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

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MikeC

  • Jr. Member
  • Posts: 66
Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #220 on: 8 Feb 2007, 07:32 pm »
I have the suspicion that up to now, the people taking Hugh's power supply seriously are already AKSA owners. I must admit to being somewhat skeptical (I am a Mech Eng, so I also need to understand why things work), but I know what Hugh's amps can do, after taking a leap of faith and purchasing my first AKSA unheard. This was probably the first one in Africa. I know I have a good regulated linear supply for my Orion ASP (better than the recommended one), so my priorities at the moment are to get my subwoofers built and running, add the additional tweeter to go to Orion+ (once the dust settles and the pace of development slows down), and upgrade my amps to Life Forces. Then I will get around to upgrading the power supply. This is not meant to slight Hugh in any way - If SL hadn't discovered the rear tweeter or Hugh hadn't decided to extort more money out of gullible acolytes with the LF upgrade*, then I would be in the market for an Orion power supply much sooner.

Cheers

Mike

*Disclaimer - For those who may be concerned at me dissing Hugh on his forum, this statement is made with tongue planted firmly in cheek (in other words, it is a joke)!

Dan Kolton

  • Jr. Member
  • Posts: 180
Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #221 on: 8 Feb 2007, 08:58 pm »
Mike,

I've similar reasons for not changing PS at the moment.

Builder Brad

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #222 on: 13 Apr 2009, 08:04 pm »
I would like to revive this post, for complete, unashamed personal gain.

I have just put my ASKA55 back into my system, after using an LM3886 based chip amp, and can appreciate the quality of Hughs AKSA amps, for a start the AKSA is not thrown by the unusual characteristics of my LITZ cables - the chipamp gave me almost 2v of dc ofset because of my cables.

I would like recommendations for the best cables to use with my Orions and AKSAs - what do other users with similar systems use?

Brad




MikeC

  • Jr. Member
  • Posts: 66
Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #223 on: 19 Apr 2009, 05:43 pm »
Hi Brad

Although cables do change the system sound, they are unlikely to make the differences changing an amp or CD player will. I use DH Labs speaker cables hard wired to my Orions, and a mixture of DH Labs and Audioquest for Interconnects.

Regards

Mike

AKSA

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #224 on: 20 Apr 2009, 12:33 am »
MikeC,

I agree with you on cables.....  so help me God......

Brad,

Nothing wrong with complete, unashamed, personal gain.  I generally endorse it.  It makes the world go round!

In my experience when speaker cables make a big difference to a system, it's usually for reasons of compromised amp stability, which comes back to design integrity.  When interconnects make a big difference, it's often because the source has poor drive, often a problem with tube preamps.

Cheers,

Hugh

andyr

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #225 on: 20 Apr 2009, 12:38 am »

When interconnects make a big difference, it's often because the source has poor drive, often a problem with tube preamps.

Cheers,

Hugh


Oh dear, Hugh ... are you suggesting the GK-1 has poor drive?   :o  Or bcoz it's a unity-gain output stage, it will be fine driving long ICs?  :)

Regards,

Andy

bhobba

  • Full Member
  • Posts: 1119
Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #226 on: 20 Apr 2009, 01:31 am »
I would like recommendations for the best cables to use with my Orions and AKSAs - what do other users with similar systems use?

Cable differences are audible in blind listenting tests conducted with very experienced listeners.  But is is nowhere near the changes other things will bring.  As Dave Ellis at Ellis Audio says - you get much better bang for your buck using faster diodes.  Cables are the very last thing I would worry about in setting up a system.  I have used Jaycar cables with excellent results.  Not that I have ever head any difference with cables anyway.  But then again for me even difference in amps are not great (I can detect differences but for me at least it aren't easy).  However Hugh has mentioned he finds amplifiers to be the main determinant, which is hardly surprising for someone that designs amps by 'ear'.  I have never met anyone that has claimed cables are the main determinant.  Met plenty that claim speakers are, some that clam amps are, and a few the source.  But none for cables

Thanks
Bill

AKSA

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #227 on: 20 Apr 2009, 02:38 am »
Andy,

You have put words into my mouth - OTOH I should be more careful when I preach to the choir.

