Wildly fluttering woofer


Without any kind of warning the left woofer of my Thiel 7.2 speaker started fluttering-the excursion was at least two inches. Won't happen with a CD. Tried another record and the same thing happened again. I have not switched speaker cables.
System: VPI Mark IV turntable with Graham Phantom arm and Dynavector XX2 cartridge, McCormack DNA 500 amp, Audible Illusions Modulus 3B pre-amp, Thiel 7.2 speakers, all wires are Audience. HELP!
katz1
Did you move the table recently? If not, probably something in the cartridge or phono stage (tubes?).
Its not a speaker cable :)

Its in either the phono section or the setup of the cartridge itself. Since its only in one channel I suspect the phono section, which may have a noisy tube.
It sounds like subsonic feedback. Move the speakers to see if it improves. Also try to isolate the turntable.

You can easily isolate the problem by swapping channels from the speakers back to the turntable.
It is almost certainly sub sonic feedback as mentioned before. I have seen this using test records on my own gear which can't produce a sound below 28 cycles but will wobble violently between 20 and 26 cycles.
Thanks for your suggestions. I've recently movedy speakers and placed components on a new rack. Soon after there was some stylus instability/wobbling. I placed three products from Herbie's Audio Lab and cured the problem. I sent my Audible Illusions pre amp back to Art to check it out. Anticipating a wait, I found a Yamaha C60 preamp,used of course, to tide me over. I timidly tried some vinyl and no flutter. ALSO, my cartridge was tracking much to heavy. I'm hoping Art finds a problem with the preamp that he can fix and with the other steps I've taken I can listen without fear of a woofer fatality.
So the problem was not feedback.

A noisy tube in the phono section is still at the top of the list.
Still could be feedback. The replacement preamp may have a built in subsonic (rumble) filter or simply not have the low end response that the Audible Illusions had. Herbie's audio lab sells isolation devices, that curing the problem implies feedback was the issue.
BTW-The original post failed to mention a key issue-"recently moved speakers and placed components on a new rack". That says it all. Much different than "without any kind of warning".
Rolling tubes in the preamp may alleviate the problem as well, if the new tubes have a "thinner" sound. A "military" tube might be a better solution, they're less microphonic by nature because they're built tougher with extra support rods and mica's. The bottles may also be shorter and more compact, less likely to sympathize at the offending frequency.

Regardless, it was a learning experience.
Dear Heyraz, After all the repositioning everything was fine for the two weeks after I installed Herbies devices. I'm waiting to hear how the preamp checks out. Thank you for taking the time. Katz1
While you're waiting for your preamp to come back, you might find some of these tools at the Vinyl Engine website interesting.

http://www.vinylengine.com/cartridge_database_tools.php
Heyraz, the argument against feedback is that when it was happening, it was only in one channel. If it was mechanical feedback it would have been in both channels. The two phono channels of the preamp are right next to each other.
Cartridge and arm mismatch will cause that problem. I would blow woofers all the time. You have to find out what the arm is resonating at. Get a good test record. I use a Shure audio obstacle course ERA 4 to check mine.
Atmasphere,
valid point, but I didn't know if the offending speaker was right next to the turntable or not. That's a great way to create feedback. I also didn't know if the speakers were in phase. If it happened to me I would have reversed channels via the interconnects between each component till I isolated the problem. Or try another tube as you suggested, but I got the impression the original poster wasn't very hands on.
As far as a noisy tube goes, I don't know how his preamp is designed (tubes carrying both channels or one). The problem seemed subsonic and only in one channel, which rules out the power supply (unless it's completely dual mono). There was no mention of how much volume, if any was required to cause the problem.
The problem actually sounded more like motorboating in one channel to me, which points to an amplifier's feedback loop, and a bigger problem than a noisy tube.
There just wasn't enough information to formulate a reasonable cause as there was no mention of a process of elimination.

