VPI HW-19 motor isolation

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mdelrossi

  • Jr. Member
  • Posts: 17
VPI HW-19 motor isolation
« on: 11 Feb 2016, 02:56 pm »
Hello,
I have a old (80's) VPI HW-19 mk3 with the original 600rpm motor, attached to the plinth.

I've tried sorbothane, 3M VBH tape(works the best) to tame the vibrations from the motor.

I was wondering if there was anything from herbs that would help.

thanks
mdr

Herbie

Re: VPI HW-19 motor isolation
« Reply #1 on: 11 Feb 2016, 03:37 pm »
Between the motor and plinth where the motor mounts, regular (1.6mm-thick) grungebuster material is superb, either as Dots, Washers, or sheet material cut to gasket shape. Externally around the motor and mount, rope caulk (available at hardware stores) is an excellent, sonically neutral microvibration-absorbing material, as is Permatex Blue RTV Silicone Gasket Maker (available at auto parts stores and some hardware stores). Applied strategically, these materials can be quite beneficial in and around plinth parameters.

Steve Herbelin
Herbie's Audio Lab

Markd51

  • Jr. Member
  • Posts: 46
Re: VPI HW-19 motor isolation
« Reply #2 on: 11 Feb 2016, 04:09 pm »
One I know had used your Iso Cups and Balls as replacements for the stock VPI Sorbothane Puck Suspension with very favorable results.

I myself used your tall Tenderfeet, and also inserted a 44mm Grungebuster Disc within each routed Puck Depression in the Wooden Base.  Although I had both regular density, and firm density Tenderfeet, I chose the firm, considering the amount of weight with a custom arrangement of a solid 1" Black Acrylic Plinth, a 10lb VPI Steel Sub Chassis bonded to the Plinth underside, and a 16lb VPI MK-IV Platter.

I did hear an immediate difference in better neutrality, better detail, and an even lower noise floor.

I of course use the VPI Sama with my set-up, and the wimpy stock rubber feet that comes on the SAMA were proving problematic with the SAMA not staying firmly positioned in place under the Table,

Again, your standard height Tenderfeet came to the rescue, replacing the VPI rubber SAMA Feet, and now the SAMA does not budge at all.  Like it is glued in place, rock solid.

Small Grungebuster Washers were placed in between the Hurst AC Motor Face Flange, and the SAMA Enclosure-Housing, which hold the Hurst AC Motor within, and also used the same size small Grungebuster Washers in between the stock VPI Motor Pulley Cover, and the 3 Standoffs that hold it.

My 4 Audiopoint Feet that were replacements for the Stock rubber feet on the Wood Base also sit upon your Brass Coupling Discs with DBNeuralizer Material Pads, and even the Spike Feet of my SRA Iso Base 3.0 that the Entire Table and SAMA rests upon sit again on the same Coupling Discs with DBNeuralizer Pads

For the pittance of what these goodies cost, they sure did take my table from an already good level of performance to a much better level which I feel could never have been realized without the use of these tweaks.

Markd51

  • Jr. Member
  • Posts: 46
Re: VPI HW-19 motor isolation
« Reply #3 on: 11 Feb 2016, 04:22 pm »
Oh, almost forgot, my stock VPI Platter Spindle Washer was also replaced with the Grungebuster Model

Markd51

  • Jr. Member
  • Posts: 46
Re: VPI HW-19 motor isolation
« Reply #4 on: 11 Feb 2016, 04:33 pm »
With a stock VPI HW-19 set-up (No SAMA), I imagine that Motor Noise and vibration could possibly be transferred from the Drive Belt to the Platter, but that amount would probably be quite small.

That that majority of Noise and Vibration would be passing and being transferred from the Wooden Base that the Motor is attached to, up through the Plinth to the Platter, and to the Tonearm Base.

As you know, VPI used a few different methods of  Suspenion isolation and physical separation from these two components, being the Wooden Base, and the Plinth that resides and rests within.

Those were the Suspension Springs, Sorbothane Pucks, and a newer Suspension Type that they probably still currently sell.

The Standard Firmness Tall Tenderfeet would be a simple and effective suspension component replacement for the Pucks or Springs.  The Firm Model would probably not be needed unless you are using quite heavy platters, and such like I mention above in my previous post.

As for better Motor Isolation from the Wooden Base, a slew of Grungebuster Washers placed between both Motor and Motor Bracket, and Motor Bracket and Wood Base should prove effective.

GentleBender

Re: VPI HW-19 motor isolation
« Reply #5 on: 11 Feb 2016, 05:53 pm »
One I know had used your Iso Cups and Balls as replacements for the stock VPI Sorbothane Puck Suspension with very favorable results.

