ack's system - end of round 1

[ack]

The Telarc Carmina Burana LP - a true reference

I've been trying to get this LP to sound right for the last 30 years, and performance-wise it's far superior to anything else I have heard to date (have another 3-4 recommended versions), including a live BSO years ago - to these ears, no one can beat Robert Shaw and the Atlanta's interpretation on this piece. In any versions of my system, when going loud, the chorus would tend to sound a little congested and distorted; microdynamics were not the best even in soft passages, timbre is not exactly right, and bass is just a tad too thick.

And here's where Isodamp comes in to fix all this, when strategically placed under the XP-25 phono. Placing 10lbs of marble ballast weight in the back of the XP-25 (to complement the additional weight of the tuner on top) and apparently moving one Isodamp underneath the XP-25 input section area, in the rear left, offers the most benefit. I experimented with using Isodamp in the rear and the stock feet up front, but the bass thickness remained. Only when lifting the unit with 4 Isodamp underneath - with one placed as stated - was I able to finally solve a lot of these problems. The chorus is no longer congested or distorted, the bass is thinner, faster and distinct, the timpani quite distinct on O Furtuna, and equally important, on soft passages, microdynamics are just superb; eager to listen to many other LPs, but phono microphonics appear to now be greatly reduced.

So this is finally rendered as the beautiful recording I always thought it was, and a new true reference

 

[Kingsrule]

Previn/LSO is my choice

 

[ack]

I have that too - not at the same level. I just finished listening to the Telarc to the end, and the final O Fortuna was always challenging to hear, shrill and distorted; not anymore. I have to stop here and thank PeterA for asking me a simple question recently: why not put this Isodamp under the XP-25; and that got me thinking.

 

[microstrip]

As far as I know this Telarc Carmina Burana was originally recorded at 16bit / 50kHz and later a SACD was also issued in DSD. Does anyone have experience with the DSD recording and know how the 16/50 was transposed to DSD?

 

[ack]

Yes it was recorded at 16/50kHz; don't know about the DSD, but I have two CDs of the same and they sound like total shite

 

[BMCG]

Ack - any thoughts on this DSD version? Also Atlanta...but this time with Donald Runnicles.

 

[ack]

View attachment 38291

Ack - any thoughts on this DSD version? Also Atlanta...but this time with Donald Runnicles.

I had that... "had" because I literally threw it in the trash, no kidding, sorry. It was one of those "couple" CDs I mentioned.

 

[LL21]

I've been using EAR Isodamp C-1002 - the blue stuff in the picture below - for about 6-7 years under my speakers and turntable with excellent results, and it was time to experiment with the XP-25 phono preamp and MIT cable network boxes. It is the same material Magico recently introduced in the QPods, albeit in a rather more complex configuration with copper and other materials. One critical requirement here is that Isodamp must be compressed (Magico points out the same), otherwise it's not effective and probably passes vibrations right through (it's a rather stiff material). I discovered it about a decade ago in some aerospace magazine, and it's apparently used widely in that industry, and when used correctly, it works extremely well in our audio applications.

So I first placed it under the XP-25, replacing its stock feet, and the increase in resolution and soundstage was easily and immediately noticeable; granted, I have the tuner and a steel metal plate on top of it providing additional and necessary pressure, but nonetheless the combination has proven very effective in reducing vibrations, and obviously the XP-25 is slightly microphonic. Others did not get the same result with the same phono but no additional weights (unfortunately ignoring my warnings), instead preferring the stock feet which are soft, which proves to me that when Isodamp is not compressed enough, it just passes vibrations right through. This microphonic nature of the phono must have been known to Pass for them to provide the soft feet, which are great and effective, but not as good as Isodamp.

Next, the MIT speaker cable boxes, if you can call the below "boxes" - also shown are the copper and mumetal shields discussed upthread (the copper shield is routed to ground). There, I had to bear down on the box with an additional 20lbs of marble on top to hear any difference, and then the improvement was rather easy to prove: configure one channel's box as shown and leave the other as is; then put the preamp in mono and listen loudly: impossible to hold a steady mono image; not exactly a blind test, but when I configured the other channel the same way, I got back my mono image.

The end result on the MIT boxes was less harshness in parts of the treble range, which proves that these boxes are susceptible to air-borne vibrations. Unlike the phono, it's not clear here if the improvement is a result of the marble damping the plastic MIT box, or the effect of the Isodamp, or both. Nonetheless, a good place to be.

View attachment 38224

Great stuff...love this kind of work. Hard to do (because it takes physical effort, time, and often several iterations)...but well worth it in the end. I have had to place different combinations of Stillpoints U6s, HRS Nimbus Couplers, HRS M3X platforms underneath...while on top using Artesania, HRS damping plates, and a couple of Stillpoints U5/6s...with dead weight (total 90kg) on top of the various damping plates which sit on top of various different pieces of equipment.