I'm interested in the outcome.
Dear Heyraz, " I got the impression the original poster wasn't very hands on" is almost a compliment. I'm limited in knowledge and mobility due to a broken foot and a cast up to my knee and told no weight bearing. It was too difficult for me to reverse speaker cables which was my first thought. Somehow the tracking force was almost 2.6 gms which is strange since I'm the only person allowed to touch anything. I double checked the tracking force and set it to 2.0 gms. The arm is a Graham Phantom. Using a Yamaha C 60 preamp and correct tracking force there isn't any flutter. I'm hoping Art Ferris finds a problem with the preamp I sent him.
Thanks to everyone who offered their knowledge to "hands on". I'll post Art's comments when I hear from him. Katz1
Ouch! Wishing you a quick recovery. Enjoy the music while you're stuck inside.
Dear Heyraz, I've enjoyed reading you so much that I've tracked you down via other threads. A worthwhile way to spend some of my downtime. I've never rolled a tube or changed a capacitor and I'm envious of you folks who get into the nitty-gritty of this hobby. At age 72( I'm too vain to use my hearing aids) I'm resisting my life long search for absolute musical realism with any further upgrades. I have to finally settle for good enough and stop the chase and enjoy the music and searching thrift stores in Los Angeles for the big score!
Regards, Katz1
Katz1,

Sometimes you don't have to do anything major to improve the sound. Changing stock speaker crossover capacitors is one thing that can be done easily and reversed if not satisfied.

My favorite thing about changing capacitors (any capacitor) is listening to them as they break in. At first, new capacitors usually sound horrible. After about 15 minutes they bloom as though someone opened up the door to make things clear, it's really dramatic for me, like someone raised the lights. After that, as they continue to stretch out and break in, the sound continues to get clearer, more subtle and detailed.

Rolling tubes is a little easier, no soldering involved. Different tubes have their own sound. My preamp uses three 12ax7 types in the line stage. I started out with three Telefunkens but it seemed like the sound was over-driven and sometimes too loud. So I changed the first tube to a 5751 (70% of the gain of a 12ax7) thinking I might be over-driving the second stage and the sound became less congested and more subtle. I left the tele in the second position and put a nice low distortion 7025 in the third position to smooth over and finish the sound. Kind of like finishing scotch in a sherry cask. The sound took on a different flavor. That's what rolling tubes is like for me.

I'm not as big of a tinkerer as you might think. Once I like what I hear, I'm done and just enjoy the music. It's only when I get no pleasure from listening that I wonder if it's my ears or the equipment. I can't do much about my ears, so I check the equipment or go to a friend's house to compare.

I do have an extra set of speakers that I might experiment with. They're an extra set of Large Advent's and I'm thinking of removing the internal capacitors and passing the wires to the outside of the cabinet to some terminal strips. That way I can practically change capacitors on the fly till I find my favorite. Then, using another amp, I might "stack" them to see what all the fuss is about.

How's the leg coming along? I can empathize with you're plight because I broke my neck 10 years ago and was stuck in a halo for 3 months. Thank God I had Star Trek recordings to watch, I was so bored. After that, I got hooked on The History and Discovery channels and made it a point to watch all of Clint Eastwood's movies that summer.

One day at a time..each day over is a day closer to getting the cast off.

Good luck.

Rich
I haven't checked my posting in a while hence the delayed response to your last post. Without sounding like a sycophant, your communication skills blow me away.
My left leg which has a Jones fracture of the fifth Metatarsal bone got another cast yesterday for another month. Don't know if I mentioned that I retired on April 17, bought a Honda Civic Si with six speed manual transmission two weeks later, and fractured the bone two weeks after that. So, the car sits!
According to Art Ferris at AI, my pre-amp checks out O.K. and will be returning soon. Meanwhile I can listen to music thru a Yamaha C-60 pre-amp with interestingly MM &MC(with variable loading).
Changing caps on my Thiel 7.2s is way beyond me and tube rolling sounds interesting but I'd still be hesitant to experiment. Maybe I'll run the idea past Art, although I can predict the answer. I will however engage the sub sonic filter om my 3B.
Since the pre-amp seems O.K., I have to consider that excessive tracking force may have caused the woofer flutter. Hope to hear from you again...
Thanks for taking the time to care, Katz1
That kind of fracture can take a while to heal, as you are coming to realize. Sucks about the car, I can relate. I broke my neck 7 days after purchasing a new Subaru Outback and wasn't allowed to drive it for 4 months. A couple of times I sat in it just to take in that "new car smell".

