Bottlehead Forum
Bottlehead Kits => Crack => Topic started by: TontonFlingeur on December 17, 2013, 09:27:07 AM
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About two weeks ago I noticed a lot of static coming across both channels.
I poked around with a chopstick, and couldn't get the crackle to diminish or increase; it just stays at roughly the same volume and frequency of occurence (random).
I also ran voltage checks, and the readings are approximately halfway where they should be.
When I flipped the plate over to start digging around, I noticed that after about 10-15 minutes under power, the two big 2229As upper left quadrant were extremely hot, to such an extent that smoke is being produced by one of them.
I can't really eyeball which cap is producing the smoke, but by touch, I'd have to say it's the 14 / 15 unit, since it's too hot to hold onto for more than 2 seconds. 12 /13 is hot, but not painfully so. Same for the 20 / 21 unit.
Any thoughts? All white bands on the big caps are facing south, meaning towards the headphone jack.
My LEDs are also all red. The LEDs on B and A are very dim when compared to the two on the upper center Speedball board - those two know it's Christmas and want Rudolph's job!
One thing I have noticed is that a lot my solder joints look like crap; a crusty, corroded yellowish color, the kind of gunk you can get on a car battery terminal, or 10 days after shore leave.
I'm planning on reflowing everything, but want to hold off until more enlightened minds chime in, since it seems I end up reflowing about every 2-3 months, so my hunch is I have a deeper issue.
Thanks, all, this forum is a godsend.
-Dave
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What kind of solder did you use?
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Hello Doc,
And damn, quite the honor!
From Do it:
40/tin, 60/lead, acid core.
Best,
-Dave
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Acid core, yuck! These also tend to have conductive fluxes that bridge every adjacent contact in the entire amplifier, leading to noise, arcing, smoke, etc.
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Consider me chastised!
So, this build cannot be saved?
I could try to desolder the snot out of it, but why bother, best to start anew and afresh ....
Do you agree?
I'll trash my build.
I was hoping to make this work.
-Dave
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Pretty much. That stuff shouldn't be used for copper pipe. It's for soldering difficult metals with a torch.
Use 60 (tin), 40 (lead), rosin core for the next one. And thin ~.030" too.
Bummer.
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Consider me chastised!
So, this build cannot be saved?
I could try to desolder the snot out of it, but why bother, best to start anew and afresh ....
Do you agree?
I'll trash my build.
I was hoping to make this work.
-Dave
Water is your friend, lots and lots and lots of water.
You generally want to keep water away from the power transformer, so you'll have to get a wet toothbrush and scrub, scrub, scrub!
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I'm pretty sure I'm out of luck on this one.
I tried reflowing the joints, using the rosin core solder that Mike B recommended, and swapped out the capacitors for new ones, but still hearing the static
This is really too bad, the sound was great when everything was working well.
Thanks to all for the advice and tips.
Best,
Dave
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I'm pretty sure I'm out of luck on this one.
I tried reflowing the joints, using the rosin core solder that Mike B recommended, and swapped out the capacitors for new ones, but still hearing the static
As I said above, the flux in your plumbers' solder has deposited a conductive residue all over the place. This has to be cleaned off before the amplifier will work properly.
-PB
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You might try this, but proceed at your own risk. If it doesn't work, don't blame me.
Remove the transformer.
Put the chassis in the dishwasher parts side down on the bottom rack. Use dishwasher soap and wash just like dishes.
Let dry a couple of days and power up cautiously.
We used to put every board we did thru the dishwasher after wave solder, it won't hurt the parts. You don't want to wash the transformer though.
The acid flux will destroy every part on the plate if you don't remove it. Really I think there is little hope as acid residue will exist in the soldered joints and will work incessantly to destroy them. But hey, if it works you will get some listening time before you have to trash it.
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The dishwasher is a good recommendation (and removing the transformer is mandatory).
I'd also opt to not heat-dry the parts.
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...
I'd also opt to not heat-dry the parts.
PB, you're getting cautious in your old age! :^)
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Just ordered my first project. Where is a good place to get the right solder? and I want to buy a good solder iron, because I plan doing many more projects.
Thanks
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Many will suggest the Tenma irons. I'll suggest a nice Weller. I often post when there is a Weller Sale at MCM Electronics.
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Thank you, I will check both of them out. I think my local serviceman uses weller. Now that I know what iron to get, what kind of solder do I get? I saw the earlier post in this thread, but I thought uber hifi solder had stardust and 90% silver in it..... ;D just messin, but for real I thought solder had a little silver in it. I ordered some carda connectors one time and noticed the had solder with silver. just wondering? thanks in advance.... If there is already a thread dedicated to this please point me in the right direction.
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The best solder is 63% tin, 37% lead. No silver. Sorry.
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I use Cardas Quad Eutectic solder. I had a pound roll of 60/40 that got used up a couple of years ago. The roll from Cardas will have to be willed to someone.
Paully has used it on several builds he can attest that the Weller/Cardas combination makes quick flowing solder joints. I don't think he has had a bad solder joint on any build.
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I use 60 Sn, 40 Pb or 60 Sn, 39 Pb and 1 Cu and it always flowed greatly. I recently upgraded my soldering iron to a soldering station. This was my best buy along BH products.
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From a novice's point of view who only did his first solder joints a few weeks ago it surprised me that the Cardas Quad Eutectic solder used for the build was easier to work with than the standard 60/40 solder I used for practice.
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Thanks for all the good advice
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So I ordered a completely new kit, including the speedball upgrade, got it a couple of weeks ago, and am starting the build today.
Gotta believe the Doc is winding down operations, because the quality control just ain't there.
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So I ordered a completely new kit, including the speedball upgrade, got it a couple of weeks ago, and am starting the build today.
Gotta believe the Doc is winding down operations, because the quality control just ain't there.
I'm not exactly sure what this is supposed to mean?
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You are welcome to offer specifics. Otherwise I suspect the community will take your post as a troll.
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Sure, I'm happy to provide specifics.
The tabs on the terminal strips for both the octal and the nine-pin required trimming, they wouldn't fit otherwise.
The screw holes on the chassis for both the octal and the nine-pin needed to be enlarged.
The finition of the chassis plate was overall poor.
I've since finished the build, and there's a background mid-level pitch that persists even when the volume's at zero. The first build was dead quiet.
This second build required more tweaking of basic components, and doesn't sound as good.
If that's trolling, call me Bert.
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The tabs on the terminal strips for both the octal and the nine-pin required trimming, they wouldn't fit otherwise.
The screw holes on the chassis for both the octal and the nine-pin needed to be enlarged.
The finition of the chassis plate was overall poor.
[...] The first build was dead quiet.
The chassis plate dimensions and the terminal strips haven't changed since the introduction of the Crack. The finish, however, has changed, but can still be painted over if you don't find it to your liking.
I would suggest that the mid level pitch is an issue that may show up in the voltage checks.
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We will certainly look into the fit of the terminal strips and screws. Possibly we had a panel that was cut out of spec. I think that once in a great while the laser head shifts slightly when they are laser cut and we very occasionally see a hole that is a little off spec. I brush pretty much all of the panels myself but I certainly won't dispute than one in every few hundred might get by me. If anyone else is having this problem please let us know.
Is the mid level pitch like a higher pitched whine, or is it low like 60Hz or 120Hz hum?
Your jibe about me winding down has me chuckling to myself because we just finished the busiest year we've had in the past 20. Maybe I need a vacation.