The GK1 is a cathode follower, unity gain output stage.  Zout is 130R, which is as low as it gets with tubes, and better than many SS preamps.  The problem does not apply here as I have verified in listening tests with expensive vis a vis cheap interconnects.

However, for plate loaded triodes, particularly, the output impedance is a function of the plate load and the tube operating point and characteristics.  Plate loads can be many kilohms, and this raises the eyebrows somewhat.  Such preamps often have output impedances of 5K or higher, and this means that interconnect capacitance will cause HF rolloff.  It may also mean higher distortion.

Cheers,

Hugh

whubbard

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #228 on: 20 Apr 2009, 03:19 am »
For my cables (interconnects & speaker cable) I use Belden 89259.
The speaker cables are cross-connected twisted pairs, soldered directly to the drivers, with Kimber spades on the amplifier side.
The interconnected are twisted pairs, with Eichmann Bullet Plugs (copper).
They are good DIY cables.

I haven't had much of a drive to play around with them. I would rather tweak my components and room setup/treatment than cables. Currently I'm finishing a DAC, building a new turntable (with new MC headamp), and then possibly some room treatments, then I'm going to play around with opamps in my Orion x-overs...cables are the last thing I'm thinking about.

Simply put: They are easy to change, but offer the least improvement IMHO.

-West

andyr

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #229 on: 20 Apr 2009, 03:21 am »
Andy,

You have put words into my mouth - OTOH I should be more careful when I preach to the choir.

The GK1 is a cathode follower, unity gain output stage.  Zout is 130R, which is as low as it gets with tubes, and better than many SS preamps.  The problem does not apply here as I have verified in listening tests with expensive vis a vis cheap interconnects.

However, for plate loaded triodes, particularly, the output impedance is a function of the plate load and the tube operating point and characteristics.  Plate loads can be many kilohms, and this raises the eyebrows somewhat.  Such preamps often have output impedances of 5K or higher, and this means that interconnect capacitance will cause HF rolloff.  It may also mean higher distortion.

Cheers,

Hugh

Ah fine, Hugh.  I knew the Zout of the GK-1 was low but I didn't understand that it was the potentially very high Zout of some tube preamps that you were referring to, when you said "when the source has poor drive".

So I can stop worrying!  :thumb:

Regards,

Andy

PS: Yes, you might've tested the GK-1 with 'expensive' vs. 'cheap' interconnects but had you ever tested one with 11m interconnects - ie. say 1100pF? (My own ICs are about half that.)

andyr

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #230 on: 20 Apr 2009, 10:09 am »
For my cables (interconnects & speaker cable) I use Belden 89259.
The speaker cables are cross-connected twisted pairs, soldered directly to the drivers, with Kimber spades on the amplifier side.

-West

Hi West,

I wouldn't actually call JR's cross-connected speaker cables "twisted pairs" as they use 2 lengths of coax?

If you look on Hugh's site, here:
http://www.aksaonline.com/discussion/discussion_papers_connect.html

(and scroll down to my variant, at the end of the article) you can find a (IMO!  :lol: ) sonically better version ... as it uses all solid wire - no stranded!  :o

Currently I'm ... building a new turntable (with new MC headamp).

-West

I do hope you're using Hugh's "Paris" MC headamp?  Otherwise you won't get the optimal sound!  :thumb:

Regards,

Andy

grenamc

  • Jr. Member
  • Posts: 71
Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #231 on: 20 Apr 2009, 02:54 pm »
I would like to revive this post, for complete, unashamed personal gain.

I have just put my ASKA55 back into my system, after using an LM3886 based chip amp, and can appreciate the quality of Hughs AKSA amps, for a start the AKSA is not thrown by the unusual characteristics of my LITZ cables - the chipamp gave me almost 2v of dc ofset because of my cables.