Check the capacitance setting that you're using for your cartridge, too much and it can boom. Wherever you moved your turntable may coincidentally happen to be the worst spot in the room for a turntable. Corners, for example can be boomy.

You'll figure it out. Now's the time to relax and be thankful for what you have and make the best of your situation. I felt like listening to Michael Jackson one night and recorded the playlist. I called that CD "The Halo Session". Good CD, very reflective of my mood that night.
Dear Heyraz, you might have fit another piece of the puzzle-the turntable is in a corner, I have always listened with the TT cover up/open. I too sit in the car and start the engine-it's better than nothing.
What happened to your neck and did you need surgery?
By the way, have you ever heard of the "Ukulele Orchestra of Great Britain"? Check them out on you tube.
Regards, katz1
I am going to check out Ukulele Orchestra. The name alone has my interest. Have you ever heard Vaughn Williams "Concerto for Tuba"? I couldn't resist that title.
When I landed on my head the force broke C1 into three pieces. It's called a Jefferson Crush Fracture and it's similar to what would happen to a pretzel ring if you slapped it on a table. C1 can only absorb so much force, after that it splits. A bad bop on the head is all it takes.
The C1 fracture wasn't as life threatening as the subdural hematoma, in fact the C1 issue wasn't realized for two days. I told the doctor that my neck hurt but not in the usual way (I had C5-C6-C7 fused the year before because of herniated discs). In fact, during the car ride to the ER I supported my head in my hands because it felt like it might fall off of my neck. I walked into the ER supporting my head, covered in blood looking like Carrie at the prom, and passed out shortly after.
After I awoke from the brain surgery, the doctor asked me if I had a runny nose, to which I replied "funny you should ask". He shot a picture of C1 through the roof of my open mouth which showed the C1 fracture as well as a fracture to the spenoid bone, which is behind the ocular orbits, one of which was also fractured. My "runny nose" was my cerebral spinal fluid leaking out.
Fortunately for me, I needed no further surgery, just rest and a halo to keep my head on straight so C1 could mend. Because of the trauma, the retina in my left eye also detached, but laying in bed for a few days gave it the opportunity to lay back down and re-attach by itself. That issue was realized many months later during an eye exam. I complained of blurry vision while I was in the hospital, but by the time they got an ophthalmologist to examine me, the retina had already settled back, my vision cleared up, and nothing was seen till scar tissue formed later on. The runny nose stopped by itself, and thank god my body did a great job of healing itself. I just needed food, rest and time. I was forced to take the summer off, so I adapted and made the best of the situation. No complaints, I could have easily died, or worse.
As a bonus for my pain, I got a great torque screwdriver out of the deal. It's very precise and calibrated so the halo can't be over tightened to the skull. The halo is in my shed hanging from a hook.
So take it easy and try to enjoy the down time. If you're like me, you'll come out of the gate fast once you're medically cleared. You just have to be patient.
Rich
Reading your medical story was a harrowing ride. Since I'm an atheist, and don't believe in miracles, your'e one lucky audiophile. My "pinkey" story is, hands down" almost like a burp in comparison. I hope you buy lottery tickets because it seems you buck the odds.
Whenever I need a little pick-up I give the U.O.o GB a listen on you tube. A friend in London turned me on to them two years ago and I saw them live in Santa Barbara, California a few months ago. Afterwards my wife told me I had a grin on my face for the entire concert. They were almost as good as Versed and Demerol.
My wife started a "social enterprise" called Kishe' foods about a year ago. Her goal is to support small scale coffee farmers in Guatemala and also diversify their sources of income. It's a giant undertaking as my wife(2nd) has no prior business experience. We have 37,500.00 lbs. of green coffee arriving on the west coast in two weeks and we're still trying to develop a marketing plan. Please visit kishefoods.com and check out the web site she's building. Let me know what you think. We could use your writing skills.
katz1
The big thing around here is Rook Coffee Roasters
http://www.rookcoffeeroasters.com/