I myself used your tall Tenderfeet, and also inserted a 44mm Grungebuster Disc within each routed Puck Depression in the Wooden Base.  Although I had both regular density, and firm density Tenderfeet, I chose the firm, considering the amount of weight with a custom arrangement of a solid 1" Black Acrylic Plinth, a 10lb VPI Steel Sub Chassis bonded to the Plinth underside, and a 16lb VPI MK-IV Platter.

I did hear an immediate difference in better neutrality, better detail, and an even lower noise floor.

I of course use the VPI Sama with my set-up, and the wimpy stock rubber feet that comes on the SAMA were proving problematic with the SAMA not staying firmly positioned in place under the Table,

Again, your standard height Tenderfeet came to the rescue, replacing the VPI rubber SAMA Feet, and now the SAMA does not budge at all.  Like it is glued in place, rock solid.

Small Grungebuster Washers were placed in between the Hurst AC Motor Face Flange, and the SAMA Enclosure-Housing, which hold the Hurst AC Motor within, and also used the same size small Grungebuster Washers in between the stock VPI Motor Pulley Cover, and the 3 Standoffs that hold it.

My 4 Audiopoint Feet that were replacements for the Stock rubber feet on the Wood Base also sit upon your Brass Coupling Discs with DBNeuralizer Material Pads, and even the Spike Feet of my SRA Iso Base 3.0 that the Entire Table and SAMA rests upon sit again on the same Coupling Discs with DBNeuralizer Pads

For the pittance of what these goodies cost, they sure did take my table from an already good level of performance to a much better level which I feel could never have been realized without the use of these tweaks.
Markd51,

Any idea of what size washers for between the motor, bracket, and wood base. This is exactly what I need to do! Plus the Tall Tenderfeet.

Thanks,
Jason

GentleBender

Re: VPI HW-19 motor isolation
« Reply #6 on: 13 Feb 2016, 05:46 pm »
Anybody out there to give me some advice on what size washers? Otherwise I will have to take everything apart and then go through the hassle of setting the table up from scratch.  :cry:

Markd51

  • Jr. Member
  • Posts: 46
Re: VPI HW-19 motor isolation
« Reply #7 on: 16 Feb 2016, 06:48 pm »
Sorry for not responding sooner.  I believe the small grungebuster washers I ordered a slew of were 6mm O.D.

I seem to remember that Steve Herbelin also makes available, grungebuster sheets, that can be had either with a peel and stick adhesive backing, or without.

While maybe not as "pretty" as what Steve can provide, in most areas of a HW-19 Table that you would be adding this material to, would never be seen anyway once the table is re-assembled. Probably one small sheet of standard 1/16" thickness grungebuster material would be sufficient to tweak all pertinent areas on the HW-19.

A dial caliper, and small metal ruler sure came in handy for me when I ordered all my goods from Steve the one time, and it sure paid off, knowing that the Tall Tenderfeet and a standard thickness 44mm Grungebuster Dot were the perfect height replacement for my stock Sorbothane Suspension Pucks  (My HW-19 started life as a Junior Model which I bought new in 1996)

With one small single grungebuster sheet, one could then custom cut pieces to apply in areas like between Motor Bracket, and Wood Base, or elsewhere to good effect. 

An increase in motor noise can also be caused by other things on a VPI HW-19 Table and the Hurst AC Syncho Motor.  These Motors do need lubrication once in a blue moon, that a small drop of either 30W or 40W Motor Oil be applied to where the Motor Drive Shaft enters into the Motor itself.  This area is of course beneath the Drive Pulley on the Motor.  Something like a small Pipette would aid the proper placement of Oil to the Drive Shaft where it enters the Motor Housing.

Other areas of possible noise is the Platter Bearing. The Bearing Surfaces should be inspected from time to time to insure the Tungsten Carbide Thrust Pad is not worn, the Bearing Ball at the bottom of the Bearing Shaft is not galled or has any flat spots, and that the upper Bearing Bushing Surfaces and Bearing Shaft have a thin film of good Oil applied. 

One can simply use Mobil 1 Synthetic 5-30W in all areas I mention as a lubricant.  An ounce in a small bottle will last many years, the rest can be thrown in a vehicle's engine.

Can a Hurst AC Drive Motor eventually go bad over a long period of time, and become more noisy?  I'm sure it can.  As far as I know, where the Drive Shaft enters the Motor, it is only just a Brass or Bronze Bushing.

A cheap Stethescope is a good tool to have on hand to pinpoint and source areas of noise and what types of noises they are.

