SL Orion XO and Power Supply Mods, & multi-amping

lonewolfny42 · « **Reply #20 on:** 22 Jan 2006, 09:35 am »

Hugh :

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Today, in 42C heat (that's 105F to you guys Stateside!)..

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I visited Aurelius (aka Mark) to audition his Seigfried Linkwitz Orion, with Music PC, Scott Nixon DAC, and Squeezebox 2. All amps were AKSAN+s.

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I cannot think of a single criticism of this system and am now completely converted to the Dark Side.

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Chris[/list:u]

eweitzman · « **Reply #21 on:** 22 Jan 2006, 09:46 am »

Quote from: AKSA

The system is just incandescent ...

Incredible speed, in all bands. Articulation to die for. Layering and complete absence from intermodulation across the entire range, even to very high SpLs. Engagement which was palpable. I cannot think of a single criticism of this system and am now completely converted to the Dark Side. If there is anyone here thinking of an active system, this is the one, and it is just stupendous.

Hey, you just described my system Hugh!

I have great respect for your AKSA55 as you know, but I'm confident that the lion's share of what you heard is due to the Orion. I had my daughter's AKSA on each of the drivers in my system as I was trying out different amps, and I could hear no identifiable difference in amps -- other than my low-watt 300B amps being an utter failure driving the Orions, and crosstalk in a six channel amp getting in the way of the midrange driver.

Speaking of going over to the Dark Side: I turned my back on 10 years of tubes and high efficiency speakers for the Orions.

Now, where's that eight channel AKSA amp kit for the Orion?

- Eric

andyr · « **Reply #22 on:** 22 Jan 2006, 10:13 am »

Quote from: eweitzman

Hey, you just described my system Hugh!

... Speaking of going over to the Dark Side ...

Haha, hi Eric,

Hugh's "dark side" is active vs. passive crossovers! He's just seen the light in terms of actives!!

But BTW, you said: "the lion's share of what you heard is due to the Orions". All I would say here (given that my own Maggies are 3-way active driven by AKSAs) is that the 3-way active Orions give a musically more satisfying experience than my 3-way active Maggies but I believe Mark's Orions would not sound as good if they were driven by many other amps.

Regards,

Andy

ShinOBIWAN · « **Reply #23 on:** 22 Jan 2006, 11:27 am »

Quote from: AKSA

Today, in 42C heat (that's 105F to you guys Stateside!), I visited Aurelius (aka Mark) to audition his Seigfried Linkwitz Orion, with Music PC, Scott Nixon DAC, and Squeezebox 2. All amps were AKSAN+s.

The system is just incandescent, to use a word which also applies to George Clooney's new film, 'Goodnight, and Good Luck'.

Incredible speed, in all bands. Articulation to die for. Layering and complete absence from intermodulation across the entire range, even to very high SpLs. Engagement which wa ...

For several reasons

its a shame I don't live in Australia.

You could take a listen to what sounds like a very similar setup to what Mark uses with the exception that I use linear phase digital filters and digital room correction.

The active stuff is thoroughly addictive once you get sucked in. I imagine you'll be planning your new loudspeaker Hugh?

Dan Kolton · « **Reply #24 on:** 22 Jan 2006, 03:22 pm »

I've had my Orions cranking for a week. I started with Audio by Van Alstine amps on all drivers, and am now trying a Sony 5 channel (set to 4) on the tweets and mids. Different gains required resetting the crossover/equalizer pots, but I'm not able to discern any difference in sound. Several weeks ago, I heard another pair of Orions driven by DIY amps. Different room, so they sounded a bit different, but very similar to mine. I'll be hearing the Linkwitz recommended ATI 12 channel in a couple of weeks, and I'll report on that if anyone cares. My opinion is that, given enough power and a competent design, any amp will sound the same with these speakers (that is,wonderful!). I'm sure Hugh's amps would also sound great, and would provide the builder the pleasures afforded by DIY.

Tinker · « **Reply #25 on:** 23 Jan 2006, 06:48 am »

Quote from: Dan Kolton

I've had my Orions cranking for a week... but I'm not able to discern any difference in sound. My opinion is that, given enough power and a competent design, any amp will sound the same with these speakers (that is,wonderful!).

SL himself has expressed a similar opinion, and I'm praphrasing him obscenely when I say he reckons that any halfway competant amp will be "sufficient."

