I know the feeling having lived in S. Fla. for 25 years. If the forecaster's are close to being right it looks like this one won't be a major storm but they all spawn tornados. We'll be pulling for you guys down in the big Easy. |
.
Siltrains,
.
Good Luck with Gustav. Hopefully, it heads into the Yucatan where it might do the least damage and harm to people.
.
I know what it is like (live in Miami) and feel for you.
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Rgds,
Larry
. |
Hello Dan and Cello and thanks for the calls for good luck. What started as i would say a slow hurricane season is now heating up big time, 2 within 600 or so miles of each other. I am also hoping and praying for a hit in a area of least population.
I had the time to order etching cream and mylar yesterday. From all of your enthusiasm i am more than ready for this tweak.
I'm in the process of taking my system down and packing for evacuation if necessary with in the next 12 to 18 hours.
You guys keep the music playing and have a good labor day weekend. |
"Stilty".....Best of luck!! |
Doug, Is it 1" wide splicing tape you use? I ordered 1/2" wide splicing tape and it's not quite as wide as the Silver tape. I think I ordered the wrong tape now.
http://usrecordingmedia-store.stores.yahoo.net/1inch.html |
Frank,
I use 1" wide splicing tape. I do not use a splicing block. I get better results by matching and cutting on a small sheet of glass sitting on a clean, flat surface. YMMV of course.
Tools include a steel straightedge, an Xacto knife (a #11 blade works well) and a bunch of little post-it notes to hold the belt in position.
After cutting the overlapped ends at a 30-40 angle, I apply the 1" splicing tape ACROSS the join at the SAME angle, burnish it down with a thumbnail, then trim the excess off each side.
Easier to do than to write. Hope this helps.
|
Doug,
I've acquired a spare VPI 300RPM delrin motor pulley to machine flat in order to compare 1/2" tape to the custom thread/pulley drivetrain on my modded VPI TNT. I have a lathe, but I suppose I would need to devise a special cutting tool to make a convex surface. Do you feel a convex surface is really necessary, assuming that guide lips have been added at the outer edges to keep the tape from wandering?
Also, one thing I've noticed with my thread drive arrangement, is that frequent retensioning is necessary as the thread stretches. You can really hear liveliness & bass improve after minor retensioning. Does tape drive stretch constantly and require similar maintenance?
I've had bad luck with completely inelastic materials such as braided Stren fish line. I believe a certain amount of elasticity is necessary to "spring-load" tension into the drive system. With zero elasticity fish line, the line needs to pulled as tight as piano wire to obtain grip(at which point it rings), and even then fails to grip well due to excessive slipperiness of the coated synthetic material.
So I suppose the optimal drive belt material should have some inherent friction, a bit of elasticity, and enough physical integrity not to break down and stretch to the point that it looses its elasticity. I can always hear the improvement of switching to a new thread. I assume this is because the old thread has given up its elasticity.
Finally to the matter of batteries. I've been using large 12V SLA batteries to power the VPI AC motor through Mark Kelly's AC-1 drive controller. The same Enersys Odyssey and Optimas Yellow Tops are used to power CDP and other line-stage components in my system. I've noticed quite of bit of improvement with very low-impedance batteries, and even more improvement after adding huge amounts of filtering capacitance. If you examine internal resistance specs for SLA batteries, you'll find that only the really large (and expensive) >50AH deep-cycle batteries like the ones above achieve impedance <3 milliohms. Whether these differences can be heard in your application is unknown, but perhaps worth a try.
