Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: DirectAssault on October 12, 2020, 12:15:43 PM
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Hey Guys,
I've had my Crack for years now. Probably one of my first soldering projects I've done. Then a few years back and put the speedball upgrade on it.
Recently I've noticed that I can hear a what I can describe as a ticking, popping, and crackling noise from my headphones when I turn my volume up. It's not really noticeable when something is playing, however it's hard when songs are transitioning or when nothing is playing on them. I'm assuming its some sort of power supply related issue, or something wrong with a resistor or capacitor.
Unfortunately a break in a few weeks ago have left me without my voltmeter and soldering station, which I'm currently in the process of replacing. So I'm not able to do the readings right this minute on anything. Can someone with more knowledge than myself tell me if I'm on the right track, what I can check when I do get the replacement stolen items, and how SOL I might be?
Looking at the documents, my speedball was purchased in 2017, and the crack from 2013. Or at least that's the revision for my documents. I have everything labelled on my sheet metal accordingly if someone can just tell me the #/page to look for.
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I'm assuming its some sort of power supply related issue, or something wrong with a resistor or capacitor.
No.
Unfortunately a break in a few weeks ago have left me without my voltmeter and soldering station, which I'm currently in the process of replacing. So I'm not able to do the readings right this minute on anything. Can someone with more knowledge than myself tell me if I'm on the right track, what I can check when I do get the replacement stolen items, and how SOL I might be?
Sorry about the break-in. When you get a replacement DVM, there are voltages listed on page 28 of the manual.
Do you get this noise with nothing plugged into your Crack? What source are you using?
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Do you get this noise with nothing plugged into your Crack? What source are you using?
I'm not sure what this is asking -- the noise is only audible when I have my headphones plugged in at a moderate volume, assuming that answers the question. the source comes from an external DAC, which is hooked up to my computer.
Did you mean pages 38 and not 28?
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He’s asking you what happens if you don’t have the DAC plugged in but you do have the headphones plugged in.
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Also, is your DAC USB powered?
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Also, is your DAC USB powered?
No. it's an older Schitt Modi. Optical Input, uses a wall wart for power.
He’s asking you what happens if you don’t have the DAC plugged in but you do have the headphones plugged in.
No change, same thing
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... a ticking, popping, and crackling noise from my headphones when I turn my volume up.
I wonder if it might be oxidation or some other build-up in volume pot? I think that usually manifests as crackling when turning the pot, not with the pot fixed at a certain level. But it might be worth turning the pot up and down all the way about a 100 times when the amp is off just to see if it helps.
If it were my amp, the next thing I'd try would be reheating all the joints. Years of expansion/contraction from heating up -and cooling down might have loosened a not-so perfect solder joint somewhere.
cheers, Derek
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Just to continue clarifying, you mentioned that there's noise when you turn the amp up, is that noise when adjusting the volume control? Noise when you turn the volume all the way up?
You could also try this mod:
https://forum.bottlehead.com/index.php?topic=11676.0 (https://forum.bottlehead.com/index.php?topic=11676.0)
If a new component is polluting your powerlines a bit, that will help.
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Just to continue clarifying, you mentioned that there's noise when you turn the amp up, is that noise when adjusting the volume control? Noise when you turn the volume all the way up?
The noise is present at all volume levels, but isn't really noticeable when the volume is low and is very prevalent at a "normal" audio level.
You could also try this mod:
https://forum.bottlehead.com/index.php?topic=11676.0
None of the components are new, things have remained the same for at least the last 3 years. but there wouldn't be harm to ty to cleanup some of the noise polution my system might be introducing to the line once I address the more pressing concern of the clicking
If it were my amp, the next thing I'd try would be reheating all the joints. Years of expansion/contraction from heating up -and cooling down might have loosened a not-so perfect solder joint somewhere.
I'm hoping that when I get some of my stuff recovered I'm able to do this. Wouldn't incorrect voltages or resistances be a byproduct of this though? I wouldn't have an issue redoing some of the joints if the voltmeter would display an incorrect value -- assuming it would show up at this point?
I wonder if it might be oxidation or some other build-up in volume pot? I think that usually manifests as crackling when turning the pot, not with the pot fixed at a certain level. But it might be worth turning the pot up and down all the way about a 100 times when the amp is off just to see if it helps.
i can try, there's no harm in playing around with knobs ;D
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You could have many bad solder joints and perfect DC voltages.
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You could have many bad solder joints and perfect DC voltages.
Interesting. I'm supposed to have some replacement stuff by the end of the week. Should I just go ahead and reheat all the joints anyway? Regardless of correct voltages?
Now that I listened to it at a much louder audio level, It's actually just clicking from my left ear piece. My tinnitus in my right ear just threw me off.
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What are you replacing and why?
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What are you replacing and why?
my answer:
Unfortunately a break in a few weeks ago have left me without my voltmeter and soldering station...
Sorry for not being clear.
Do you agree with me reheating all the joints again? or what do you propose?
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Two other things you might try:
(1) Clean the tube pins. And then insert, remove, reinsert the tubes a few times to scrape off any grunge/oxidation in the pin sockets.
(2) Try different tubes -- if you are using the original tubes that came with the kit in 2013, it's conceivable that one side of a tube is going a bit wonky with age. Worst case scenario: that's not the issue, and you end up with a second set of tubes and can tube roll.
cheers, Derek
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Delete the DAC and feed the Crack directly from the PC headphone jack and see if that changes, or solves the problem.
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Clean the tube pins
Best way to accomplish this?
Try different tubes
I currently only have the original tubes, I heard that replacements are a bit pricey :P
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Delete the DAC and feed the Crack directly from the PC headphone jack and see if that changes, or solves the problem.
This was already attempted, I disconnected the DAC from the amp and just had the amp headphone plugged in, the problem persisted.
He’s asking you what happens if you don’t have the DAC plugged in but you do have the headphones plugged in.
No change, same thing
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Best way to accomplish this?
See here: http://forum.bottlehead.com/index.php?topic=8888.msg84089#msg84089 (http://forum.bottlehead.com/index.php?topic=8888.msg84089#msg84089)
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See here: http://forum.bottlehead.com/index.php?topic=8888.msg84089#msg84089
I'll keep that in mind when I go out shopping :)
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So I got my voltmeter and I'm currently testing things out;
I'm looking at the terminal resistances, and everything is normal except for 3 terminals.
Terminal 22 I get a value of 1 Ohm instead of 0.
And Terminal 7 and 9 are really off, I got a value of 9 Mega Ohms (the value keeps climbing up) and 5 Mega Ohms (the value keeps climbing up) respectively. Neither the values I mentioned on 7 or 9 were the original starting values, just when I stopped checking because I needed to get my girlfriend to look at the voltmeter too, along with changing the probes out. I think they both started at around 4/6ish. Considering the large discrepancy, I am hoping that these are expected values with the Speedball mod installed.
I'll probably stop here and not check voltages until I get some sort of response :)
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The Speedball will alter the resistances at 7 and 9.
1 is very close to 0.
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The Speedball will alter the resistances at 7 and 9.
1 is very close to 0.
It'll take that as a blessing to continue...
A6 has a voltage of 70 instead of 90.
A3 has 1.5V instead of 0
B1/B4 has 70 instead of 90
All other voltages checkout, including voltages checking out on the speedball upgrades.
@PB What am I advised to try next? Reheat all of my joints? Try out the mod you linked earlier?
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A3 is supposed to be 1.5V.
70V at B1/B4/A6 is within the acceptable range.