But it has really helped when listening critically to Ivan Moravec on Chopin Nocturnes for getting those upper piano keys to have real depth of note/power in the treble...while maintaining control and tightfistedness/clarity on Nirvana Unplugged...while maximizing intelligibility of choral music en masse.

Great reading. Thanks for this. Here is a photo of the mass damping i did on the Velodyne DD18+ subwoofer...which sits on top of Stillpoints Ultra 5s on top of Auralex Isolation platform.

 

[LL21]

The interesting thing about the Velodyne is that at high'ish music levels, the picture frames used to vibrate on top and move around the top of the Velodyne. On movie soundtracks, they would actually vibrate and fall off!

Now, they dont move at all...i have measured the distance between the picture frames...and they have not moved even an 1/16th of an inch after a year of music, multiple action movie soundtracks, explosions, rumbles and quakes. And the bass has also become both more powerful/propulsive while also tighter and more detailed/defined down low. A lot of fun.

 

[PeterA]

I have that too - not at the same level. I just finished listening to the Telarc to the end, and the final O Fortuna was always challenging to hear, shrill and distorted; not anymore. I have to stop here and thank PeterA for asking me a simple question recently: why not put this Isodamp under the XP-25; and that got me thinking.

You are most welcome, Tasos. I often offer unsolicited advice when hearing someone else's system, and I am glad that you accept suggestions as given because the intention is to learn and gain experience. Congratulations on your success with this challenging music. Thirty years is a long time to be chasing a goal but it sure can be rewarding if after all of the effort, one enjoys his system and his music collection that much more.

 

[ack]

@Lloyd: thanks for the picture and sharing your experience. Isn't it amazing how the bass is transformed with proper damping? And how more dynamic it sounds? Only people who have gone through proven tweaks like these will appreciate the increase in dynamic headroom; or those who use properly damped speaker enclosures.

@PeterA: Al made another comment the other day, when he realized the system started improving during the audition, as if there were power quality issues, and despite the fact the amps were running for 24+ hours. So tomorrow another MIT Magnum Z-Trap is arriving, and will be feeding all main components. Given the results of using one on the XP-25 power cord - which actually removed hum - and another one on the digital components, I thought I would try a third one on the main components. More to come on that. The Z-Trap is long out of production, but MIT will still make them upon request; no idea why they were retired, they freaking work wonders, and the filters are in parallel.

 

[LL21]

@Lloyd: thanks for the picture and sharing your experience. Isn't it amazing how the bass is transformed with proper damping? And how more dynamic it sounds? Only people who have gone through proven tweaks like these will appreciate the increase in dynamic headroom; or those who use properly damped speaker enclosures.

@PeterA: Al made another comment the other day, when he realized the system started improving during the audition, as if there were power quality issues, and despite the fact the amps were running for 24+ hours. So tomorrow another MIT Magnum Z-Trap is arriving, and will be feeding all main components. Given the results of using one on the XP-25 power cord - which actually removed hum - and another one on the digital components, I thought I would try a third one on the main components. More to come on that. The Z-Trap is long out of production, but MIT will still make them upon request; no idea why they were retired, they freaking work wonders, and the filters are in parallel.

Absolutely. Incredibly rewarding. Selectively assembling great equipment...fine tuning and honing and honing...and getting it right. The Ultra 6s were a recent welcome addition...providing I combine them with HRS Nimbus couplers. And while i was going to trade in the U5s for the U6s...i may now keep the U5s to try under the Tripoint Troy...uh oh...which already has some pretty good mass damping on top which made a nice improvement. So I do wonder if the U5s underneath will also improve things...a preliminary trial made no difference, but I have thought of another way to put them under the Tripoint which might be better...

 

[pcosta]

How do you use the Stillpoints and HRS Nimbus together. Curious. Picture?

 

[LL21]

How do you use the Stillpoints and HRS Nimbus together. Curious. Picture?

Let me try to get a photo...but in the meantime its pretty simple (and crude):

Take the Burmester 948 Power Conditioner. From the bottom up (ie, from floor up to the component) we have:

- Floor
- 1.5" slate slab that sits under the custom equipment shelf
- 4" thick slab of birch ply (shelf)
- HRS Nimbus Coupler
- Stillpoints Ultra 6 with Base
- Burmester 948
- 2 HRS Double Thickness 12" long DPXII damping plates

Hope that makes sense.

As a note that explains how/why...i originally had the Ultra 6 + Base on top of the shelf directly...and on top of the Ultra 6 was the Nimbus Coupler...and then the Burmester.

After several reasonably good test tracks...i went to Ivan Moravec Chopin Nocturnes...and discovered a thinness in the upper treble piano presentation that at low volume levels made treble keys sound like a good electronic keyboard (not piano). The depth/power of upper notes had been lost...thinned out, hardened slightly.

I then reversed the HRS Nimbus and Ultra 6 + Base...and i retained all of the clarity I had experienced using Stillpoints...while actually creating greater roundless, freedom to notes and space. The tonal DEPTH came back into those upper register notes so that even at volume 1...you know its a piano without thinking about it.

I assume some vibration is coming UP from the floor...through the shelves...and into the base of the Ultra 6...and then into the Burmester.
With the Elastomer sitting between the shelves the Ultra 6...perhaps that vibration from the floor is being partly damped by the elastomer of the HRS. Totally guessing...just care that it works well for me.

 

[pcosta]

Thanks LL21

 

[ack]

One for the ages

[video]https://www.facebook.com/bostonsymphony/videos/10155348199218269/[/video]

 

[cjf]

One for the ages

[video]https://www.facebook.com/bostonsymphony/videos/10155348199218269/[/video]

Hello Ack,

I've read in your posts that you have experimented with replacing the factory feet of your Pass Labs Phono stage using ISODamp material. Do you happen to know if the feet on the Phonostage are the same feet used in the various Pass Labs Amps as well? The feet of my Pass XA60.8 Monoblocks appear to be made of something that resembles Polly and Rubber combined but its hard to say exactly.

I've considered messing with changing the feet our for Herbies Tenderfeet or a slab of ISODamp but remain concerned that in doing so it could be a step in the wrong direction. It seems like no matter what the component is, as soon as you rest something on top of,on bottom of or against that components chassis the sound changes and not always for the better.

Granted I get that one can just remove the tweak and return to "normal" but it is an interesting experiment either way.

Would you mind sharing your source for the ISODamp you are using? Would you say the version of ISODamp you use suitable for a heavy amplifier (90lbs'ish)?

Thanks for your thoughts

 

[ack]

Hi, I don't know what feet Pass is using all around, it would be best to talk to them. Isodamp is very expensive from EAR because they don't care to do retail; I got mine from percyaudio.com about 8 years ago, and I see it's still inexpensive for the amount we are talking here. 90 lbs would be more than plenty to energize it - the manufacturer's specs don't mention specific PSI, only adequate compression, but experimentally, I would say upwards of 40lbs will do. Keep in mind it comes in different thicknesses, and I use -25 (quarter inch). See also this earlier post with photos of its use around turntable http://www.whatsbestforum.com/showt...end-of-round-1&p=104508&viewfull=1#post104508 and an earlier thread on it http://www.whatsbestforum.com/showthread.php?4369-Isolation-materials - it's a highly damped thermoplastic vinyl.

Indeed, there are isolation solutions that work and others that don't as well, and it may well be that stock-anything is better than anything we may try in our systems, depending on the application.

EDIT: Just did a quick search, and according to this https://forum.audiogon.com/discussions/sme-new-platter-material SME have been using Isodamp for years in their turntables

 

[PeterA]

Hi, I don't know what feet Pass is using all around, it would be best to talk to them. Isodamp is very expensive from EAR because they don't care to do retail; I got mine from percyaudio.com about 8 years ago, and I see it's still inexpensive for the amount we are talking here. 90 lbs would be more than plenty to energize it - the manufacturer's specs don't mention specific PSI, only adequate compression, but experimentally, I would say upwards of 40lbs will do. Keep in mind it comes in different thicknesses, and I use -25 (quarter inch). See also this earlier post with photos of its use around turntable http://www.whatsbestforum.com/showt...end-of-round-1&p=104508&viewfull=1#post104508 and an earlier thread on it http://www.whatsbestforum.com/showthread.php?4369-Isolation-materials - it's a highly damped thermoplastic vinyl.

Indeed, there are isolation solutions that work and others that don't as well, and it may well be that stock-anything is better than anything we may try in our systems, depending on the application.

EDIT: Just did a quick search, and according to this https://forum.audiogon.com/discussions/sme-new-platter-material SME have been using Isodamp for years in their turntables

Yes, and I think it is also used on the underside of each of the steel chassis, not just on the platter, of my SME 30/12 turntable. The interesting thing is that there is no weight on it and it is still very effective. Here are some more data points: I found the same thing when I placed some scraps on top of my Pass amps. The top casework rings, but with the Isodamp scraps just sitting on top - no weight or compression - the ringing is completely dampened. So, the need for weight or compression is not an absolute, at least in these two instances. I did experiment with some pieces under my 20 lb phono amp, both under the stock footers, and also stacked to act as new footers. I did not like the sonic results. I was told it needed much more weight to be effective, so I have had inconsistent results in my own system with Isodamp.

 

[ack]

Is the platter's Isodamp pliable? I bet it is, at least more so compared to what I use, which would indicate less need for compression - so a different version of Isodamp (C-1002 is just one of them), if that were true. And if you were to compress the pieces I gave you under your XP-25, I bet you would like the results, like your friend Alan did under his tube amps. I like the fact SME attach it to the steel chassis, to absorb vibrations picked up by the metal - very smart. It's effectively along the lines of what VPI are doing by sandwiching the aluminum base plate between acrylic, in my turntable.