Dave |
Thanks Doug, I made a couple of belts yesterday and used the 1/2" splicing tape since that's what I ordered. I think it will hold just fine. It's a lot stronger than the silver splices I was using. Thanks for your continued support! |
Dave, That seems like a great idea! Good out of the box thinking. Do you feel a convex surface is really necessary, assuming that guide lips have been added at the outer edges to keep the tape from wandering? I've never tried, maybe Thom or Chris Brady would know from the early days of the Teres development group. It's worth a try, right? Worst case: you mangle a $.25 belt. Best case: you discover that the greater contact surface provides more traction (a thought that's occured to me, though we haven't tried it). Give it a try, you can always machine to convex later, right? Also, one thing I've noticed with my thread drive arrangement, is that frequent retensioning is necessary as the thread stretches. You can really hear liveliness & bass improve after minor retensioning. No doubt about it, fully agree. Does tape drive stretch constantly and require similar maintenance? Never. Motor positioning and levelling are critical and may need an occasional reset, but that's all. Mylar won't stretch under the loads we're applying. I've gone months without adjusting anything in the drive system, though last week the cat nudged the motor in the middle of the night. Grrr! The problem with your non-stretch fish line isn't that it's non-stretch. The problem is that it's too fine in cross section to have enough grip on the motor pulley. Introducing elasticity might ameliorate that, but you'd be substituting one vice for another. So I suppose the optimal drive belt material should have some inherent friction, a bit of elasticity, and enough physical integrity not to break down and stretch to the point that it looses its elasticity. Yes, no and yes, at least IME. And that's the whole point of this tweak. The texture on the back of the holographic mylar is exposed by removing the silver layer. There's your friction. No elasticity, so no damage to musical transients. No break down either, mylar is a very stable material. I've noticed quite of bit of improvement with very low-impedance batteries That's been our experience too. Paul chose the battery we're using for precisely that characteristic. Yours might be even better of course. :-) --- Comment to Galibier users: Several of you noted that, unlike our setup, you don't need to tension the belt to the motor pod's near-tipping point. Makes perfect sense. A Galibier motor pod is notably heavier than ours and also more squat in shape, so the feet are more spread out. It would take a lot more force to tip your motor than ours, probably too much and possibly risking the life of your motor bearings. |
Thanks for confirming that, Doug, about the motor pod differences. That is the conclusion I reached based on what I remember your Teres motor pod to look like.
With the Galibier motor I find that if I go real tight with the belt it will almost immediately climb the capstan. So I start there and gently relax belt tension until the belt no longer climbs. That seems to be about the best tension.
And thanks for mentioning about the dust picked up by the belt. I neglected to brush the belt between plays for 3 or 4 sides. When I brushed the inside of the belt on the 5 side I was startled at how much immediacy came back. Maybe Paul's next breakthrough should be a way to eliminate or minimize the static buildup. ;-) |
Doug, I have not yet laid hands on mylar tape, but I find it difficult to believe this material has no elasticity or even approaches the inelasticity of braided fishline. If you hold a 50" length of mylar in your hands(typical length of a TT belt), you're saying it has zero stretch when pulled at the ends? I'm not criticizing mylar, but merely exploring the point that some elasticity is inevitable and perhaps even desireable. |
Dan,
Dust buildup seems to vary with the weather. In the winter when our New England air is so dry, static builds up more and more brushing is needed. Less so in summer.
I did test static reduction in a simple and somewhat extreme way. Paul warned me it wouldn't help, but you know I never listen to him if I can make a fool of myself independently. With the platter spinning I zapped the belt with the Zerostat. INSTANT and TOTAL loss of grip between belt and platter. I could hear the belt whizzing past the slowing platter, it couldn't maintain its grip.
Dr. Chuckles wryly explained that the electrostic potential between belt molecules and platter molecules is what makes the whole system work. I knew that...
Dave,
I'm not saying mylar has no elasticity, just that the loads applied in this particular application are not high enough to reach its elastic threshhold. The "proof" is what I said above. Except for the occasional marauding cat, the motor position can be ignored for months with no change in performance or belt tension. In practical terms, it's pretty elastic-free.
BTW, the length of mylar under actual tension is not the full 50" length of the belt. Only the segment between the motor pulley and the contact area of the platter on the drive side is being tensioned.
|
Hello Paul and Doug i was able to get my mylar etched and installed today and would like to say thank you for a very good upgrade. When you have such small tweaks like this that make large improvements its a wonderful thing. |
Stltrains,
Glad to hear you're all back together after the evacuation for the hurricane, and glad you're enjoying this upgrade like the others who've tried it.
|
Dgarretson,
Further thoughts on your implementation of a VPI idler wheel as a pulley for a 1/2" wide belt...
