A simple mod for the later H-K turntables

[marcmorin]

Making this as simple as possible, obtain a plastic 35mm film can and fill it ca 1/2-3/4 full with clean dry dust-free sand, aquarium sand would be good. Set it centered atop the ITO gimbal tongue (you do remove the dust cover to play your H-K, right?) and spin a few of your fave well-known albums and get back to me.

Hi Pio, just a simple question. I understand this solution is a drain for energy.
If you could make sure your device is sealed, what do you think of using 10,000CST instead of sand? I would think the silicone oil would cover a much wider frequency spectrum.

 

[Pio1980]

Silicone isn't right for this app, we need something that is really self-lossy and self-adaptable to almost any frequency, the silicone will just act as a solid under these cdx in this app. The sand also acts as a very dead mass to load the upper part of the arm structure without creating another resonant structure that the lower damper can't handle, it's good for the DIYer as a readily available commodity that suits the purpose. All in all these simple mods are pretty much an integrated solution to the TT's major shortcomings.

 

[Gravelyguy]

Pio,

I will try this out and get back to you. The more albums I listen to the more amazed I am at what I am hearing. There are times when it feels like I could walk around the instruments being played.

Dave

 

[Pio1980]

Hi Pio, just a simple question. I understand this solution is a drain for energy.
If you could make sure your device is sealed, what do you think of using 10,000CST instead of sand? I would think the silicone oil would cover a much wider frequency spectrum.

Hi Marc;
For silicone to work as damping it needs a containment application that would work a moving object against a relatively stationary mass thru the viscous medium, a particle filled capsule can do this self-standing as long as the vibrations of interest are high enuff to break up some-to-all of the mass of particles and cause them to temporary float, rubbing against one another and the containment wall surfaces and thus quickly dissipating the energy as heat, forming an untuned sink where the energy is readily absorbed. Bill Firebaugh does this in his sand-filled Well Tempered Arm pipes and before that Warfdale in their sand-walled loudspeakers, still a brilliant approach IMO. As I said previously, the hollow arm straw of my Souther is now bead-filled, it's easy to see how effective this should be in that particular application from studying the design and compromise/shortcomings of the Souther arm system.
I use glass beads for dental practice endodontic instrument sterilizers, the glass beads in eyeglass templepeice warmers would also work if fine enuff. Another source is the reflectorizer beads used in highway marking paint. The optimal grade and quantity would have to be determined in laboratory experimentation tho' reasonable guess-timate application works well enuff for all practical purposes.

 

[Pio1980]

For perspective, the other in-use TT at present in the experimental system and the 'standard' is the only TT I have encountered that has needed nearly nothing to work to it's full potential as-is, a Mitsubishi LT-30, a formidable standard even with an entry-level Denon DL-110 HOMC. If I could only have one TT this would be it but the H-K would be about the last to go before it. They should and do sound different, the H-K does musicality and perspective very well, the Mitz is exceptionally clean and precise without being analytical and very satisfyingly 'musical' in all the right ways. Both have dead-silent background noise floors.
The Big Mitz has nearly 3 lbs of mass loading in the arm/base carriage structure on a very tightly spec' ed gimbal/arm assembly, the platter is quite dead and it's motor/servo drive is sonically faultless. They got almost everything nearly right in a relative affordable and musically satisfying package, it just appeals to me as a physically esthetically clean and elegantly excecuted servo LT integrated. On that basis alone I'd rather have this than any of the more exotic vintage integrated LTs (Goldmund, Yamaha, ect). The fact that it sounds as good as it works is gratifying.

 

[marcmorin]

Hi Marc;
For silicone to work as damping it needs a containment application that would work a moving object against a relatively stationary mass thru the viscous medium, a particle filled capsule can do this self-standing as long as the vibrations of interest are high enuff to break up some-to-all of the mass of particles and cause them to temporary float, rubbing against one another and the containment wall surfaces and thus quickly dissipating the energy as heat, forming an untuned sink where the energy is readily absorbed. Bill Firebaugh does this in his sand-filled Well Tempered Arm pipes and before that Warfdale in their sand-walled loudspeakers, still a brilliant approach IMO. As I said previously, the hollow arm straw of my Souther is now bead-filled, it's easy to see how effective this should be in that particular application from studying the design and compromise/shortcomings of the Souther arm system.
I use glass beads for dental practice endodontic instrument sterilizers, the glass beads in eyeglass templepeice warmers would also work if fine enuff. Another source is the reflectorizer beads used in highway marking paint. The optimal grade and quantity would have to be determined in laboratory experimentation tho' reasonable guess-timate application works well enuff for all practical purposes.

