Pio1980
AK Member
Thnx!!! I was going to put it on the Mitz LT-30 but this last development may be a game-changer.
Ready to try a sandbox tray damper on an XA?
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A simple mod for the later H-K turntables
- Thread starter Pio1980
- Start date
Thnx!!! I was going to put it on the Mitz LT-30 but this last development may be a game-changer.
Ready to try a sandbox tray damper on an XA?
The only modification done to my T-60 so far is the external power supply. I'll have to catch up on some of the ideas here, the table already hits far above its weight class. It usually runs with a V15III or ADC QLM.
Gravelyguy
Active Member
Sam,
It is well worth the few minutes and pennies to do Pio's mods to your unit. It is truly amazing the performance my t60 has. I listened to Frampton Comes Alive last night and had a hard time believing that I was listening to the same album that I have had for decades.
I have not done the power supply mod yet so am curious what your thoughts are after doing Pio's mods and the power supply.
Dave
It is well worth the few minutes and pennies to do Pio's mods to your unit. It is truly amazing the performance my t60 has. I listened to Frampton Comes Alive last night and had a hard time believing that I was listening to the same album that I have had for decades.
I have not done the power supply mod yet so am curious what your thoughts are after doing Pio's mods and the power supply.
Dave
I'll definitely look into continuing the upgrade path on mine. The external power supply quieted mine down a lot - having the transformer mounted to the same metal plate as the tonearm base was a bad idea. By the end of an album, it would always have a weird mid-pitched hum going on. With the transformer outside in another box, the noise is gone. The good news is that Rat Shack still has just about everything from the original Van Alstine article, most with the same part numbers. About the only places I changed it were the plastic project box and lighted switch.
Mawerick
Well-Known Member
I'm not planning on doing the outboard power mod for now. Instead, I tried something else. I unscrewed the metal plate holding the motor and transformer, and stuck some double-sided foam tape between it and the plinth. Then I tightened the screws just enough not to compress the tape.
It sort of works, background is somewhat darker now. I guess it does isolate the micro vibrations coming from the transformer to a degree.
It sort of works, background is somewhat darker now. I guess it does isolate the micro vibrations coming from the transformer to a degree.
Pio1980
AK Member
From another thread posting;
I passed on a nice AR TT on the 'bay to examine 'cuz I had the H-K project in hand and no spare change, haven't seen the innards of them personally tho' the H-K is likely more rigid and the Linn KEEL the benchmark of rigidity. It's relative. The H-K's 'rigid' sub-plate should ring like the frying pan it resembles without damping and it's other mid-bass resonance from the "tuning fork" formed between the counterbalance and arm off the platter's mass is a solvable problem as well that I addressed with the counterbalance floating dead mass load damping remount, no significant added mass to alter suspension parameters. The arm gimbal is basically a nice broad bearing barrel end-mounted in a tuning fork that literally screams for damping, easily applied with dead mass load damping. This also damps the arm resonances as well as terminating the upper end of the pillar with dead mass damping. Again, elegant.
The interesting thing about the simple mods to the H-K is that the design provides for them almost as if they just decided not to finish the job right for unknown reasons.
The point of this posting;
You can pretty much play around thumping things on the TT and model the thing in your head and fool with it to find resonant structures ("tuning forks") and model ways of dealing with them. This is the method I use and it works most of the time. A stethoscope on the arm gimbal and base can show re-activeness of the cart/ arm/pillar/mounting. This is one area where achieving a non-peaky low-level result is very important IMO and the major reason for sonic differences between arms. Dead-mass load damping of the gimbal/pillar could pay huge dividends here toward neutralizing the sound but almost no-one does it. I'm also of the school that a cart needs inherent reactive-resistant mass loading to direct the energy into the transducer and not down the arm and pillar into the baseplate and delayed back to the cart. Heavier is better regardless of compliance for lifelike transient response IMO. Grounding the record solidly to a semi-resilient or hard mat with a heavy-ish damped platter serves the same purpose, I do not care for the idea of mat arrangements that 'float' the disc unsupported by hard backing, rendering them both microphonic and reactive which while perhaps euphonic definitely not neutral. H-K got that right better than most with their slightly dished hard mat/weight arrangement.
EDIT: Life is full of suprizes to the open-minded observer, see the "Meitner mod" in a later posting for the latest mod ehancement.
__________________
I passed on a nice AR TT on the 'bay to examine 'cuz I had the H-K project in hand and no spare change, haven't seen the innards of them personally tho' the H-K is likely more rigid and the Linn KEEL the benchmark of rigidity. It's relative. The H-K's 'rigid' sub-plate should ring like the frying pan it resembles without damping and it's other mid-bass resonance from the "tuning fork" formed between the counterbalance and arm off the platter's mass is a solvable problem as well that I addressed with the counterbalance floating dead mass load damping remount, no significant added mass to alter suspension parameters. The arm gimbal is basically a nice broad bearing barrel end-mounted in a tuning fork that literally screams for damping, easily applied with dead mass load damping. This also damps the arm resonances as well as terminating the upper end of the pillar with dead mass damping. Again, elegant.
The interesting thing about the simple mods to the H-K is that the design provides for them almost as if they just decided not to finish the job right for unknown reasons.
The point of this posting;
You can pretty much play around thumping things on the TT and model the thing in your head and fool with it to find resonant structures ("tuning forks") and model ways of dealing with them. This is the method I use and it works most of the time. A stethoscope on the arm gimbal and base can show re-activeness of the cart/ arm/pillar/mounting. This is one area where achieving a non-peaky low-level result is very important IMO and the major reason for sonic differences between arms. Dead-mass load damping of the gimbal/pillar could pay huge dividends here toward neutralizing the sound but almost no-one does it. I'm also of the school that a cart needs inherent reactive-resistant mass loading to direct the energy into the transducer and not down the arm and pillar into the baseplate and delayed back to the cart. Heavier is better regardless of compliance for lifelike transient response IMO. Grounding the record solidly to a semi-resilient or hard mat with a heavy-ish damped platter serves the same purpose, I do not care for the idea of mat arrangements that 'float' the disc unsupported by hard backing, rendering them both microphonic and reactive which while perhaps euphonic definitely not neutral. H-K got that right better than most with their slightly dished hard mat/weight arrangement.
EDIT: Life is full of suprizes to the open-minded observer, see the "Meitner mod" in a later posting for the latest mod ehancement.
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muzy
Active Member
afer reading and rereading, I thought I would try the glass of water to look for vibrations. could find none on my 35c. I don't know?
Did take the dust cover off and it seemed to open up the sound stage, I like it thanks.
PIO1890 I was not able to gleen from this thread what cart are you using? glen
Did take the dust cover off and it seemed to open up the sound stage, I like it thanks.
PIO1890 I was not able to gleen from this thread what cart are you using? glen
Pio1980
AK Member
I'm using one of the Ortofon DigiTrac 200 NE 'tombstone' tipped carts that sold on e-bay for $20.
These mods are for the suspended TTs and those using the ITO arm. A water pool will only show motor drive and externally introduced vibration, my mods mainly deal with acoustical resonance management in the TT & arm structures.
These mods are for the suspended TTs and those using the ITO arm. A water pool will only show motor drive and externally introduced vibration, my mods mainly deal with acoustical resonance management in the TT & arm structures.
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Today I got around to doing this mod, as well as some other maintenance, and I must say it's made an audible improvement in my T-55C. The bass seems firmer and overall clarity is a touch better.
The spindle has an oil port in the side:
I cleaned all the old oil out and added fresh 20w:
Mine came with fabric wrapped around the springs, so I left them alone:
It also came with some foam on the bottom tray, so I left that as-is as well:
I also changed to the 25.75" belt, which is a nice, loose fit. I had already done the Van Alstine PS mod, so this thing is pretty much done. I'm on the fence about gluing a sandbox on top of the Ito tonearm, for purely cosmetic reasons.
Thanks for posting this thread Steve! :thmbsp:
The spindle has an oil port in the side:
I cleaned all the old oil out and added fresh 20w:
Mine came with fabric wrapped around the springs, so I left them alone:
It also came with some foam on the bottom tray, so I left that as-is as well:
I also changed to the 25.75" belt, which is a nice, loose fit. I had already done the Van Alstine PS mod, so this thing is pretty much done. I'm on the fence about gluing a sandbox on top of the Ito tonearm, for purely cosmetic reasons.
Thanks for posting this thread Steve! :thmbsp:
Pio1980
AK Member
Hi Mark! You will be glad you did the sandbox when you hear what it does to neutralize the arm/gimbal resonances, trust me on this as with the other mods.
Lovely job BTW, it'll definitely pay you back with better long-term performance.