Clearly this will necessitate running your motor at vastly reduced RPM's. Assuming your controller has the range to allow this, you still run the risk of exaggerating the audible effects of your motor's cogging behavior. As the ratio between motor RPM and platter RPM approaches 1:1, motor cogging is directly translated to platter cogging.
By all means go ahead and try. But if you aren't happy with the results the fault may lie with the motor and the large pulley, not the belt. A way to test that would be to machine a small diameter pulley and use it with the same 1/2" belt. The faster the motor runs (relative to the platter) the less audible motor cogging will be.
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Doug,
Are you suggesting that cogging effects may be greater with 1/2" tape than with the thread drive I'm currently using, owing to improved grip of tape? I had considered this possibility when earlier converting VPI from soft rubber belt to thread. But there was nothing but improvement. So perhaps this experiment with tape will determine if too much grip is a bad thing with AC motor.
Looking at your point from a different perspective, the 300RPM Hurst motor in current favor at VPI is audibly quieter and more speed stable than the old 600RPM Hurst motor. It's difficult to account for this if one takes the view that audible cogging effects are in an inverse relationship to motor speed.
BTW, the discontinued Kelley AC-1 controller allows separate control of each phase of a 2-phase synchronous motor, and probably does as good a job as any at reducing cogging.
|
Dgarretson,
Albeit the fact you are running a rather complex idler system on your drive chain, I still agree with Doug that you'll have audible cogging via the Mylar belt, especially with the 300 RPM motor. I've tried implementing the same Hurst motor (with the Kelly AC-1) in a "direct" pulley to platter setup on my Galibier, and have a hard time with the cogging artifacts, especially at 33RPM (the cogging is much less audible at 45 RPM). And yes, the Mylar belt will provide a much more direct link to the drive mechanism than string - too lossless for the Hurst AC motor. The Hurst motor in question simply has too much torque to allow for smooth rotation - so much so that I've been seeking alternative motors with less torque to try this experiment again - the Premotec/Philips-Airpax (as used in the Linn) with 4 mNm torque, and the Berger-Lahr as used in the Raven AC with 7 mNm of torque seem like better, low cogging alternatives to the Hurst with its beefy 19.06 mNm of torque. I now understand why VPI uses all those rubber belts, pulleys and flywheels - they are absolutely necessary to reduce the audible cogging of the Hurst motor. That said, I think there is some degree of virtue to be had with an AC synchronous motor - qualities that I am not (at this time) ready to remark upon fully, as more experimentation is needed. However, the Hurst is a fine 300RPM motor - very stable and with enough torque to overcome all but the mightiest amounts of stylus drag; I can see why VPI uses this motor. I'd also like to comment very positively on Mr. Kelly's controller - I wish I had one when I still owned my Linn; in many ways, it is far superior to the Lingo, if only for the fact that it can be tailored to the needs of every motor (of which no two are exactly alike). Good listening,
-Richard |
Yes Doug i am up and running and i must say that glitter backed mylar will pull my platter up to speed in two revolutions. I am hopping it stays that way a while.
Off of the subject i gave Atmos a run but after using UNIivers for over a year and a half i am going back with it. Atmos is one fine cartridge and if i had not heard UNIverse i would and could live with it but IMO UNIverse wins in all categories. Thanks to you an Paul again for the improved mylar tweak.
|
Doug,
I just received my first 'tweaked' belt. Significant improvement that was immediately noticeable. Thanks for sharing your experience. BTW, are you going to RMAF? |
Dgarretson,
Palasr's response, based on more experience than mine, confirms my speculation. Yes, the mylar (especially tweaked as per this thread) will provide far more grip than any thread.
