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

PSP · « **on:** 19 Jan 2006, 10:29 pm »

Gentlemen,
Because there a lot of Orion builders using AKSA amps, I thought that it might be good to collect in one place discussion on mods to the Orion XO (the Analog Signal Processor = ASP) and the power supply to the ASP.

http://www.linkwitzlab.com/orion_asp.htm

There are lots of folks here that are multi-amping with AKSAs besides Orion users (andyr, Tinker, Jens, Kyrill, and ShinOBIWAN come immediately to mind and if I thought for 2 more minutes I'm sure that I could think of a dozen others) that have much to contribute (for example, specific mods for amps for driving highs, mids, and lows... need for tweeter protection caps, etc.).

Because I'm just getting started on the Orion, I don't have that much to contribute right now. I promise to post as I go along.

Peter

andyr · « **Reply #1 on:** 20 Jan 2006, 08:10 am »

Hi Peter,

Orions are about the only thing that might tempt me away from regular aural stimulation by my beloved Maggies, so I tend to pick up on all Orion-related stuff!

Over on the Maggie User Group Forum there were a couple of recent posts by "mac" (an Orion owner) which might innerest U and the other Orion-owners:

http://www.audioasylum.com/forums/MUG/messages/91815.html

http://db.audioasylum.com/cgi/m.mpl?forum=mug&n=88370&highlight=orion&r=&session=

http://www.audioasylum.com/forums/MUG/messages/91817.html

Regarding your other suggestions for:
a) AKSA tweaks for multi-amping (ie. bass/mid/tweeter AKSAs),
b) Orion ASP mods, and
c) Orion ASP PS mods,

I think that's an excellent idea ... but is it possible to change this topic heading to become "SL Orion XO and Power Supply Mods, & multi-amping mods"?? And make it a sticky ... just like Occam has for his "Felicia" power conditioner??

Regards,

Andy

aurelius · « **Reply #2 on:** 20 Jan 2006, 09:16 am »

Great idea Peter,

I started questioning whether it was a tad rude posting this kind of stuff on an AKSA forum, but in truth, I suspect there is little that thrills Hugh more than an Orion builder (or other multi-amped system) sussing out AKSAs!

For the record, my own system is a pair of Orions, driven by 8 channels of AKSA 55N+. My pre is an unmodified GK-1R and my source an Audio Sector 1543 NOS DAC driven by a Squezebox 2. Speaker Cable is Tara Phase II; other cable; interconnects (both digital and analog) are $10 supermarket jobbies.

I have only made one pseudo-modification to my Analogue Signal Processor (ASP) so far, and that is the addition of a decent power supply made up of (for each side):
- 2 x 30V centre tapped transformers (one for each rail)
- 4 x Fairchild Stealth FRED diodes (2 per rail)
- 2 x Nichicon Muse KG Gold 10,000uF capacitors
- 1 x +ve ALW super regulator (+15V)
- 1 x -ve ALW super regulator (-15V)

The 3300uF rail capacitors were removed and the new supply connected in their place (bypassing the diodes and ferrite beads on the ASP). +ve supply and -ve supply grounds are kept separate all the way to the ASP board where they are brought together. (Some may recognise this as implementation of NAIM modder's dogma!)

The results (when legitimatley A'-B'ed) were a dramatic increase in mid-range articulation. Instuments separated, sound stage widened and a fast system became faster. You may be able to get the same results cheaper, but I do not regret the money spent at all.

andyr · « **Reply #3 on:** 20 Jan 2006, 10:27 am »

Quote from: aurelius

Great idea Peter ... (Some may recognise this as implementation of NAIM modder's dogma!) ...

Aha, Mark,

Do I read by this that you are a lapsed Naim owner?

I was powering my 3-way Maggies with (admittedly, 1st generation!) Naim 250/250/160 but, after hearing an AKSA 55 (before 'Ns' and 'N+s' came out!!) soundly trounce my Naim 250, I bought 3 AKSAs and, when I'd built them, got rid of all my Naim gear!

And I've never looked back!!

Regards,

Andy

AKSA · « **Reply #4 on:** 20 Jan 2006, 10:55 am »

Marcus, Andy,

VERY interesting.

Thrill is precisely the right word!

I'm homing in on a feed forward power supply which could be scaled for large and small amps. The design is, well, novel..... but tomorrow I have to find out if I can make it work!! Sims look good, but nothing like the real thing.

Mark, are you in a position to show me your system in Fitzroy some time in the next week or so before you return to Geelong? Please??

Cheers,

Hugh

andyr · « **Reply #5 on:** 20 Jan 2006, 11:02 am »

Quote from: AKSA

Marcus, Andy, ...

