Since I'm leaving for CES next week and unable to listen at home, I packed up and shipped off my Dali Megaline's electronic crossover to be "reverse engineered."

It is going to Tom Tutay of Trans Audio Design, famous for his Altec 1570 amplifier mods as well as USA repair station for Air Tight.

If I can afford it, I will have him build an octal based all tube crossover with outboard tube rectified power supply that is electrically identical to original.

I should have my original crossover and "fact sheet" back around Jan 10th.

albertporter December 31, 2004 04:37

Albert,

Best of luck in your endeavors. Maybe Dali will add you to their R&D department. I look forward to your pictures from CES.

shventus December 21, 2004 00:34

Perhaps the solid state crossover is doing the best job but experimentation is the only way to know.

Worst case, I wind up with two crossovers to experiment with. Modifying my original crossover leaves nothing to compare against.

I agree that the two amps I'm using could be part of the problem and as you say, a two way speaker with two distinctly different drivers is a big change from a single driver electrostatic with no crossover.

None the less, much of the magic for me is getting the texture and tonal balance of the sound to be acceptable while playing every kind of music. I got there with the Soundlabs with all tubes and every tube change was paramount to where I evolved the sound.

The Dali is higher resolution in many ways, begging for finesse. I have to believe it will be just as sensitive to these changes if not more so.

I am off to a great start, one of the guys I'm considering for the crossover project built an all tube replacement for friend's Maggie 3.6's.

The transformation was astounding, giving me hope that my ribbon drivers will respond in a similar fashion.

albertporter December 20, 2004 19:37

What has happened to the ability to edit one's posts after the fact? Anyway, following the first sentence of the second paragraph above, I forgot to include something like: "Not to mention the fact that this has meant you're now using two appreciably different kinds of amplifiers for the two divisions of the frequency spectrum." Seems to me this could be almost as significant a factor as the inherent differences in the speaker designs that I cited...

zaikesman December 20, 2004 10:23

"I have more concern with the midrange integration and a lack of smoothness and phase coherency that my Soundlab Ultimates delivered in the midrange and highs."

Mightn't this in part simply be an unavoidable perceptual consequence of going from a crossover-less, full-range transducer, to one with any crossover at all and two disparate driver topologies? Although the tubed crossover is bound to change the sound somehow - which if done correctly (a big if) a confirmed tubeophile might well consider an improvement - I'm a little bit skeptical that it will necessarily serve as a magic elixir for exactly what ails you in its entirety, because of what will still remain unchanged.

I can certainly understand why someone who has avoided (as assidiously as possible in a high-powered system) solid-state devices in their amplification chain, wouldn't want to be forced to compromise that philosophy when it comes to their new loudspeakers. I do, however, wonder about commissioning such a mod before break-in and final positioning may be complete, since those variables should have some bearing on the audible qualities in question. But I guess if the mere idea alone is too much to bear for attaining peace of mind when you've already got this much invested, then there's nothing else left for it but to go for broke and let the chips fall where they may. Best of luck Albert, and I hope you're correct in your diagnosis and cure - or at least do no harm (though it would always be reversible, if not maybe in the pocketbook).

zaikesman December 20, 2004 08:37

I was just going to drop you a line and see how things were going. This post saved me the trouble and probably answered a few other questions too. Thanks for the update : )

I hope that you have a safe and enjoyable trip. I'd really like to wander off to some of these various events, but unfortunatly that four lettered word called "work" gets in the way. The fact that i'm already taking off most of Christmas week and the entire week between Christmas and New Year's would make it hard to disappear again right after that. I'm glad that we've got someone like you there to snag images for us. The only request that i'll put in is that you should try and find some more of "Santa's Helpers" or the "Elves" that you took photo's of before. I thought that some of the equipment "stacked up" quite nicely against the competition : ) Sean
>

sean December 20, 2004 06:05

Now that I am at 315 hours of break in on my Dali Megalines, I am becoming more and more pleased with the bass response.

500 hours is reported to be the absolute minimum but I am already getting terrific dynamics and reasonably good deep bass. Hopefully this will continue to improve as I accumulate more time on the system.