***
Stltrains,
I won't say I'm surprised at your Atmos/UNIverse decision. I enjoyed the Atmos for rock, but for the music we listen to daily the UNIverse's superior resolution, speed and lack of overhang make most other cartridges nearly intolerable - even one as good as the Atmos.
Our system has improved in dynamics and bass response since we reviewed the Atmos. This makes the rock experience with the UNIverse very powerful. If we were reviewing today I'm not sure I'd need the Atmos's extra oomph, even for rock.
***
Jazdoc,
Glad to know another person has tried this tweak and is hearing the improvements.
Paul and I are both coming to RMAF (our first). I'm thinking of wearing a Hawaiian style grass skirt made of silver/holographic mylar, just so people can avoid me. What do you think?
|
Doug,
If you wear that you won't need an ID badge! I look forward to meeting you and Paul.
Regards,
Mark |
You guys have fun out there in Denver! Anne and I just can't seem to work out the RMAF dates with our schedules. |
If you wear that skirt, I'll wear my kilt. |
I finally got around to doing this over the weekend. For any that are looking to get etching cream Michael's has the Armour etching cream for $11.99 a bottle. They had a coupon in the paper for 40% off any item thus making it less than $7.00. Not bad for an audio upgrade. My results seem as others have mentioned with better dynamics and overall detail. Thanks Paul for coming up with this idea. |
UPDATE: our first AEB just reached the end of its useful life after 10-11 months of regular use.
The decline from fully dynamic to "what the heck's wrong" was quick and easy to diagnose. Over the last few days it didn't want to stay up on the capstan but kept riding down to the bottom flange. Re-levelling the motor helped some, but the physical belt wear was visible and there was little holographic sheen left. When I spun up a record it was obvious within moments that we had speed stability issues.
The AEB went from good performance to yuck in 4 days or less, which I guess is better than a slow decline that one might not notice. I spliced up a new one and all's right again.
Individual lifetimes will vary I'm sure, with the texture of the motor capstan being a factor. Ours is slightly rough, which may shorten belt life. As mentioned above, "helping" the platter to start and (for Teres owners) turning off the motor switch before stopping the platter should reduce belt/capstan slippage and lengthen belt life.
|
Hey Doug. My belt has needed more adjustment for flat speed lately, i guess its time for me to replace also. You mentioned your sheen is just about gone as is mine also. I am not having any problems with how the belt is riding though.
A question on the etching process. When i removed the backing i was not able to get all off. Does that sound about right to you.
Hoping your turkey was a good one
Mike |
Don't be too quick to replace the belt. It's a lot colder now, being winter, and thermal expansion will have an affect on your belt. I know that since I've been using a tape drive for the past 3 years this is exactly what happens when the temperature changes, the belt creeps up or down on the pulley and you have to re-tension it.
I machined a leveling base (has 3 adjustable leveling feet) for my motor pod to sit on and this makes it easy to dial in belt alignment and also helps isolate it. |
Regarding the cogging issues with the Hurst AC motors, the 300RPM motors have 24 poles, twice as many as the 600RPM motors so cogging is much more moticable with the 600RPM motors. I have at least 3 Hurst AC motors in the shop right now. I only use them as backups. |
Mike,
We had no trouble getting all the silver material off.
Frank,
My motor has three height adjustable spikes, so it's easy to adjust spindle angle like your base does (though I do wish my threads were a tighter fit). It would be difficult to use these belts without some such adjustment.
Thanks for the temperature tip, though in my case the belt was visibly worn and there's no question it needed replacement. I've been using mylar belts for 5 years and retensioning efforts were no longer working. Replacing it did.
With the acid etched mylar belt discussed on this thread, if there's little visible wear and if the holographic/rainbow effect is still visible, it probably doesn't need replacement yet, as you said. |
Thanks for the update, Doug. I've been wondering what I was going to do with that other 90-something feet of tape. ;-)
The tension thing is also different with the Galibier motor pod. With the extra girth and weight of the Galibier pod it is easy to over tension the belt. First you will begin to lose speed. I'm talking 5 to 10% drop. Make it a bit tighter and then the belt will practically jump right off the capstan.