All good stuff my friend. As soon as I can get an email working I'll send a link to vibration modes and analysis. Also, I would like to see how you're employing this. My minds-eye I think, is "seeing" this from your description different than your application.

 

[Pio1980]

I'll get pix up of the 2 type damping capsules and their application on the H-K/ITO arm ASAP.

 

[Pio1980]

"I'll get pix up of the 2 type damping capsules and their application on the H-K/ITO arm ASAP. "
The arm, the gutted disposable lighter damping capsule and proper positioning, the Buss fuse box sand tray damper, adhesive, and proper positioning (note that is off-center at the free end of the 'L' piece. Check to see if the dampers clear the closed dust cover. The lighter capsule may be used unbonded dismountable if necessary without adhesive with the roughened label-removed side down tho' bonded is best, the yellow sandbox damper must be attached to work properly.
Use only a water soluble stick glue as an adhesive, not superglue, epoxy, double-sticky foam tape, ect to attach dampers. It has to transfer vibration and be reversible for removal and cleanup if/when desired.

 

[wlmill]

For perspective, the other in-use TT at present in the experimental system and the 'standard' is the only TT I have encountered that has needed nearly nothing to work to it's full potential as-is, a Mitsubishi LT-30, a formidable standard even with an entry-level Denon DL-110 HOMC. If I could only have one TT this would be it but the H-K would be about the last to go before it. They should and do sound different, the H-K does musicality and perspective very well, the Mitz is exceptionally clean and precise without being analytical and very satisfyingly 'musical' in all the right ways. Both have dead-silent background noise floors.
The Big Mitz has nearly 3 lbs of mass loading in the arm/base carriage structure on a very tightly spec' ed gimbal/arm assembly, the platter is quite dead and it's motor/servo drive is sonically faultless. They got almost everything nearly right in a relative affordable and musically satisfying package, it just appeals to me as a physically esthetically clean and elegantly excecuted servo LT integrated. On that basis alone I'd rather have this than any of the more exotic vintage integrated LTs (Goldmund, Yamaha, ect). The fact that it sounds as good as it works is gratifying.

I haven't made a lot of comments in this thread, because I don't understand a lot about modding a turntable. I have learned a lot from reading about your mods. It has been interesting to read your comparison of the Mitz and the H-K. It has always been amazing to me, how each turntable can sound different. If I have an opportunity to pick up a Mitz or an H-k, I will. This thread will be very helpful to me if I ever get an H-K turntable.

Thank you

 

[rnorton]

The arm, the gutted disposable lighter damping capsule and proper positioning, the Buss fuse box sand tray damper, adhesive, and proper positioning (note that is off-center to the free end of the 'L' piece. Check to see if the dampers clear the closed dust cover. The lighter capsule may be used unbonded dismountable if necessary without adhesive with the roughened label-removed side down tho' bonded is best, the yellow sandbox damper must be attached to work properly.
Use only a water soluble stick glue as an adhesive, not superglue, epoxy, double-sticky foam tape, ect to attach dampers. It has to transfer vibration and be reversible for removal and cleanup if and when desired.

Do you think this mod would also be useful on an 'unsuspended' T-25? The arm is a somewhat higher mass one than the one used in the higher numbered models. I've already applied Frank Van Alstine's suggestion about heavy silicone on the gimbal bearings.

 

[Pio1980]

Do you think this mod would also be useful on an 'unsuspended' T-25? The arm is a somewhat higher mass one than the one used in the higher numbered models. I've already applied Frank Van Alstine's suggestion about heavy silicone on the gimbal bearings.

Looking at your TT I don't see an application for it with this mod, Frank seems to have it covered nicely.
The T-25 has a different arm/pivot gimbal from the others which use the ITO Micro Race arms including the T-20, all of which could benefit from the sandbox damper. There is no perch for the damper on the T-25 arm gimbal and it probably wouldn't benefit from it regardless being a different structure.

Good listening!

 

[Gravelyguy]

Pio,

I tried the film canister and was very impressed with the early results. I will do more listening when I get the chance. I checked out your pictures. What size fuse box did you use? The one I have holds much less sand than the canister.

Dave

 

[Pio1980]

Re the fuse box, it's the standard hard clear plastic tray/sliding metal top type. Use only this type as the frosty all-plastic ones won't seal securely. Give it a try as described vs the canister and let us know your results.

 

[rnorton]

Looking at your TT I don't see an application for it with this mod, Frank seems to have it covered nicely.
The T-25 has a different arm/pivot gimbal from the others which use the ITO Micro Race arms including the T-20, all of which could benefit from the sandbox damper. There is no perch for the damper on the T-25 arm gimbal and it probably wouldn't benefit from it regardless being a different structure.

Good listening!

Yeah, I noticed that the top of the gimbal isn't flat but rather slightly roofed, which would make mounting difficult unless I used two smaller containers.

