Destroyed front diaphragm on a brand new K67

[granger.frederic]

Yes. I posted about them here more than 20 years ago. They are exactly as you said, there to help prevent the membrane from being too attracted to the perfectly flat backplate.

My photo that I posted on the original forum.

Thanks Tim, so I understand why they abandoned those dots... Totally useless to me, or ultra marginal effect, difficult to calibrate, maybe even counter productive...
To prevent collapsing, diaphragm tension, spacing, polarization voltage, termination type, are way more critical to me...

 

[rmburrow]

Once upon a time, I was going to purchase a Studer mixer from a guy so I went to see it at his house. He had smoked so much weed that not only were the outer mixing surfaces coated in resin, but the inner circuit boards too. I didn't think I could ever clean it well enough, and so passed on it. His weed smoking was a terrible thing to do to such a fine piece of gear.

Imagine that guy's lungs smoking all that weed. The states went after tobacco when slick willie was president and do nothing about weed...guess the politicians won't since they may be users also... with all the drug advertising on the air and weed products advertised on the air, they may as well put tobacco back on the air also since these users endorse slow motion suicide...lol

BTW cleaned up a lot of equipment and circuit boards with denatured alcohol...radio station studio gear especially a while back got coated with smoke residue from the announcers...sometimes it was easier to immerse circuit boards in denatured alcohol and see the alcohol turn brown from smoke residue...wonder how brown a few gallons of denatured alcohol would get if the faders etc. were removed from that Studer board and the entire mixer was dunked. Never use denatured alcohol on energized equipment or anywhere a discharge from a capacitor etc. could cause a spark!

Most circuit boards I have dealt with clean up nice after a session with denatured alcohol and brushing of both sides. Sometimes it is easier to replace muffin fans than clean them, especially if the bearings are noisy.

 

[Delta Sigma]

It's been a frustrating week with this U67.

More issues with it. It's acting like there isn't a proper backplate termination. Rear capsule is louder than the front in fig-8 and omni. Front diaphragm is quiet. Not an issue with the capsule as it follows/acts the same when the capsule is reversed. Figured maybe I'm not getting proper 59V at the backplate but it seems fine (expecting between 1V-2V, 520M with a 10M DVM). Initial continuity checks all seem fine. I think I have to put it away for some time because what started as an easy fun build, turned to a shit show in the end.

I had the build finished, turned it up and there was audio. Stupidly changed the pad cap (on the reed switch PCB) late at night, after a few beers. Melted the switch housing plastic with my soldering iron (cosmetic only, but yeesh) AND lost one of the little staples from that stop the switch in position. Had to bend an actual staple to replace it.

As I mentioned at the start of this thread, I tried to quickly calibrate it, left the room to do other projects around the house, without realising I bumped the generator and overdrove the front diaphragm into the backplate. Later in the same day my Zen Q died. Now the damn thing isn't working properly so I'm trying to troubleshoot it without an interface, making a mess of cables in the room.

Since I turned the capsule around, the white plastic protector on the top of the capsule is ever so very slightly offset and it was super hard to get the capsule assembly back into the grille. Before finally realising that I should simply turn the white plastic thing around so it didn't catch the grill anymore, I broke the plastic nipple on the pad switch.

I make a lot of f*ck ups, but this many on one relatively simple fun project? Melted plastic, lost switch stopper, nearly killed capsule, broken switch nipple, and the mic still doesn't work. All because I'm trying to rush, but I have no reason to rush. Probably won't learn my lesson from this either...

And a dead Zen Q on top of all that!

 

[MicMaven]

It's been a frustrating week with this U67.
. All because I'm trying to rush, but I have no reason to rush. Probably won't learn my lesson from this either...

Mah Gawd, Old Man ... that is a tragic tale. But I can relate, because I have been there more times than I want to admit and on more than just audio projects. I used to keep a note pad on the nightstand when I was working, because I would wake up in a cold sweat at 4 AM with a solution to a knotty problem, and I told clients to take two days before responding to a settlement offer because their first take is rarely the final take ... so ...

Serving Suggestion: I respectfully suggest you walk away from this project for a couple of days and let your subconscious mine solve the problem - you will awaken in a cold sweat with the solution soon - so just let it gel in your mind while you are distracted by some other tasks. And, I am NOT being critical or snarky with this - I truly do appreciate your situation! Take a day or two off. You will resolve it quickly when you return to it.

Just MY take. Good luck. James

 

[Delta Sigma]

Mah Gawd, Old Man ... that is a tragic tale. But I can relate, because I have been there more times than I want to admit and on more than just audio projects. I used to keep a note pad on the nightstand when I was working, because I would wake up in a cold sweat at 4 AM with a solution to a knotty problem, and I told clients to take two days before responding to a settlement offer because their first take is rarely the final take ... so ...

Serving Suggestion: I respectfully suggest you walk away from this project for a couple of days and let your subconscious mine solve the problem - you will awaken in a cold sweat with the solution soon - so just let it gel in your mind while you are distracted by some other tasks. And, I am NOT being critical or snarky with this - I truly do appreciate your situation! Take a day or two off. You will resolve it quickly when you return to it.

Just MY take. Good luck. James

Yeah, definitely. I know it's something obvious too. I just don't have the brain power anymore. On work callouts, I always end up figuring out the issue on a bathroom break, or driving to another site. Sometimes when the problem is staring at you, you look right past it.

 

[cyrano]

they were only banned in 2013 in the US, so her brush is likely real? if you're in europe (i see you are) i think they can be bought with paperwork.

Her brushes are at least 20 year old. A gift from her mentor, who was a 3rd generation antiques specialist. Lately he only restores wooden yachts. Fed up with antiques dealers.

AFAIK they're not banned here, just became unobtanium. Other stuff became hard to source too, like oxalic acid. You can get it if you buy it in a 250 liter barrel, but not if you only need one liter. Terrorist weapon, you know. Meanwhile, the supermarket still sells hydrochloric acid...

I came across some dead marten recently. Killed by hunters and draped over the barbwire around a meadow. These idiots still believe that will frighten other martens. I don't think anything frightens martens.

Now I wonder if I should've collected the cadavers for the fur...

 

[soapF]

Yes, we all make mistakes...
(see attached photo)

Looks like a yu-gi-oh card

 

[soapF]

Yeah, definitely. I know it's something obvious too. I just don't have the brain power anymore. On work callouts, I always end up figuring out the issue on a bathroom break, or driving to another site. Sometimes when the problem is staring at you, you look right past it.

Albert Einstein supposedly would intentionally sleep deprive himself in order to solve problems. He said something along the lines of “you can’t solve a problem with the same mindset that caused it”

 

[TimG]

Perhaps that would be called 'non-conformal' coating.

“Potted”

 

[Tubetec]

Damn ,
whats with hitting on the weed heads ,
look at what prescription meds have done to us ,
they actually shut down the human brains abillity to repair itself ,
which its been doing for millions of years without the need for man made molecules from a lab.
Lets fucking face it the best music wasnt made by dry drunks or people recovering from smack addiction ,
more frequently it was made by people caught up in the midst of addictions ,
If you cant stand the heat ,get out of the kitchen and dont bother trying to tell others how to best live their lives .

 

[Barry Hufker]

It's not about the drug use. It's about the effect it may have on the gear. No coffee spilled on the gear. No soda spilled on the gear. No alcohol spilled on the gear. No water spilled on the gear. No cigarette smoke on the gear. No weed smoke on the gear. It's that simple. After that, it's just good-natured humor... As far as I can tell no one is making a statement about drugs.

 

[kingkorg]

Damn ,
whats with hitting on the weed heads ,
look at what prescription meds have done to us ,
they actually shut down the human brains abillity to repair itself ,
which its been doing for millions of years without the need for man made molecules from a lab.
Lets fucking face it the best music wasnt made by dry drunks or people recovering from smack addiction ,
more frequently it was made by people caught up in the midst of addictions ,
If you cant stand the heat ,get out of the kitchen and dont bother trying to tell others how to best live their lives .

Now i have to read the whole thread again to try to figure out how we got to this reply

Favorite one so far

 

[MicMaven]

If you cant stand the heat ,get out of the kitchen and dont bother trying to tell others how to best live their lives .

Gee, Mr. T., ... we were only commenting on how some folks have gummed up their works smoking stiff. But, if you wanna change the topic, maybe we should take that to the Brewery ... Seriously, Old Man, we were only poking fun at how gummed up gear can get. JHR

 

[soliloqueen]

i doubt most of us were joking about his habits, or at least I wasn't, just the effect it had on his gear... everyone knows responsible engineers use edibles!

 

[Tubetec]

The stoat , the pine martin and the ferret all seem to have a common ancestry ,
The ferrit gets the badge 'domesticated' , here in Ireland they were bred to hunt rabbits by sending them down the burrows , while the men waited with nets and dogs around the other exits ,
Even under the darkest days of empire a few men could feed their families and maybe help out a few neighbours in need . The ferret will also happily take on a king rat either for the sport of onlookers or just for his own fun . A weasels piss will bring you to tears ,never handle one and not wash your hands after.

Heat is by far a bigger killer of gear than any part smoke deposition plays ,
in fact maybe a layer of nicotine tar might help prevent any kind of dust munching mite making a home in your rack , and taking a dump inside ,
I made good money out of spider mites shitting inside equipment though ,
I forget how many times I got an amp in with funky pots only to discover it was infested with mites their webs and their associated droppings .

now to jump the topic back onto the rails ,
fet based mics that run cold to the touch are far more prone to contamination from moisture , dust and airborne oils in my experience .

Im not that old James , even though some might describe my views as antiquated ,

Eating weed or edibles ,your looking at half life of around 12 hours , ie your still 50% stoned when you wake up next morning where the effects of smoking a joint wear off after only a few hours .

 

[kingkorg]

I can see some spin off threads coming. Thc vs. nicotine pre-aging diaphragms.

 

[Delta Sigma]

I can see some spin off threads coming. Thc vs. nicotine pre-aging diaphragms.

Nicotine! That's why my recordings don't sound like the Beatles!

 

[soliloqueen]

I can see some spin off threads coming. Thc vs. nicotine pre-aging diaphragms.

I just feel like weed smoke makes the diaphragms less compliant, you know?

 

[MagnetoSound]

 

[terry setter]

I was once working a late night session. Around 2AM, the studio owner (thank god it was him, not me) knocked a Dr. Pepper over, onto the board. We mopped up the worst of it and decided to call it a night. We put in a call to the tech to be there at 8AM. When we went back the next afternoon to finish the session, we were informed that the board was dead - FOREVER. The amount of corrosion that had occurred in the electronics before the tech got there was so bad that he told the owner the board could never be reliable again. It went pretty much everywhere inside the board and did it's dirty work all night long.

SO, I guess we'll have to extend that list of dangerous substances....