Mark, are you in a position to show me your system in Fitzroy some time in the next week or so before you return to Geelong? Please??

Cheers,

Hugh

Marcus ... me too!!

Pretty please!!

Regards,

Andy

PSP · « **Reply #6 on:** 20 Jan 2006, 02:35 pm »

I'm happy to see some enthusiasm around the subject! I did discuss this thread with Hugh before posting... I think the AKSA forum is a natural place to discuss multi-amping because:

PT914 · « **Reply #7 on:** 20 Jan 2006, 05:05 pm »

Hello,

This is a great idea. My system; CD-Pro2, Hag chime dac, GK-1R( but only the analog board for now), highly modified ASP, pair each of 21N+, 55N+, and 100N+ feeding a pair of Orion with modified midrange mounting.
When I first hooked up the Orions, I had a ground hum that I could hear within 6 feet of the speakers. Tried many things. Finally after dsconnecting the ground wire from the AKSA amp star ground to chasis on all amps, did I make major progress. Now I have to be within 2 inches to hear any hiss from the speakers. Presently the ASP is the source of any noise and any mods on this unit increases the background blackness. I made a felicia power conditioner for the ASP and this was a 10.

Philip

goskers · « **Reply #8 on:** 20 Jan 2006, 05:20 pm »

So, how are you liking your setup now with AKSA, Oriona and Felicia then?

aurelius · « **Reply #9 on:** 20 Jan 2006, 10:17 pm »

Andy,

No, not an ex Naim'er; it just seems that the Naim community modifies their preamp power supplies more than any other group on earth, so I have spent some time on Naim community sites prior to upgrading the ASP power supply.

Andy & Hugh,

I am moving back to Geelong the day after Australia day... so I can offer you either tomorrow [Sunday] morning (before it gets too hot!) or Australia day.

Andy, feel free to send me an e-mail. My user name is bnt and I am with bigpond broadband (bigpond.net.au)... sorry to be slightly obscure, but I get enough spam as it is; I don't need automatic e-mail scrapers to pick up my address of websites!

Philip,
It would be great if you could take the time at some point to clearly list all your ASP and AKSA mods and listening impressions of the mods. From what I can gather, you have built Felecias in to the power supply and changed the input coupling cap (C1) on your tweeter AKSA to V-Caps (what value? Did you do similar on the mid range?) From memory, most of your ASP caps are PPS (what type, brand), except for the 1440HP section, which you used 33nF V-Caps? Did you do this for both 1440HP sections (4 V-caps per ASP) or just to the last section? In theory, the same mod could be made to the 120HP section using 47nF V-Caps as well. Did you do this? Man, I'd want to be sure that $500 worth of teflon cut the mustard! You also bypass some or all of your opamp powers supplies with tantallum caps? What value, which opamps. I appreciate that a full list would take a while, but I suspect many people would be interested.

BTW, how have you found the chime? (I can see myself becoming a serial DAC collector).

AKSA · « **Reply #10 on:** 20 Jan 2006, 10:23 pm »

Mark,

How would Australia Day be, say around 9am, before it gets too hot?

Is that intrusive?

I'm sorry I've left it until now.......

Cheers,

Hugh

aurelius · « **Reply #11 on:** 20 Jan 2006, 10:47 pm »

Hows about 9:30am, so we can crank it up around 10:00am? Living in inner city, I would be reticent to go louder than a whisper before 10 an a public holiday.

AKSA · « **Reply #12 on:** 21 Jan 2006, 01:53 am »

Mark,

No problem.

Andy,

Can you make it at 9:30am on Ozday?

Mark, can you please email me your address?

Cheers,

Hugh

andyr · « **Reply #13 on:** 21 Jan 2006, 03:00 am »

Quote from: AKSA

Mark,

No problem.

Andy,

Can you make it at 9:30am on Ozday?

Mark, can you please email me your address?

Cheers,

Hugh

Sorry, Hugh, I can't ... so I'm going round tomorra morning (after the neighbours are up!

) ).

Regards,

Andy

PT914 · « **Reply #14 on:** 21 Jan 2006, 07:36 am »

Hi,

For the AKSA 25N+ Mod;
.01 uF Vcap at C1( got it at the introductory price of about $31)..took a long time to burn in. First two weeks had fatiguing highs, thought I made a mistake. That's when I did Ginger's super E-cap mod at C4 and it saved the day. After hundreds of hours of burn in, the highs are crystal clear. I can now appreciate drummer's technique on the cymbals and high percussion.
I also change the power supply caps. Since the rail voltage is 21V, I changed the caps to BG 4700 uF 35V N, bypassed with BG 47 uF 50V std and .47 MMK(came off AKSA C1 position). This mod made everything black around individual instruments or singers. There was no extra noise. Had to open my eyes when listening, to make sure no one was singing in the room.
For the AKSA 55N+, I did change C1 to .47 uF Vcap. Very difficult for me to hear midrange changes. Don't know if it was worth it.
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.

