the ground lug near the power inlet and any terminal strip to which a black wire attaches to the lug that bolts to the chassis.
If that doesn't help, I'd go over the joints with A LOT MORE HEAT and maybe remove a bit of solder (optional). I looked at the pics you posted first in this thread. Really nice, neat build. But one thing stuck out: you used lots of solder and yet almost none of the wires have melted insulation near the joint. Almost all of them look as if they were freshly cut and never exposed to heat. That's possible to achieve with really high heat and really short dwell time, but none on your joints look like high heat was involved. So I suspect you used low temp and fed a lot of solder onto the lug. If either the wire or the lug wasn't making good contact with the soldering iron tip, low temp is a recipe for a cold joint. At low temps, I can imagine the rosin core (inbuilt flux) of the solder not burning off and instead coating either the wire or the lug, whichever wasn't fully heated. That stuff is insulating.
If you have an adjustable iron, I'd crank it up to 800F and give each joint a good heating -- other than the red HLMP diode attachments.
cheers and good luck, Derek
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Thanks PB and Derek.
PB - I did use the white nylon insulating washers. I attached a photo to verify.
Derek - I did not know that the rosin core is supposed to burn off. I will go over my joints again with the highest heat setting. Joints are supposed to be shiny, correct?
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Okay, I've been reflowing/reheating my joints and I'm seeing a lot of brownish oil coming out of them. Now a lot of them are also turning shiny.
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If the brownish flux hasn't come out of the solder joints, then they were never adequately heated.
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I had no idea that I was supposed to do that haha. I was just touching my soldering iron to the joints. I realize now that I should have let it sit there for a couple of seconds. A lot of that brownish oil is coming out of every joint lol.
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I did not know that the rosin core is supposed to burn off. I will go over my joints again with the highest heat setting. Joints are supposed to be shiny, correct?
Sometime the rosin/flux just floats to the surface -- e.g., with Cardas Quad Eutectic solder -- and never burns off. But that's fine as long as its not stuck inside the joint.
As for shiny: in my limited experience, most good joints end up shiny, not not all of them -- e.g., some joints with a lot of metal mass will cool quickly and look a bit dull, even if you've used high heat, but they're sound. What I look for is the solder turning watery - not just liquid/molten, but running like water into the joint. It's easier to see when you use only a moderate amount of solder. For me, the key is make sure I am heating both the wire(s) and the terminal lug at the same time. And if multiple wires attach to the same terminal, I will often go over each wire connection separately to make sure each one gets heated properly.
I often put a tiny dab of solder on the iron tip to facilitate heat transfer (it conforms to the shape of whatever your soldering and gives you greater surface area contact -- but some people think this isn't proper practice -- it works for me -- but I only use a TINY dab). I also find it helpful to put the soldering tip on one side of the wire and apply solder to the opposite side - this way I'm not applying solder directly to the soldering tip which would instantly liquefy the solder and create the false appearance of a properly heated joint.
cheers, Derek
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The tip should be properly wetted before putting it on a new joint. Wipe the tip on your wet sponge and apply a little solder. If you are unhappy with how it looks on the tip do it again. The tip should be clean and shiny with no black or brown crusty bits. You can add a tiny bit of solder to the clean tip if needed. Apply tip to the joint and use the wetted tip to the joint. Allow it to heat up properly before adding solder so it flows into the joint. Allow it to flow into the joint fully before removing the tip. Don't dab at it or move the wire. Allow to cool for a few seconds. If reflowing a joint apply the clean and wetted tip to the joint and allow it to flow fully. You may or may not need touch with new solder.
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Thanks PB, Derek, and Deluk! I reflowed all joints last night. After a few more attempts at trying to diagnose the issue I have made no progress. I've decided to throw in the towel and send the amp to Bottlehead through their repair service. Hopefully, we can get a post from PB later down the road as to what the issue was so that it can help others in the future.
As of now, all resistance and voltage checks pass, LEDs light up and do not blink or turn off, and tubes burn.
Issues that cannot be resolved:
1) 6080 tube glows blue once it begins to heat up and once a threshold is reached the tube flashes with sparks in the center of the tube. If headphones are plugged into the amp during this time there is a very loud pop associated with the flash that comes from the headphones followed by no sound in the right channel.
2) If headphones are plugged in after the 6080 tube flashes, the right channel will cut out after a pop or crack is heard. Left channel seems to be operational.
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Unless I missed it reading through this post, did you ever replace the power tube that came with the kit? I had something similar happen. Pop in right channel and a small spark inside the power tube. Did the whole reheating routine, but still had issues, usually within minutes of startup. Finally replaced the power tube and no issues since.
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Hi Lowercase,
I did replace the stock GE 6080 tube with another GE 6080, but the same issues were still present. I ended up sending my Crack amp in for repair because I was unable to figure out the issue after re-flowing the solder joints and doing a couple chopstick tests. Once I hear back from PB I will update this forum thread as to what was causing the issue.
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Hi everyone,
I appreciate all the help that I received during this post. The issue seems to have been a bad tube. I received my amp a couple of weeks ago, and I love it. Amazing sound, and I have already started tube rolling.