In the meanwhile, I have more concern with the midrange integration and a lack of smoothness and phase coherency that my Soundlab Ultimates delivered in the midrange and highs.

I suspect the Dali's solid state crossover is "imprinting" it's personality onto my tube front end, keeping it from delivering the finesse and rich textures that will allow me to emotionally attach (the last bit) to my system.

When my tube front end was directly driving the Soundlabs, I could tweak every last bit of detail and nuance and every tube change was enormous.

Now, I find the front end restricted by the buffered transistor crossover. Dali has warned me that changing this is a bad idea but I cannot resist making this experiment.

I know two audiophile engineers who promise they can reverse engineer the solid state Dali crossover, replacing it with an octal tube based crossover that is a dead match in all electrical parameters. The plan is to use a tube rectified power supply to keep the dynamics true to life.

Plan is to remove the original crossover and ship it to one of the two engineers while I am at CES gathering images for Audiogon.

Wish me luck, I need it.

albertporter December 20, 2004 03:26

You guys are something else :^).

albertporter December 06, 2004 20:06

That's it Albert, you let the cat out of the bag - I'm sending you these RCA 6201's while my amps are in the shop for the cap upgrade, no asking! (...only I wish you could hear 'em full-range :-)

zaikesman December 06, 2004 17:47

I've intentionally not followed this thread for awhile knowing that I would experience several emotions at once and not being prepared to go through that for personal reasons. Albert, it's absolutely thrilling to see and read about the changes you've made. Audiophiles are an interesting lot ranging from gear heads to music lovers. The regular posters to THIS thread are some of my very favorite people at Audiogon. Albert, you exhibit more of the finest attributes involved in this hobby than any other poster I'm aware of. I'm so very happy for you kicking it up a notch but I'm also sure it is about about the music!

I really, really wanted to go to CES this year, more to meet the many online friends I've made than to enjoy the gear. Newer, better gear can make ones system sing but friends make your heart sing which is sweeter than any music I can think of. Look for me next year but watch out. I'll be easy to spot. Too much enthusiasm and not nearly enough knowledge.

Tom, can you arrange a side trip through Boise on your way back from the show? I promise a place for Magnum to chew on my camera gear. But, I'd really enjoy it if he chewed on my two cats. Is your arm twistable?

This thread is technically way over my head but I'm sure my ears are perfectly capable. Congrats Albert. You're still the man!

Patrick

lugnut December 05, 2004 15:06

Thank you,so much,for tour timely reply Albert.

[email protected] December 05, 2004 03:27

Hello Sirspeedy. I can't offer any first hand advice about the TAD. The only time I've heard it is at audio shows were the set up and sound is typically not good.

The Graham 2.2 arm is wonderful, I owned three different Graham arms, each one the improved version over the previous model. By the time the Tungsten mount was employed it had improved enormously.

My experience with adjustment of the Graham may be like yours, I will explain my experience and you can compare notes.

Following the manufacturers instructions and using the supplied overhang gauge and stylus alignment tool, it is easy to get good sound. Getting perfect sound is a LOT of work.

The stylus changes length (overhang) with azimuth and track force, making it difficult to hit all three at one time. Add to that, the rubber damping in the counterbalance stores energy so that once the proper track force is set, it tends to "continue" in the direction you last turned the track force knob.

I imagine this is friction between the arm, rubber and weight but it makes it impossible to hit it perfect in one sitting. I find the weight off in as little as 10 minutes or as long as a day depending on temperate, humidity and such.

Add to that, the Graham centers and levels itself by gravity. That sounds fine until you realize that the turntable it's sitting on may have one or more corners change spring tension or your floor (particularly pier and beam) may move a few thousandths of an inch.

This would seem to be no big deal until you realize that a few thousandths of an inch at the floor could amount to a full half bubble (on a precision level) at the deck of the turntable.

My experience was with the Basis Debut Gold and the silicone damped springs could be adjusted by turning the tower tops. Even if perfectly level, a change in the floor, the temperature or your hand resting on one edge for a bit too long could alter the "perfect" level, throwing the Graham off by several degrees.

Unfortunately ANY change in adjustment in the Graham is audible, proof of its excellent design and performance.

As for Purist, I ran Dominus RCA between the termination box of my Graham and phono stage and was never able to find another cable it's equal, much less beat it.

I have not heard the Schroder Ref but it looks absolutely amazing. I have heard reports from reliable sources that lead me to believe it is likely in the top two or three pivot tone arms made today.

albertporter December 05, 2004 02:30

Albert,lovely(no,FABULOUS setup).I was wondering,due to your extensive experience and passion for this hobby(obsession,in a good way)have you got any comments and preferrably any listening experience with the TAD model ONE speaker that got such a glowing review in TAS recently.Also,any thoughts on the top PURIST phono cable.I currently own a GRAHAM 2.2 w/IC-70 phono cable and since I'm convinced that the phono connection is the most important in a high res setup could there be an improvementin stepping up to a top PURIST design.While I'm at it let me ask you one more question.I have found through experience that in order to get the most from a top flight analog rig it is paramount(along with all else)to eliminate any bearing resonances in the arm.On my 2.2 I have found a corrolation between the exact amount of damping fluid along with vta and tracking force(if one was changed,the others could,slightly change along with that parameter.Sort of like a Rubick's Cube.I read an extensive article on this last year and it opened up a whole new level of phono optimization to me,after extensive and exausting tweaking.What I'm trying to get at(I realize that you,fortunately have an air bearing arm)is do you think,or have you heard comparisons,the SCHROEDER REF arm could be a superior choice to the 2.2(which I'm very happy with)since it incorporates a unique non damped and non resonant bearing with it's novel use of opposing magnets?I'd love to consider an air bearing design,which to me are superior(my friend owns an AIR-TANGENT)but I don"t want to get involved with the pumps and hose runs.Sorry to run the gamut of subjects here but your reputation on the net led me to ask.Thanks so much.

[email protected] December 04, 2004 23:25

I'd love to come and visit, Albert.
First, I have to get the house done, and get married.
That should all be done by around early May.

Then I can ditch the wife for a few days and come over for some real Scotch drinking and music appreciation!
Only kidding! I'd have to bring the wife with me.

Until then, I WILL be at CES, and my ticket has been bought, and I will be in Vegas from Jan 2 thru Jan 11.

Very much looking forward to seeing you there.

twl December 03, 2004 15:36

Tom, I wish you would visit me and listen to some tunes. I am gaining ground on the break in issue every day.

I just received a Phillips CD player and a stack of burned CD's from Sean.

THANK YOU SEAN.

He shipped without asking because he knew I would likely refuse his kind offer. I am using his Phillips because of CDR (burned CD's) incompatibility with my Sony and a borrowed Toshiba.

The new Mullard XF2 tubes, combined with Telefunken inputs for my Air Tight ATM3's is a stunning improvement. One of the guys in my group said it was bigger than swapping between some amps.

This evening I passed the 280 hour mark on the Dali's minimum required 500 hours. Already the Dali's have improved so much it is hard to imagine a store being able to sell a newly opened pair.

albertporter December 03, 2004 07:53

Albert, if those amps are "air tight", how do you seal them back up when you change tubes?

I couldn't use that on my amps because they are Berning up when I play them.

Hardee har har!

Hey, I might bring Magnum to the CES, and let him stay in your room. Okay?
I'm almost sure he wouldn't chew on your camera.

:^)

twl December 03, 2004 00:01

I think we've got a little disconnect going on in this discussion between the input tubes (12AT7's) and the driver tubes (6350's). Albert's talking about the inputs, but I was referring to the drivers because Albert used that description. There is a lot more choice to be had with different 12AT7 equivalents (both new and NOS), whereas the 6350's tend to be mostly Sylvania, though NOS RCA do exist.

Albert was using the Telefunkens for the inputs when he was running the VTL's full-range, and was kind enough to sell me some of his spares. It is a highly detailed, very fast and tight tube. I used Sylvania 6201 gold-pins previously, and that was a good-sounding tube - better than the common Philips JAN - but both tubes in my pair went quite microphonic, so I can no longer do informative comparisons with the other NOS tubes I now have on hand. After them I went to Mullards, then the Tele's, and for the time being I've settled on RCA 6201 black-plates. I haven't heard the Brimars.

What I said above about replacing the 6350 drivers still stands: this tube (the Sylvania) can be had for under $10 unless you buy it from VTL (theirs are $20 and rebranded VTL), so it's not a big investment to keep them fresh. This pays the sonic dividends I described above, though it's naturally not the magnitude of difference you will hear among the various types of input 12AT7's. I have not been able to get hold of any NOS RCA 6350's for comparisons.

zaikesman November 25, 2004 00:13

Mejames, I think Zaikesman has answered for me. The input drivers in the VTL 750 have a great effect on sonics. Even switching brands (same tube number) between Telefunken, Brimar and Sylvania alters the overall tonal character, dynamic contrast and transparency.

Owing to the fact the ribbon on my Dali is currently being driven by Air Tight ATM-3's, which is a very transparent EL34 based amp, I need to bring the VTL more in line with the ATM personality at the crossover point (1100 HZ).

I think Sylvania would do the job as it is very neutral. If I'm wrong, I can plug the Tele's or Brimars back in. This is what makes owning tube gear a blessing and a curse.

albertporter November 24, 2004 20:33

Yeah Albert, are those NOS, or just fresh ones? As you know, I recently got a new pair of 6350's from VTL, and even though my 'old' ones were only about 2 years old (I only replaced 'em because one began to go microphonic), the new pair did afford more authoritative dynamic contrast and more deeply saturated tonal color - slight gains but definitely perceptible. At their relatively cheap price, I plan to routinely replace the drivers every couple of years given these results.

zaikesman November 24, 2004 18:25

hello Albert could you elaborate on your comment below? Thanks much
"Sylvania drivers for my VTL's"

mejames November 24, 2004 17:08

Zaikesman, your correct about the cathedral ceiling and it's effect on speakers. Luckily the Soundlabs and Dali Megaline are both good candidates for this architecture.

The only effect (with both speakers) is slightly higher bass output in the lowest frequencies on the left side of the room. I assume this is due to boundary reinforcement.

I corrected this pretty well with the Soundlabs using RPG bass traps. I simply rotated them to be more effective on the left side, equalizing the apparent output.

Strangely enough, the Dali avoids this small error better than the Soundlabs.

I must say, tonight was a major turning point in the system. I had two members of my audio group proclaim the sound was already better than my Soundlabs. I'm not sure I agree with them but will say the Dali's are extremely good and are showing great promise. Certainly they are dynamic and extremely low distortion. The resolution in some frequencies exceed anything I have ever owned.

Hope my Mullard XF2 tubes for the Air TIght arrive soon. Those tubes and the Sylvania drivers for my VTL's plus at least 250 more hours and we shall see what these guys are capable of.

albertporter November 24, 2004 05:04

I think I would put Albert's System in the room used by Siriusly. I would add some absorptive chairs and couches.

gregadd November 24, 2004 04:12

Well, actually it was a form of LEDE, but more akin to what's normal for a concert hall, where the orchestra is surrounded by an acoustical environment that reflects outward, while the audience sits amid acoustical damping (part of which is their own bodies).

Anyway, getting back to Albert's room (this thread was about Albert's system, wasn't it?), the thing I wonder about from the pix is the cathedral ceiling that's loftier on the right than on the left, but I assume that staying with line-source speakers (vertical dispersion-limited) is what minimizes the practical effects of this environmental imbalance between channels. Regardless, I'm a fan of the mid-century modern architectural look (my house was built in '59 and has a cathedral ceiling in the dining area, but that's not where my system is located).

zaikesman November 24, 2004 01:20

Zaikesman-
I posted the message in case I had mislead anyone about how to achieve LEDE. It is clear my mehtod was not LEDE. Thanks for clearing it up.

gregadd November 23, 2004 23:33

Greg - "I also remember the discussion of the live end dead end room. Reflective surface behind the speaker and dead end behind the listener."

That is the sentence of your post from 11/21 which prompted me to respond in order to clarify. Maybe it just didn't come out the way you intended, since your quote from Acoustical Solutions basically reiterates the essence of what I wrote in response, or maybe I just don't read you right. Didn't want there to be misunderstanding, but now it seems we agree, so it's all good.

zaikesman November 23, 2004 22:17