I would like recommendations for the best cables to use with my Orions and AKSAs - what do other users with similar systems use?

Brad

Thanks Brad for reviving this thread.  I ordered my plans and ASP a couple weeks ago and the plans shipped yesterday, so I am pretty excited about building my Orions.  By bumping this thread you have given me exposure to Aksa amps and a few ASP tweaks.  I will admit, I have no plan to build amps or tweak anything for a little while.  In fact I bought a couple Adcom 2535 amps knowing full well they would not be my long-term solution.  :D  I know that a few months down the road I will definitely be in the stage where playing around will seem like the thing to do.  The ASP power supply certainly has my interest piqued, as does the GK-1.  On the GK-1 front, is that effectively considered a passive pre?  I am looking at possibly doing a Pass B-1 Buffer, so the GK-1 might make interesting competition.

-Michael

andyr

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #232 on: 20 Apr 2009, 11:06 pm »

On the GK-1 front, is that effectively considered a passive pre?

-Michael

No, the GK-1 is a real pre!  :lol:

Have a look here:
http://www.aksaonline.com/products/products.html

... and scroll down to "GK-1 Preamplifier".

Regards,

Andy

whubbard

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #233 on: 20 Apr 2009, 11:35 pm »
I wouldn't actually call JR's cross-connected speaker cables "twisted pairs" as they use 2 lengths of coax?

If you look on Hugh's site, here:
http://www.aksaonline.com/discussion/discussion_papers_connect.html

(and scroll down to my variant, at the end of the article) you can find a (IMO!  :lol: ) sonically better version ... as it uses all solid wire - no stranded!  :o

Andy,
Like I've said, I'm very happy with my cables, but then again, I might just have to try out your recipe in the future.
Thanks for the link too, I hadn't seen that section of website.

I do hope you're using Hugh's "Paris" MC headamp?  Otherwise you won't get the optimal sound!  :thumb:

I wouldn't have it any other way  :thumb:

-West

PSP

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #234 on: 22 Apr 2009, 02:17 am »
Hi Brad,
I concur that wire is generally the least of your worries, but--when I have tweaked everything else--I will definitely work on the wire to see how much more I can squeeze out of my system.

One exception:  I've followed AndyR's suggestion to use Belden 3079A ( I think that's the number... my internet connection is shaky tonight so I don't want to take the time to search and check)... this is two solid 22ga copper conductors, twisted with PE insulation, and shielded.  It's good because the capacitance is very low and I have long IC runs from my GK-1 to the two "monoblock" ASPs I have feeding the "monoblock" LF and AKSA amps I have behind each Orion.  The GK-1 to ASP interconnects are approx 10 feet long so low capacitance, shielding, reasonably small guage, and solid copper are all attractive. 

The other ICs in my system are VenHaus Pulsar coax with copper Eichmans on each end.  I also use BNC-Pulsar-copper Eichman as a digital interconnect from my (cheap) Denon DVD player to the Audiosector DAC.

Speaker Wire:  tweeters are 18awg twisted solid copper, teflon insulated from Michael Percy ($0.75/foot), Bass is Canare 4S11 star quad, and the mids are Belden 12ga from Blue Jeans Cable.  I think these cable choices are reasonable, but probably suboptimal.  Someday I will work on each one of these cables, but right now I have other priorities that probably have 20x the sonic impact that wire could have.

So far, the biggest hits have been:
 - using 25w LifeForce amsp (Platinum mods) on the tweeters
 - 55w LifeForce amps on the mids (Platinum mods, but for the midrange I liked Mundorf Silver/Oil input caps better than Sonicap Platinums... but on the tweeter amps I prefered the Sonicap Platinums)
 - Platinum mods on the GK-1... I still have to put in the GK-1 C4 and C7 "group buy" parts.
 - Hugh designed a power supply for SL's ASP that--in my view--had a major positive impact on my enjoyment of the Orions.  This is a definite plus if you can sweet talk Hugh into putting one together for you.
 - I'm very intriqued by Steve's description of the Master Set approach to speaker positioning... I will definitely give that a spin.
 