I haven't tried Dynamat or sim in the belly pan but it couldn't hurt. I did stick a tire balance weight to a double-sticky foam strip in the middle to handle the LF resonances
Lovely job BTW, it'll definitely pay you back with better long-term performance.
I haven't tried Dynamat or sim in the belly pan but it couldn't hurt. I did stick a tire balance weight to a double-sticky foam strip in the middle to handle the LF resonances
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Pio1980
AK Member
Here we go again---
There is a further enhancement for the fully-mod'ed H-K and this one beggars logic but actually works, it comes from Ed Meitner via marc mc in the "Record Clamps" thread. Simply put, Ed (and marc mc) advocate a clamped platterless/matless approach which is easy to test on the otherwise stock H-K TT simply by putting a 3"-4" diameter spacer disc cut from a plastic jar lid under the record on the stock mat centerpiece with the weight in place, the stock mat is necessary to damp the platter as well as spacing and giving the standard play option for warped discs. The spacer disc need be just thick enuff to lift the record off the mat to the rim, easily tested by tapping a sacrificial record in place and listening to it compared to no spacer disc. This will render a VTA essentially the same as at the first portion of the normally clamped record across the record instead of an inaudible slight drop inward due to the dishing of the stock mat. Then play a well-known record listening particular for 'body' and resolution in the midrange, honest and clean full bottom end, and extremely clean and natural cymbal sound at the top. Along with the full-mod package this should give the most holographically natural 3-dimensional clean and detailed sound of which the rest of the system is capable. As crazy as it sounds you can 'take it to the bank' on my word.
For warped favorites the spacer disc can be used topside under the weight as a force distributor as with normal use to flatten these records on the dished stock mat.
There is a further enhancement for the fully-mod'ed H-K and this one beggars logic but actually works, it comes from Ed Meitner via marc mc in the "Record Clamps" thread. Simply put, Ed (and marc mc) advocate a clamped platterless/matless approach which is easy to test on the otherwise stock H-K TT simply by putting a 3"-4" diameter spacer disc cut from a plastic jar lid under the record on the stock mat centerpiece with the weight in place, the stock mat is necessary to damp the platter as well as spacing and giving the standard play option for warped discs. The spacer disc need be just thick enuff to lift the record off the mat to the rim, easily tested by tapping a sacrificial record in place and listening to it compared to no spacer disc. This will render a VTA essentially the same as at the first portion of the normally clamped record across the record instead of an inaudible slight drop inward due to the dishing of the stock mat. Then play a well-known record listening particular for 'body' and resolution in the midrange, honest and clean full bottom end, and extremely clean and natural cymbal sound at the top. Along with the full-mod package this should give the most holographically natural 3-dimensional clean and detailed sound of which the rest of the system is capable. As crazy as it sounds you can 'take it to the bank' on my word.
For warped favorites the spacer disc can be used topside under the weight as a force distributor as with normal use to flatten these records on the dished stock mat.
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I haven't tried it yet, but there was a mention here a while back (with graphs) showing that a more common Baerwold or Stephenson cartridge alignment produced less distortion than the odd H/K alignment. It might be worthwhile to look that up and then buy a standard-angle headshell. I have one, just need to toss a cart on it and give it a go.
The stabilizers pop up on eBay now and then.
The stabilizers pop up on eBay now and then.
Gravelyguy
Active Member
Poi, it is too nice her in MN to spend too much time inside, but I think I did you latest mod right. I cut margarine lids to size but I needed 3 before I heard any difference. I had my brother in law as my second set of ears and after the 3rd lid was put on we both could tell a difference. Much more open and as you said more three dimensional. Our sacrificial disk was Journey Escape. I never knew there was more on that album than Steve Perry singing. It really brought out the instruments and made the music much more enjoyable. I will try to update after I get a chance to listen more. Does it make sense to have to add three lids?
Dave
Dave
Pio1980
AK Member
You need enuff clearance off the mat to make it 'float' free under the weight. Please get back in a few days with further impressions as you have the only fully-mod'ed H-K I know of other than mine and I need your feedback. BTW if you have Dixie Dregs "Night of the Living Dregs", play the studio side for yourself and your daughter. The percussion is absolutely breathtaking thru this thing.
rnorton
Super Member
I used the Stephenson on my T25 with good results. The ordinary headshells, though, often seem to be a few millimeters too short.
The stabilizer is now a moot point as I just lost out bidding on a weightless T-60.