Stltrains, I'm also puzzled why you had a problem getting the metal off. Maybe trying to be too frugal with the cream? |
Thanks Frank you are most likely right on with the temperature effect. Even down south in New Orleans winter has started early.
Doug as always your posts and info are very productive for good sound many thanks
Dan i was able to get most off with a fair amount of elbow grease, i guess i will have to put a little more effort into it.
all have a good one. |
Elbow grease. Really? Something doesn't seem right. I put the cream on with an artist's brush and the metal almost instantly disappears. No rubbing, scrubbing or anything. It just melts away in seconds. |
Dan the etching cream i bought is called Armour Etch. I only made one belt. It took me more that 15 minutes to remove the backing. Maybe my pick of cream is not as active as yours. I followed the directions I'm sure. Used a rag to apply the cream and let it sit a bit before wiping it off. |
Hi everyone,
I haven't been around this forum in a while -- been far too busy enjoying the Teres 160 I bought in late 2005. Well, I went back to the archives to search for mylar belt construction info., as my old belt (the one made by Teres) finally gave way at the splice -- about three years of regular listening later!
I did buy a few rolls of McCormick's holographic mylar some time ago in anticipation of this day, but don't think I ever ended up with any splice tape. In searching online now, I find the following options (some of these sources are listed in this thread):
1. VHS 1/2" splicing tape from tapecenter.com
2. TME professional / archival 1/2" splicing tape from usrecordingmedia
3. Pakor 1" premium splicing tape from pakor.com
4. 1 mil, 1" mylar silicone splicing tape from tapecase.com
Anyone have any opinions as to the best splice tape option for the mylar belt application?
I'll probably get into some acid-etching later, but for right now the immediate concern is getting supplies and making a belt ASAP so I can listen to some LPs! (And if anyone has an extra belt / feels like making an extra belt with their supplies on hand & sending it my way, this desperate analog fan would be happy to send a little $ for the favor...) |
Am dial you are so right in your musical hiatus. Just to get you by good old scotch tape will work till you get some splicing tape. Pull mylar around your platter and motor cut the excess at a angle and use scotch tape for the splice to get your analog play in while waiting.
I am sure more goners will chime in with more ideas. I have numerous made up belts dont know if they will work for your Teres though. |
Hi Am dial, long time no hear. Welcome back!
My long term suggestion is none of the above.
www.usrecordingmedia.com also has 1" TME professional/archival splicing tape. That's what I use, except mine's clear (frosted), not blue.
1) Cut the overlapped mylar ends on a 30-40 degree angle, not vertically, to avoid thumps when going round the motor capstan.
2) Lay the 1" tape across the splice at the same angle and burnish with a thumbnail.
3) Trim the excess off top and bottom.
Scotch tape is okay for emergency use but the splice will stretch, the adhesive will ooze and get all over your platter. Archival/VCR splicing tape won't do that. |
Am_dial,
Here is another splicing tape suggestion which has worked for me. Get a roll of 2" wide mailing tape, the kind used for taping cardboard boxes. These rolls come in both brown and clear, and while I have used both, the brown feels thinner for some reason. This kind of tape is very very thin, very very stong in tension, and the adhesive is very very sticky.
I have used mailing tape for all the mylar belts I have made over the last few years, and none have ever failed nor is there any evidence of stretching or adhesive ooze etc. The joints, when made as Doug advises above, do not thump and can not be heard unless your ear is right up against the belt. Best of all, this tape is readily available and inexpensive. |
I'm really at a loss Stltrains. I use Armour as well. It does say "improved" on the label. I'm assuming we bought the stuff around the same time. Go figure. ;-) |
Thanks Stltrains, Doug, and Zargon for all the good (and fast) advice. Before I even had a chance to read it, though, I made a temporary belt with some of the mylar and a piece of 2" Scotch brand packing tape as a splice. (So far it's working just fine & LPs sound as good as ever.) I then put in an order for Doug's preferred splice tape, so hopefully I won't have to use the temporary belt for very long...