When I get all of that stuff done (and 3x more that I haven't taken the time to describe), I'll work on the wire.
   
Good luck, it's quite a journey.
Peter

andyr

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #235 on: 22 Apr 2009, 02:26 am »

So far, the biggest hits have been:
 - using 25w LifeForce amsp (Platinum mods) on the tweeters
 - 55w LifeForce amps on the mids (Platinum mods, but for the midrange I liked Mundorf Silver/Oil input caps better than Sonicap Platinums... but on the tweeter amps I prefered the Sonicap Platinums)
 - Platinum mods on the GK-1... I still have to put in the GK-1 C4 and C7 "group buy" parts.
 
Peter


Hi Peter,

OK you preferred:
* Sonicap Platinums on the input of the 25w Lifeforce for the tweeters
but
* Mundorf Silver/Oil input caps for the 55w Flieforce on the mids

... what about on your LF100s powering the woofers?

I ask because I've still got to do that mod - putting the Sonicaps and the group buy caps into the GK-1 is the next thing on my list!  :D

Regards,

Andy

PSP

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #236 on: 22 Apr 2009, 03:37 am »
Andy,
I still have 4 x 100N+ AKSA amps on the woofers, and may leave it that way for quite some time.  Honestly, it's been so long since I opened up the bass amp enclosures I'm not certain which input caps I'm using there (and, being 300 miles away from home, I can't just grab a scewdriver and have a look).

I began with LF on the tweeters and 55N+ on the mids. The midrange (~100Hz to 1400Hz) should not (I thought) be particularly sensitive to the amplifier chosen, so AKSA 55 should be perfectly adequate, I thought.  Well, I also had a LF55 on my bedroom system (preamp = TLP-N+, speakers are GR-Research Paradox 3) and one day I tried the LF55 on the Orion midrange, and OMG the difference was huge.  The LF on the midrange brought more immediacy, richness, and excitement to the music.  I was flabergasted, to say the least.  Later, on a whim, I tried the Mundorfs in that LF amp, and that was a big improvement (to my ears, at least) too. 

When i ran the Orion midrange with the AKSA 55N+, I could hear all of the notes, but midrange somehow sounded excessively smooth, lacking texture and richness.  This made no scientific sense to me, because the Orion XO (the ASP) should direct all of the high frequency info to the tweeters, where I had a LF55 (and eventually a LF25, platinum mods).  So, intellectually it made no sense to think about "texture" from the midrange... how much "texture" are you gonna get between 100-1400Hz???  Still, when I put the LF55 into the midrange slot, then used a Mundorf S/O input cap in that amp, those changes each made huge improvements in the Orion midrange... in my room, etc.   I make a living doing science, but sometimes these intellectual arguments that use "should" a lot fall flat in the face of experiment... as happened in my experience with the Orion midrange amp.

Based on my very limited experience, if I had to pick one input cap for use in LF or AKSA amps I would use Mundorf Silver/Oil because I would rather err slightly on the side of sweet detail and sexy midrange vs. neutral maybe slightly edgy detail and neutral midrange (Sonicap).  And, one can skip the input caps altogether if the upstream component has a good output cap (if you're OK with unprotected electronic sex).

That's all for now... time to get some sleep.

Peter



AKSA

Re: SL Orion XO and Power Supply Mods, & multi-amping
« Reply #237 on: 22 Apr 2009, 04:55 am »
Thanks Peter,

Beautifully presented and reasoned.....  I really enjoyed it!

You'd be wryly amused that about a month ago I bought 20 x 0,47uF Mundorf Silver/oils for the Soraya, having used Sonicaps before and been left slightly unsatisfied.  Now I'm a happy camper = same experience you've had.

Cheers,

Hugh