I don't have an Orion. I have a phoenix (well a variant on it). But I have built H-frame woofers too. I have always been partial to Siegfried's ideas (and those of Earl Geddes) because most speakers create a few orders of magnitude more distortion than the amp, and thus speakers always struck me as an neglected area for serious R+D. I a world where rooms are rarely custom-built for listening, directivity is a huge issue, and the dipole is one method of attacking the problem.

This said, I would agree that the Orion/Phoenix concept is so good that it de-empahsises the role of the amp. That said I have driven mine with Golden Tube SE 40s, Rotel 100 wattters, a home brew, AKSA 55 and 55N and 55N+. Having done side-by-side comparisons on single channels (well three channels at a time) and a step by step upgrade one AKSA channel at a time I would have to say that once you are used to the huge speed, accuracy and lack of colouration of the dipole speaker you *do* begin to notice the amp again. The N+ was a revelation in my system.

A good preamp however... now that's another story.

T.

aurelius · « **Reply #26 on:** 23 Jan 2006, 07:16 am »

Hugh, just to correct the record, it was a Audio Sector DAC (Peter Daniel).

Philip and Mike,

Thank you for the benefit of your experience; it is truely appreciated. While I don't have the resources at the moment to V-Cap my system end-to-end, your input helps me target the the key issues first. From your experience, the wisdom seems to be:
1) Felica the ASP power supplies
2) V-Cap and super-E (ginger mod) the tweeter amps
3) V-cap the 1440 HP sections of the ASP
4) BG the tweeter PS

A big Felecia on the bass is probably not something I could do for a while.

My first experiment (as suggested by Hugh) will be to place a zobel impedence correction network across the midrange. As is, there is a 40 deg. phase difference between the driver impedance at 120Hz and 1440Hz. When driven by an amplifier that uses global feedback (such as the AKSA), this can have delitarious effects. A 6ohm, 50W resistor in series with 2 parallel 6.8uF Jantzen caps across the driver terminals should do the trick (6ohm, 13.89uF is the ideal). I will report back if this makes any difference at all.

If anyone else tries this before me, please report back.

Cheers

Mark

AKSA · « **Reply #27 on:** 23 Jan 2006, 07:36 am »

Hey Lonewolfy,

Yep, first time I've heard a Music PC and a SqueezeBox.

I did not compare A/B, so it's hard to say if it differs from a regular CD player.

I cannot say that I noticed any deficiencies, however. But, heck, only just heard one, Chris, so can't be that sure just yet!!

Thanks Mark, the Peter Daniel DAC it is.

I don't believe you will need a 50W resistor. A couple of watts should do the trick, as there's not much power dissipated here.

The Orion sounded bloody fantastic!! Thank you for your hospitality, much appreciated!

Cheers,

Hugh

aurelius · « **Reply #28 on:** 23 Jan 2006, 08:23 am »

Hey Hugh,

RE: hospitality, you're always welcome!

RE: the Orions... my friend recently spent $15K on a rotel + sonus-faber cremona system... I think my system at 1/2 the price eats his for dinner!

RE: the resistor, I guess I was just being super catious. A 1kH tone @29V peak would dissipate roughly 30W through the compensation resistor. A similar 100Hz tone would dissipate a tiny 0.4W. If I were a genius, I would integrate the resistive power curve x average music spectral density over the range 100Hz to 1kHz to determine the required value... as it is, 20W is probably overkill. Might experiment with 10W and if there is notable improvement, use 20W permanently for peace of mind.

Cheers

M

eweitzman · « **Reply #29 on:** 23 Jan 2006, 08:35 am »

Quote from: Tinker

That said I have driven mine with Golden Tube SE 40s, Rotel 100 wattters, a home brew, AKSA 55 and 55N and 55N+. Having done side-by-side comparisons on single channels (well three channels at a time) and a step by step upgrade one AKSA channel at a time I would have to say that once you are used to the huge speed, accuracy and lack of colouration of the dipole speaker you *do* begin to notice the amp again. The N+ was a revelation in my system.

Did you have enough amps to try a full complement of each brand at a time, ie, four AKSAs, four SE40s, four Rotels, and four home brews? Testing that way would be the only definitive test IMHO.

My comparison was limited to one stereo Adcom, one stereo AKSA55, one stereo Pass Aleph 3, one multi-channel Rotel, two stereo Hafler TA1600, and two 300B monoblocks. I ultimately ended up with five Hafler TA1600s (one a spare). Got them new for $750 total, including tax and shipping. Can't beat that price, not even with eight channels of DIY gainclones.

I spent an entire weekend and a week of evenings swapping the amps from one driver to the next and matching gain using the pots in the Orion's ASP, pots on the Rotel, and an external pot (when needed). The 300B got ruled out pretty quickly. The only time I heard a major difference with the rest was when the Pass was on the mids. It turned out that I had set the gain of the tweeter amp too low -- superb mids on that Pass so I thought.

Testing amps on the Phoenix and drawing conclusions about the Orion doesn't seem valid to me, though I can't justify my skepticism. A guy I know has built the Phoenix, and after hearing the Orions wants to build a pair. I've heard two other Phoenix builds, and though the Phoenix is great, the Orion is that much better, albeit with less SPL capability in the deep bass. Who can say how they'd respond to different amps, given that the drivers are all different?

If Hugh wants to loan me a quad of AKSA55N+ amps, I'll compare them and take good care of them too.

PSP · « **Reply #30 on:** 23 Jan 2006, 03:00 pm »

Since I am currently working on the 100N+ that will drive the Orion bass (20-120Hz), this would be a very good time (my POV, of course!) to list any amp mods specific to bass performance.

ShinOBIWAN posted a similar suggestion (on the 55N+ thread) for specific mods aimed at bass, midrange, and tweeter amps.

The 100N+ I am building has the following differences from stock:

Occam · « **Reply #31 on:** 23 Jan 2006, 06:15 pm »

Quote from: PT914

...No mods to the AKSA 100N+ but the best thing for bass that I did was...had been using a Equitech balance torodial transformer to run all the amps(they had a sale on only the trans). After building felicia power conditioner and seeing how great they were, I built a BIG one. Got a Signal isolation transformer that would handle the amps load and connected that in front of the Equitech trans. Put the caps between and I got bass, too much. I had been dialing the active crossover woofer atten to the 2 o'clock position, with 12 being neutral. Now it's at 12 and loving it. I have detail in the bass lines.

Dang PT.... You're on wild and crazy guy

The last half of my 'Felix' was just delivered, and the DHL guy was not pleased. Neither was She Who Must Be Obeyed.
.

The smaller is a 50lb 2kva which will feed the larger 70lb 3kva transformer configured for 1.5kva of balanced power.
Anecdotally, there was an article in Audio Amatuer years ago which put caps accross the power transformers secondarys with supposedly the same effect. I'm unsure as to whether this is totally a powerconditioning effect or one that additionally deal with power factor correction.

I just got off the phone with Billy at BGMicro and he keeps telling me that the 300+ 175va transformers on back order will (honest) be eventually delivered. He wouldn't tell me who in Austalia ordered 85 of them.....

I'm slowly developing a less iron-rich approch to powerconditioning, but, at present, am not satisfied with the performance.

The efficacy of any powerconditioning is very dependant on the nature of your mains power. Here in the Nasty Apple, Felicia has been a tremendous adjunct to those in the typical multiple dwelling units. In my own brownstone, which is removed from shared lines and somewhat distant from commercial/industrial draws, the effect is not nearly as pronounced, though now that I have it, I wouldn't have a system without it

Tinker · « **Reply #32 on:** 24 Jan 2006, 10:40 am »

Quote from: eweitzman

Did you have enough amps to try a full complement of each brand at a time, ie, four AKSAs, four SE40s, four Rotels, and four home brews? Testing that way would be the only definitive test IMHO.

Sorry, I should clarify. I had four channels of each so I could run the left speaker with one type of amp and the right with another.

I now run the whole system of six 55N+ with the AKSAa natural gain lowered 3dB.

T.

andyr · « **Reply #33 on:** 24 Jan 2006, 12:26 pm »

Quote from: Tinker

Sorry, I should clarify. I had four channels of each so I could run the left speaker with one type of amp and the right with another.

I now run the whole system of six 55N+ with the AKSAa natural gain lowered 3dB.

T.

Hi Tinker, ma man,

You have 6 x 55N+ modules - ie. 3 per side, for yore Phoenixes? Does the Phoenix:
* only have one bass driver?
* or does it have two which in parallel are at least 3 ohms??

I'm curious as to how you only need 3 modules per side?