I may try anyway, just to see (or hear).

Frank never mentioned how often the silicone would need to be replaced on those bearings. Do you think washing them out annually with lighter fluid and re-applying would be a good idea? I'm in a very dusty environment and exposed silicone seems likely to pick up grit over time.

 

[Pio1980]

Yeah, I noticed that the top of the gimbal isn't flat but rather slightly roofed, which would make mounting difficult unless I used two smaller containers.

I may try anyway, just to see (or hear).

Frank never mentioned how often the silicone would need to be replaced on those bearings. Do you think washing them out annually with lighter fluid and re-applying would be a good idea? I'm in a very dusty environment and exposed silicone seems likely to pick up grit over time.

First this type damper requires a hard buzz-free contact with the item to be damped. Second this gimbal will require a saddle-type hard mount as the parasitic vibration modes with be mostly lateral & fore-aft, the ITO has them in every possible axis. Perhaps taking a mold of it for an acrylic cast mounting platform as close to the gimbal top as possible is probably the way to go. You could leave a hole if desired for the needle bearing adjustment.

Your concerns about the silicone doped bearings mirror mine, I've thus been hesitant to try it on any of my arms. Solvent cleaning may be as likely to flush debris in as out, proceed with caution. If the silicone is fairly stable I'd leave it be until problems occur indicating fouled/ deteriorated compound.

 

[Pio1980]

All good stuff my friend. As soon as I can get an email working I'll send a link to vibration modes and analysis. Also, I would like to see how you're employing this. My minds-eye I think, is "seeing" this from your description different than your application.

I'd be very interested in seeing what you have, thnx Marc!!

 

[Pio1980]

I made some time to listen to the H-K with the arm damper this evening and would like to comment but will withhold as I'd really like to hear from other H-K/ITO users on their impressions of either version of the damper or even just the partially filled canister, please? A fully mod'ed TT would be best for both of us.
As some of you already know, I am somewhat hearing impaired and working alone in isolation here without contact with other 'philes, so I really could use some correlational feedback from others that get out more than I do.

 

[Gravelyguy]

Hi Pio,

Busy weekend so I have not had a chance to post my thoughts until now. I tried both the canister and the glued fuse holder tone arm mods. I'll be honest, I logged much more time with the fuse box. Once I put it on I didn't really want to start the glueing ungluing. I just wanted to listen.

I don't know that I have the greatest hearing either, but what I did hear was a lot of nothing. Everything got so much quieter. The lead in and run outs, the space between songs, and of course the quiet passages. It really helped the notes extend and made, particularly the live music we listened to just pop out and sound, well live. Like I believe you observed earlier, this tt does live small groups well. I listened to quite a bit of Brubeck and it was stellar. But this also did RLJ and live Bruce Springsteen very, very well too.

So once again, thanks Pio for helping us tt knuckle draggers get the most out of the t60. I am so glad I kept this tt. It was a toss up between this and an SL 1700. It is not even close now. I did mod your mod and put black electrical tape on the top of the fuses box to help it blend in better. It looks pretty good.

Dave

 

[Pio1980]

Very good, thnx.
I must admit to being so astonished with the initial results with the arm damper that it's difficult to maintain objectivity, this is why I withheld comment.

What I heard (with the disposable lighter damper) was much more than an improvement in detailing and dynamics, there was an over-all transformation of the source playback into a significantly higher class of result. It did not sound like the same arm or cartridge, rather something much more costly and much higher grade. Still the same Digitrac cart and ITO arm, I had no idea the Digi was this good, it's somewhat "technical" analytical fussiness has disappeared with the result becoming something like I'd hope to hear from, say, a good moving coil cart I could actually afford. The ITO arm has it's virtues but the wide-span side-hanger gimbal is inherently a problematical resonance festival in dire need of attention and I've put long-term contemplation into this fix as with the substructure plate damper. I will continue to think on the project but I think we are here at the end-point toward rapidly diminishing returns considering the simplicity and economy of effort.
I believe this regimen of 3 simple remedial procedures transforms a cheap and cheerful alternative to other budget vintage TTs into a seriously competitive true Audiophile grade vinyl program source. Sometimes one gets lucky and gets it right and we all benefit, this is now no doubt sonically my best TT.

 

[marcmorin]

Very good, thnx.
I believe this regimen of 3 simple remedial procedures transforms a cheap and cheerful alternative to other budget vintage TTs into a seriously competitive true Audiophile grade vinyl program source. Sometimes one gets lucky and gets it right and we all benefit, this is now no doubt sonically my best TT.

Can't wait to hear your impressions of it after you strap a nice Grado Signature on it. Coming soon. :thmbsp: