ack's system - end of round 1

[PeterA]

The below is an additional simple mass-loading modification of the panel pillars - I'd been using 2 horizontal granite bars for years, bridging other vertical granite plates attached to the pillars; and now there are 6 horizontal bars, for another ~35 pounds of mass. I knew there ought to be an improvement, but I didn't know what to expect. Well, I now hear violins go higher, and 10-16kHz test tones are more easily discernible... interesting, those were slightly attenuated before, probably absorbed by micro-vibrations. But the more surprising and interesting sonic benefit came in the bass, with slightly more fuller and rounder character.

I guess this proves yet again that cabinet rigidity is a good thing; I honestly don't understand why people prefer lively cabinets. Anyway, nothing ground-breaking here, except that when I played the first CD - the Mahler 6 down below - the deep bass drums plus the hammer strikes were just jaw-dropping, with more tautness, power and jump factor - and thanks to whomever originally posted a while ago about this incredible Keith Johnson recording of the DSO!

View attachment 31086

Interesting mod. Congratulations on the improved sonics. Out of curiosity, why did you not rotate those bracing bars 90 degrees to offer less reflective surface to the panel's back wave? I would guess you want as much openness on the rear of the panel to allow it to act as an uninterrupted bi pole back wave. You could make it one solid back panel brace, but that would defeat the purpose, if I understand it right.

 

[microstrip]

The below is an additional simple mass-loading modification of the panel pillars - I'd been using 2 horizontal granite bars for years, bridging other vertical granite plates attached to the pillars; and now there are 6 horizontal bars, for another ~35 pounds of mass. I knew there ought to be an improvement, but I didn't know what to expect. Well, I now hear violins go higher, and 10-16kHz test tones are more easily discernible... interesting, those were slightly attenuated before, probably absorbed by micro-vibrations. But the more surprising and interesting sonic benefit came in the bass, with slightly more fuller and rounder character.

I guess this proves yet again that cabinet rigidity is a good thing; I honestly don't understand why people prefer lively cabinets. Anyway, nothing ground-breaking here, except that when I played the first CD - the Mahler 6 down below - the deep bass drums plus the hammer strikes were just jaw-dropping, with more tautness, power and jump factor - and thanks to whomever originally posted a while ago about this incredible Keith Johnson recording of the DSO!

Congratulations on the successful mod. I always dreamed about copying the most famous electrostatic clamping of the audio history - the SME modified Quad ESL63s. They use more than 300 pounds of brass and steel each!

 

[ack]

I thought about rotating them, but there is no physical reason why reflecting one way over another in this situation would make any difference. If nothing else, I have thought about covering them up with absorptive material, like felt or just plain black cloth... But who's got the time to cut up all these pieces.

 

[ack]

Congratulations on the successful mod. I always dreamed about copying the most famous electrostatic clamping of the audio history - the SME modified Quad ESL63s. They use more than 300 pounds of brass and steel each!

Hah, I think I have seen that before, but did not realize it was done by SME. There is quite to be said about mass-loading around the panels, that's quite certain by now...

 

[LL21]

Great stuff, Ack! We have a total of over 120kgs of mass damping across the entire system! Across every single component...especially the sub and even to a degree on top of the Wilsons. Most of the heavy solid brass weight is placed on top of Artesania mass damping plates on top of components so there is not a direct contact between the metal and the component. Each components weight was determined just by listening where some required little and others benefited not at all...that is, until we hit a critical amount of mass that then DID make a difference.

 

[MadFloyd]

Great stuff, Ack! We have a total of over 120kgs of mass damping across the entire system! Across every single component...especially the sub and even to a degree on top of the Wilsons. Most of the heavy solid brass weight is placed on top of Artesania mass damping plates on top of components so there is not a direct contact between the metal and the component. Each components weight was determined just by listening where some required little and others benefited not at all...that is, until we hit a critical amount of mass that then DID make a difference.

What do you feel are the benefits from mass damping, Lloyd?

 

[MadFloyd]

Great stuff, Ack! We have a total of over 120kgs of mass damping across the entire system! Across every single component...especially the sub and even to a degree on top of the Wilsons. Most of the heavy solid brass weight is placed on top of Artesania mass damping plates on top of components so there is not a direct contact between the metal and the component. Each components weight was determined just by listening where some required little and others benefited not at all...that is, until we hit a critical amount of mass that then DID make a difference.

What do you feel are the benefits from mass damping, Lloyd?

 

[LL21]

What do you feel are the benefits from mass damping, Lloyd?

Hi Madfloyd...When done right, i have found that the signal becomes denser tonally, and even imaging can improve (slightly). Its almost like you get 'more' of the voicing that your system already has. I cannot say that the signal gets 'diluted' through vibration but it is a way of describing what i hear. I have found a few instances where nothing happens whatsoever...until you hit almost 20kgs, and then you hear that 'denser' note signal/less-dilution thing.