And, could youse "please explain" what benefit reducing the AKSAs natural gain by 3dB gives?

Thanks,

Andy (future Orion owner!

) )

andyr · « **Reply #34 on:** 25 Jan 2006, 08:15 am »

Quote from: PT914

Hi ... I initially was lacking bass and I built a pair of Rythmik Audio power subwoofers ...

Hi Philip,

Do I read you right? You added some Rythmik subs to a pair of ORIONS!!?? Wow you must love base!

Mark's Orions which I heard the other day, I thought were incredible in the bass department!

Regards,

Andy

andyr · « **Reply #35 on:** 25 Jan 2006, 08:38 am »

Can any of you Orion owners shed any light on why Siegfried put the bass/mid crossover down at 120Hz? It seems to me the Peerless 10" woofers are not doing enough work and the Seas mid is doing too much?

In terms of balancing AKSA amp power between the two ... if you have 55s on each Peerless woofer, mebbe you should really have an AKSA 100 on the mid?

I know the "theory" says crossovers should be outside a certain band (but I thought this was 300 - 3KHz??), for maximum fidelity - so he's broken that one with the upper crossover at 1400/1500Hz! But then again, it's a rare mid-range that can span 300Hz to 3KHz!!

Regards,

Andy

AKSA · « **Reply #36 on:** 25 Jan 2006, 08:53 am »

Andy,

Any man who loves Porsches surely enjoys a little mumbo?

Cheers,

Hugh

andyr · « **Reply #37 on:** 25 Jan 2006, 08:58 am »

Quote from: AKSA

Andy,

Any man who loves Porsches surely enjoys a little mumbo?

Cheers,

Hugh

Sorry, Hugh ... you've lorst me!

Regards,

Andy

AKSA · « **Reply #38 on:** 25 Jan 2006, 09:07 am »

Andy,

You surprise me!! There is a clear link between visceral bass and hard acceleration in cars!! Isn't it clear when you wander down Chapel Street on a hot Friday night? Heck, I love it myself, that's why I own a fast motorcycle!

Cheers,

Hugh

andyr · « **Reply #39 on:** 25 Jan 2006, 10:18 am »

Quote from: AKSA

Andy,

You surprise me!! There is a clear link between visceral bass and hard acceleration in cars!! Isn't it clear when you wander down Chapel Street on a hot Friday night? Heck, I love it myself, that's why I own a fast motorcycle!

Cheers,

Hugh

Ah, Hugh,

I guess I lead a sheltered life: I don't "wander down Chapel Street on a hot Fri (AND Sat, BTW) night" ... I sit at home being stroked by Maggie!!

(And Vicki doesn't mind ... we have an "open marriage" in this respect!!

)

Let me rephrase my question - as it's something I want to understand. But I'll leave out any reference to people or specific products, to avoid any emotional response:

1. In a speaker which has 2 x 10" woofers, 1 x 8" (7"??) mid-range and a tweeter, the crossover points (6dB L-R) are 120Hz and about 1,500Hz.

2. So ... what is the "ultimate" AKSA setup for this speaker?

3. "Normal" philosophy would say "the woofers need much more power than the other drivers, so they should each have a 100w AKSA module". The others can have AKSA 55s.

4. However, the mid-range spans a relatively high octave-range. If there is a 55w AKSA on each woofer - which seems to be entirely adequate (as we have heard!

) - is it possible that the mid-range should better have an AKSA 100 rather than an AKSA 55?

IE. against "normal" theory??

5. An AKSA 55 on the tweeter seems entirely appropriate to me, given the low (1,500Hz) crossover ... whereas my Maggie's 2,600Hz crossover is perfectly adequately served by an AKSA 25.

I'm interested in you comments on the above "conundrum".

Regards,

Andy

And, BTW, re. Chapel Street hoons on a Fri & a Sat night ... earlier this week I drove by a black, hoon-mobile Honda Prelude on Dandenong Road; gold mags, aero-wing on the boot, huge exhaust, bass thumping - amaaaazing!!

So I look into the tinted windows as I pass (it wasn't going very fast at the time, so my 4-cylinder car could keep up!

) - expecting to see a young Asian with his cap turned around ... and what do I see but a Lebanese "Princess" - long blonde ringlets, Arab hook nose - applying her lippy as she's driving along!

So it seems both sexes cruise down Chapel Street on a hot Fri/Sat night, my friend!!