Later,
Philip

Joules · « **Reply #15 on:** 21 Jan 2006, 01:40 pm »

I find this very interesting. I've often thought about optmizing each amp for it's intended freq range. Hugh had suggested a teflon cap swop in my 55's for tweeter use and I must say I've never heard a better top end! I wonder if the same mod would work in my 100 mid amp, down to 200hz.

MikeC · « **Reply #16 on:** 21 Jan 2006, 06:30 pm »

Mark

I am the one (possibly not the only one) who put additional tantalum caps as bypasses for all the opamps in the ASP. I read somewhere that it was a good idea and it is also in the BB application notes. I think I followed their suggested values of 3.3uF tantalum and 0.01uF (the SL specified Panasonics) to ground for the + and - rails. Can't give any positives or negatives on this, but it can't possibly hurt. I don't think there would be as much benefit with your power supply though - mine is much simpler.

I also put Panasonic PPS caps in almost all places - where I could get the equivalent value. There are a few of the original polyprops, mostly in shunt positions. I don't have any real exotics in it yet.

As I mentioned previously, I don't currently have a system.

Right now, I have a just arrived but not set up turntable, an almost complete amp set and a GK-1 waiting for a volume control and some BG's before completion, so I mustn't let myself be distracted with more possible tweaks before I finish what I'm doing. Having said that, this thread will be closely watched. I would appreciate any feedback on the AD826 opamps from anyone who has tried them. I appreciate your comments on the offset being a potential non-issue, but I am also worried about the possibility of oscillation. An explanation I had about the greater output offset of these was the AD826 is a bipolar device while the OPA2134 is a FET. I'm not an expert here by any stretch of the imagination, so please feel free to correct at will.

My amp mods are Relcap TFT at C8 on the tweeter amp, 42V rails and additional 4700uF Nichicons in the PS of the bass amp and IR Schottky diodes in all power supplies. I will closely follow any other suggestions and will look into a 230V Felicia at some stage in the future. I also have a few BG NX 0.1uF caps that I ordered for something, so will try these as bypasses in the tweeter amp in the future.

Peter, I think the thread is a great idea - good one.

Cheers

Mike

PT914 · « **Reply #17 on:** 22 Jan 2006, 12:44 am »

Hi,

As I list out my mods, hope people don't thinking I'm bragging. To me it's embarrassing, this is like an addict's confession. I have no electrical back ground but after building Hugh's AKSA kit I have started on this diy quest that will never end. But it sure is fun.
Since Hugh has cleverly placed a sub out on the GK-1R I wanted to use it to drive the woofer on the Orion. I did this by having two ASP boards for one channel, of course only populating the woofer section for one and the mid/twt for the other. The only section that was duplicated was the U1A section. I have one power supply for the two boards. I also stacked the boards one on the other with spacers. This arrangement also decreased the ground hum. This arrangement also tested out fine on the SL circuit test.
On the woofer ASP I have Panasonic PPS caps. I initially was lacking bass and I built a pair of Rythmik Audio power subwoofers. I have the Rythmik crossover point at 25 Hertz(my range is 25 to 70) with no HP on the ASP. You can now feel the bass in your chest. The subs are not on the super felicia circuit, don't need it there. I'm very satisfied with the bass. Best that I have heard but only have had Linn isobarics in same room to compare with.
On the mid/twt board I now have a mixture of sonicaps, PPS, and Vcaps. Vcaps at 1440HP and sonicaps at 120 HP. To me the HP section has the critical caps. Sonicaps are very accurate and maybe sterile. Vcaps are sweet. Will be trying Multicap RTX at 120 HP.
Power supply is alw super jung reg at -+18 for each channel with felicia. No extra caps on ASP board, just the usual cap at opamp pin. The felicia improvement was better then the ASP cap changes, but did not take notes. Will have to pull the felicia out to see how the sound changes.
Would like to hear comments on different opamps too.

Later,
Philip

eweitzman · « **Reply #18 on:** 22 Jan 2006, 08:01 am »

A new forum for Siegfried Linkwitz' Orion dipole speaker owners and prospective builders has just got off the ground.

http://orion.quicksytes.com/index.php

- Eric

AKSA · « **Reply #19 on:** 22 Jan 2006, 09:04 am »

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 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.

Thanks Mark, I'm most grateful for your invitation and bountiful hospitality.

I hope the trip to Geelong in this heat went uneventfully, after all, your SX Nissan is turbocharged!!

I will contact you again soon concerning our chat!

Cheers,

Hugh