GentleBender

Re: VPI HW-19 motor isolation
« Reply #8 on: 16 Feb 2016, 09:17 pm »
Thanks for replying Markd51. Just figured I would save myself some work and copy your homework. :D I will make sure to throw a sheet of 1/16" grungebuster in with the order. My HW-19 still has the stock springs which I will be replacing as well.

sturgus

Re: VPI HW-19 motor isolation
« Reply #9 on: 18 Feb 2016, 01:56 am »
Don't forget the motor mounts, if yours are the originals. You can still get these from VPI, $24 for a set.  This will also help a lot.

tlainhart

  • Jr. Member
  • Posts: 10
Re: VPI HW-19 motor isolation
« Reply #10 on: 6 Mar 2016, 03:40 pm »
Late to the party here, but I went the same route as you before buying a SAMA (they're NOS at MusicDirect at the moment).  I own an HW-19 Mk3 with "4" upgrades.

  • Purchased NOS motor mount bushings from Harry Weisfeld at hw "@" hwsworkshop.com
  • Purchased grungebuster washers from Steve to place between the motor mount cage and wood plinth: 6 x  3/4" OD, 1/8" ID)
  • Purchased grungebuster washers to place between the arm board and plinth: 6 x  1" OD, 1/4" ID
  • Purchased a grungebuster washer to place between the motor housing, and the cage that it screws to: 1 x 2.75 OD , 1 1/8 ID

I used a light misting of a Locktite spray adhesive (used for picture mounting, etc.) to the backs of these washers to keep them in place.

Ultimately, it didn't seem to make a big difference in terms of reducing the vibration transferred to the plinth.  My next upgrade (which I haven't yet ordered) is to get some tall, firm tenderfeet to replace the VPI sorbothane plinth isolators.

Good luck.

Steve also says that a mat helps in this application.

GentleBender

Re: VPI HW-19 motor isolation
« Reply #11 on: 7 Mar 2016, 09:39 pm »
Sturgis,

Thanks for the heads up.

GentleBender

Re: VPI HW-19 motor isolation
« Reply #12 on: 7 Mar 2016, 09:40 pm »
tlainhart,

Thanks for the detailed information and your end result. I've got a couple things going on and plan to return to this. I'm going to wait until I have everything before moving forward, even though there are many things worse than setting up a turntable, I would rather do it all at once. Thanks again! Plan and patience for the win...

Markd51

  • Jr. Member
  • Posts: 46
Re: VPI HW-19 motor isolation
« Reply #13 on: 13 Mar 2016, 06:55 pm »
Setting up a HW19 is not too bad. About the hardest things are the use of the SAMA where it stays put, and of course doesn't touch the Wood Base.  As I mentioned earlier, I found 4 of the regular height and regular softness Tenderfeet to be a perfect replacement to set the SAMA upon. The Stock Rubber Feet simply unscrew.

Still, I suppose vibration can pass from SAMA to Turntable Base-etc, because all still might sit on the same Shelf-Stand.

I have seen some make something like A Sand Base-Box, where the SAMA would rest on an isolated portion of the Top Plate of the Sand Base-Box, further isolating it from the rest of the Table.

And about the only one other thing that could be a pain to get just right, was the older VPI Black MK-IV/TNT Platters that had the "3-Point suspension system" that were adjustable, and was extremely easy to get a Platter out of whack with excessive up-down travel/motion.

I had this problem, as I bought my Mk-IV Platter used, and the previous owner retracted all the screws as he no doubt had these issues.

I bought a Dial Indicator, and a Vacuum Base-Stand for it, and was able to accurately zero the Platter.  That because before, that up and down motion of the platter and the record could be heard.

To insure I never again lose that precise setting which I had gotten down to +/- .003" play, and for any periodic future Bearing Lubrication, I now always clamp the Platter to the Bearing Shaft with the Spindle Clamp, and pull the entire Platter with the Shaft screwed-secured to it, clean Bearing Well and Shaft, re-install, and I'm good!

As I close, I do believe that these Hurst AC Motors weren't exactly the finest precision Motors made on the planet, and I'd no doubt be correct that there can be a variance of noise, and performance from them.  And that too, I'd imagine they do have a life, meaning at some point in time they will not perform as well as new.

mjalazard

  • Jr. Member
  • Posts: 38
Re: VPI HW-19 motor isolation
« Reply #14 on: 27 Jan 2017, 01:06 am »
I have had great success with a  homemade isolation stand: Two pieces of a large marble cutting board (Ikea purchase over 20 years ago).  I popped off the rubber feet and sandwiched a sorbothane  mat in between.  This can be then set upon 4 isolation feet of your choice (tender feet).  Place your turntable set up on that with isolation feet on the 'table as well.  It is inexpensive and very heavy.  My turntable rode through and aftershock of the Northridge earthquake 23 years ago without missing a beat.
Mike