There's one not too far from my house. Not at all fancy, it operates out of a converted garage. No tables or chairs, it's take out only. Unbelievably popular, never enough parking and the lines are out the door. Patrons are of all types, students, yuppies, executives, professionals and construction workers.

I don't get it myself, but my daughter thinks it's the bee's knees. These places are rolling in cash.

Me...I'm happy with a cup of Maxwell House, a crossword puzzle and my turntable.

Good luck!
Thanks for the Rook information. We might send them a sample of our Speciatly organic Guatamalan beans. Every lead is an opportunity worrh exploring.
Meanwhile no word when my 3B or the SDS from VPI will arrive. I can listen thru the Yamaha C 60 but the air and holographic sense are missing.
Regards, katz1
When you get your equipment back, you'll appreciate it all the more.
If you need someone to proof read your website, I can ask my daughter, she's very good. She majored in English (which most people think is a worthless major unless you're going to become a teacher) but knows the rules (every language has it's rules) and works for an event planning company. She impressed her boss during the interview when she corrected a document and explained why. I'm always asking her things like "what's the difference between "paid" and "payed" or when to use a semi-colon. She's having a hip surgery next month and will be idled for 6 weeks. If she's like me, she'll be looking for things to do.

You said I was lucky, but you didn't get the full story.
A year before I had my accident I had two levels of my cervical spine fused. There were three options I could choose from.
1.Steel cage inserted between each vertebrae
2.Bone spacer from cadaver
3.Bone spacer from my hip
Very often, the also screw a plate across the fused vertebrae to keep things in place while the bones fuse together.
Since the first method was fairly new, I had my reservations, I opted for the third method because it's been tried and true for more than fifty years and I didn't mind a little extra discomfort.
I told the surgeon "no screws or metal in my neck please. Who knows, maybe I'll have a car accident in 20 years and my neck breaks wrong because there was metal in it".
During my convalescence I read about a woman who used the first method (cage) and suffered the same crush injury as mine. Unfortunately for her, the cage collapsed under pressure and she required further surgery.
Another bullet dodged.
I was out of work for a month and went crazy. When I broke my neck a year later and found out I'd be out 4 months, I rolled over in the hospital bed and thought to myself "I barely made it one month, how am I going to do four?"
I wouldn't call myself an atheist, but I would say that I don't have the capacity to understand a god if there is one. I use the analogy "Is the line on a piece of paper aware that I put it there?" I just don't think it's possible for us to know why or what purpose we serve in the grand scheme. When people ask me what I think the purpose of life is, I tell them it's to have fun. Simply enjoy the gift while you can.
I was very lucky that night. My son had a funny feeling and came looking for me. He found me within 154 minutes of my fall. I could barely crawl so he helped me into the house and called my brother for a ride to the ER. If he hadn't found me, I probably would have died right there during the night. At the hospital no one suspected my neck was broken, and luckily my head wasn't tipped back when they intubated me for the craniotomy. Everything that needed to go right did, and anything that could have gone wrong didn't. I was extremely lucky and realized it immediately. I could have easily been a quadriplegic, worse than death to me.
After my accident, I have enjoyed every day off as if it were my last. That's how fast things can happen. In my line of work (pharmacist) I meet a lot of people. Some get a lucky break, some things just go wrong for others. Those that catch the lucky break are in "The almost dead club".
I can't complain, I have no right to.

Keep getting better! It ain't so bad, you just adapt and find other things to do.
Rich, I would like to be able to continue this dialogue off site. You could try [email protected]. Hope to hear from you.
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