Thanks too to Swampwalker for offering me a free belt!
I'll have to spend a little time in the archive and see what else I've missed all those nights I was spinning (or cleaning) LPs instead of checking this forum... |
Doug, I don't see the frosted colour splicing tape on the website you mentioned. |
Frank,
I didn't see it there either. I haven't seen clear or frosted A-V splicing tape in quite a while. My roll's 3-4 years old. |
Now I decided to take the mylar seriously and replace the thread belt on my VPI twin platters rim drive. As the plastic wheel is absolutely not adapted to drive mylar tape I will replace it with a Pinch roller wheel used on the capstan system of reel to reel tape decks, carefuly aligned and made by a specialist (terrysrubberrollers) in USA. I will keep you informed. |
I just want to stress importance of keeping your belt clean. I left it as-is for half a year because of my lazyness. Now I got it cleaned with alcohol: amaizing amount of dust deposit removed and I realized what I missed.
It seems all sonic goodies we have due to perfect grip of the etched mylar were gradually nullified by the accumulated layer of dust between belt and pulley. |
Absolutely true. I dust the working side of ours before every side by holding my CF brush against it. I also dust the platter rim before each listening session. Simple but essential.
The static potential buildup between belt and platter is a dust magnet and I once pondered grounding the belt in some way. Paul said, "Don't bother, the static's required to make the system work. The stronger the static buildup the better it's functioning.".
Naturally I didn't believe this harebrained nonsense, so I tried zapping the belt with a Zerostat while it was running. It instantly lost all grip with the platter. He laughed. I shrugged. After 26 years I'm used to making a fool of myself trying to test him on a science question.
At least I proved the Zerostat works. :-)
|
My dear Wife sat patiently one rainy afternoon to listen to her favorite music while I went through a similar cleaning maintenance routine as most here do.
I usually try to keep ahead by doing a thorough cleaning and dusting after use also.Usually.....
What she observed me doing lead to a short lecture asking me why I do not keep other things I use/own, especially my bathroom, to the same level of attention.
After 27 years together, now she really knows me....
On a different note.
Great informative subject and good work Doug and Paul.
|
I have tried the product Etch All etching creme.
The Etch All really did a great job or removing the metallic surface
within a few seconds, and supposedly does not use hydroflouric acid.
I did have to mark the front of the mylar before taking the silver off. Once the silver is off, I found it difficult to tell which was the front and which was the back. |
HI Emailist,
It is a slight difference to the touch. I find that the textured side will stick a bit when the mylar is allowed to freely slide on my finger. The smooth side just glides along. And, it is usually the side that the mylar wants to curl to. |
Emailist,
Just curious why you're messing around with mylar. Are you considering giving it a try on the Raven One? If so, be sure to post your findings. I'm curious about how the TWs proprietary belt material compares with a well implented tape drive. My guess would be that the TW belt is easier to install and more maintainance free at the cost of slightly lower performance but only someone who's compared directly could support or refute this hypothesis. |
Interesting indeed. At RMAF, TW's table was the only belt drive not using tape that didn't betray the obvious flaws of an elastic/rubbery belt. We walked out of a dozen other rooms within minutes, disappointed by softened transients and dulled microdynamics.
The Raven didn't do that, at least not that we could hear in that system, so TW's belt material must be unusually effective. Sonofjim's estimate seems right, but only a direct, in-system comparison will tell. Please do keep us posted.
|
DOUG D............
What is the reasoning in using 1 inch splicing tape
if the mylar is only half inch wide? are the splices precut to a predetermined length & that length is not
long enough for the splice? I'm a little confused.
I just ordered some Halographic 1/2 inch mylar & now
I need something to splice it, I am DONE with using
scotch tape as it contantly lets loose & leaves a sticky
residue on the cocobollo platter.
I also plan to order some etching creme to remove the
metallic from the mylar. |