In all cases, i am either using HRS or Artesania mass dampers...and then if i am adding pure dead weight (typically brass), it is STILL sitting on top of mass damper. Interestingly, if you look at Artesania...they have essentially done a far more professional job of what i 'made up' myself.

they now sell a 10kg version of their 2.5kg and 3.5 kg damping plate which basically puts more mass on top of the plate. I have a 10kg scientific polished brass weight i picked up 2nd hand from a manufacturer that sells their trade-ins cheaply...and put it on top of the 2.5kg mass damper.

 

[ack]

Battle of the Titans - Modified Alpha vs Vivaldi 2.0 - RBCD/HDCD only

The modified Alpha (AES/EBU) vs the Vivaldi 2.0 (S/PDIF), both standing up right in the back - level-matched with a 1kHz tone and the Revox's VU meters, excellent cabling, no external clocks and other gimmicks, both driven by the Spectral SDR-3000 transport; easy A/B at the preamp. Comments to follow, but let's just say I wouldn't bring in a Vivaldi without [redacted]

 

[MadFloyd]

redacted?

 

[ack]

redacted?

LOL, to keep you in suspense... to be continued

 

[MadFloyd]

LOL, to keep you in suspense... to be continued

Taking a page from Marty's book I see

 

[ack]

Taking a page from Marty's book I see

Which filter do you recommend for RBCD? So far, I like F1 over, say, F6 which is softer.

 

[Al M.]

Which filter do you recommend for RBCD? So far, I like F1 over, say, F6 which is softer.

The manual has some interesting info, including impulse response graphs for filters:

http://www.dcsltd.co.uk/wp-content/uploads/2015/06/Vivaldi-DAC-Manual-v2_0x.pdf

 

[MadFloyd]

I don't really hear any difference between filters.

 

[ack]

I don't really hear any difference between filters.

I don't blame you. I find it extremely stressing trying to identify differences, but there do exist, discernible with very high frequency content, and easiest with solo metal percussion strikes; still, I have to repeatedly go back and forth to identify them with a high degree of certainty. I think I am going to stick with Filter 4 which appears to have the best transient response, according to the manual (thanks Al!); but there is still pre-ringing in it; perhaps Filter 5, with no pre-ringing, may end be closer to the Alpha's no pre-ringing filter, but they do claim non-linear phase, so that's a problem.

 

[marty]

Anyway, nothing ground-breaking here, except that when I played the first CD - the Mahler 6 down below - the deep bass drums plus the hammer strikes were just jaw-dropping, with more tautness, power and jump factor - and thanks to whomever originally posted a while ago about this incredible Keith Johnson recording of the DSO!

View attachment 31086

The Mahler 6 thread was here

http://www.whatsbestforum.com/showt...p-van-Zweden-album-with-Dallas-Symphony/page2

see microstrip's post #9 to see why the hammer blows recorded by Johnson are so off the charts. See post #11 for some other conductor comments you might enjoy. I just signed up for Carnegie and NY Phil concerts next year. As much as I generally can't get enough Mahler live, I couldn't bring myself to hear Mahler 6 next year in concert as it really takes some pre-medication with Prozac to properly prepare for this utterly devastating work from a composer who wrote such emotional music about his own imminent death.

 

[ack]

The Mahler 6 thread was here

http://www.whatsbestforum.com/showt...p-van-Zweden-album-with-Dallas-Symphony/page2

see microstrip's post #9 to see why the hammer blows recorded by Johnson are so off the charts. See post #11 for some other conductor comments you might enjoy. I just signed up for Carnegie and NY Phil concerts next year. As much as I generally can't get enough Mahler live, I couldn't bring myself to hear Mahler 6 next year in concert as it really takes some pre-medication with Prozac to properly prepare for this utterly devastating work from a composer who wrote such emotional music about his own imminent death.

That's it, thanks. The hammer blows are one thing - and indeed oh so frightening - but the scale and power of the timpani in the final movement are also spectacular.

 

[ack]

Oh, and it's great to hear Marty about the concerts you will attend next year. I have the greatest respect for all those who use that as the ultimate reference, and thankfully we have plenty of concert goers here at WBF. I just recorded the BSO Fantastique I attended 10 days ago - an encore re-broadcast on FM of a digital recording of the performance. I like Nelsons a lot, it looks like he's on track to become another von Dohnanyi in making the musicians work very hard at it. I hope to see him lead Mahler in the coming years, and he has huge shoes to fill among all the great conductors that have gone through Symphony Hall. The Shostakovitch cycle has been immense, and the DG recordings a must-have.

 

[ayreman]

As an owner of a Stentor III I find this very interesting.

Can you please tell us in detail the diferences you heard after replacing these parts with higher quality parts?

Ron, first of all, I'm not done modding my Stentors yet. The photos you saw is work in progress. A lot more is coming next spring...
Secondly, wouldn't it be wrong to post about my mods in ack's thread? I mean... that would be violation of the forum's rules, wouldn't it?

So, what I suggest is when all of the mods to my pair of Stentor III are completed, I'll create my own thread about it, posting all the details. What do you think? Feel free to PM me on this.