Connections

It's because the XPS style power supply is multiple dual rail (+/-22, +/-10 and 2x+15) whereas the standard HiCap is two single rail +24V only; thus the output stages of something driven by an XPS have balanced power supplies.

Hungryhalibut,I am still using the stock cable that came with it,is there a big jump in sound quality by adding the Superlumina?First I will obviously add a power supply,but i am just wondering how much better it can get,say in comparison to when you added the xpsdr?Or did you do both at once?

I have the same setup and can speak to the results, the Super Lumina din to XLR in this particular arrangement is big medicine.  I can't, however, speak to the technical details.  Is the 272 acting as a true bypass between the XPS and 250 so to speak, with SL getting to work a solo path....?

It's probably not worth going to the effort of ensurining the ground reference point is in the power supply when it comes to the 272, the digital circuitry will screw things up anyway.

fatcat posted:

It's probably not worth going to the effort of ensurining the ground reference point is in the power supply when it comes to the 272, the digital circuitry will screw things up anyway.

I think Naim's internal power & 0V distribution system within the boxes is a little better than that, please give them some credit for design competence!

Huge posted:

It's because the XPS style power supply is multiple dual rail (+/-22, +/-10 and 2x+15) whereas the standard HiCap is two single rail +24V only; thus the output stages of something driven by an XPS have balanced power supplies.

I don't really follow that, but is that why the earth can connect directly between the two boxes, whereas with a Hicap you shouldn't do it?

I can confirm two things:  1.  yes too much time off work = too much idle thinkings time   2. yes your theory has some credibility.  I've experimented with pre-pwr signal paths albeit between Supernait sections. Huge has done the same (forum rules don't allow discussion)  but the difference is very small.  Then due to moving boxes around & needing more cable length I have gone back to stnd Naim method.

Incidentally,  going slightly off topic,  I tried an SL IC a few weeks ago,  it didn't do much over my own cable & I felt a little disappointed in some respects,  then I tried a Lavender,  then back to my own;  OK I'm content & can now read the forum notes on that subject with some better understanding.   

OK, the theory works like this...

1  Voltage Regulators.  Voltage regulators are never perfect (i.e. they have an output impedance).  Variances is mains voltage result in (smaller) variances in rail voltage.  If you have a single +ve rail supplying an amplifier it's PSRR* is, at best 50%, if you have a dual rail (+/-) supply to an amplifier it's PSRR can approach 0%.

2 Cable lengths.  The longer a cable is the greater the voltage drop across it (all other things being equal).
So is a amplifier has a single rail supply, supplied down a cable, the amps full current runs in the return core (0V) of the cable as well as the power core cable.  Thus the reference voltage (0V) varies with the current draw of the amplifier.
If on the other hand the amp has dual (+/-) rail supply, only the signal return current flows in the reference (0V) core of the cable.

Hence the different 0V reference schemes

PSRR = Power Supply Rejection Ratio.

Hungryhalibut posted:

I don't really follow that, but is that why the earth can connect directly between the two boxes, whereas with a Hicap you shouldn't do it?

If I understand your question:  Hicap is the 0v star (single) ground point for pre-pwr signal path,  but its not earth connected.      The XPS 0v is not signal & is the common 0v for the 22v 15v & 10v power supplies.    That same 0v is connected with the 272 signal 0v & depending on the earth/ground lift switch (chassis/float) determines the single signal 0v (earth / ground)

Mike-B posted:

I can confirm two things:  1.  yes too much time off work = too much idle thinkings time   2. yes your theory has some credibility.  I've experimented with pre-pwr signal paths albeit between Supernait sections. Huge has done the same (forum rules don't allow discussion)  but the difference is very small.  Then due to moving boxes around & needing more cable length I have gone back to stnd Naim method.

Incidentally,  going slightly off topic,  I tried an SL IC a few weeks ago,  it didn't do much over my own cable & I felt a little disappointed in some respects,  then I tried a Lavender,  then back to my own;  OK I'm content & can now read the forum notes on that subject with some better understanding.   

First off, I'm not an Engineer, and don't fully understand the theory behind Voltage regulators, and the earthing arrangements.

That being said, I agree, to much time off work, and SOME credibility to HH's theory.

 Posted by HH:

"Now, the ADVANTAGE of the 272 way is that you can use a SuperLumina lead between the 272 and a 250 or 300. If you have a 282, say, you can add an SL lead between the Hicap or Supercap, but the signal is still going down ye OLDE SNAIC from the preamp to its power supply. Maybe this means that the SL din to XLR upgrade is more effective on the 272, because it improves to complete pre to power interconnect chain."

This wouldn't be the same olde snaic that connects an 552PS to an 552 Pre-Amp ?

As to your slightly off topic remark, experimenting with SL IC:

That's what we do!

Spend thousands of dollars for minute improvements, that aren't detectable by the Norm.

 But again, we aren't the Norm! LOL....

Trust your ears, and enjoy your Music!

JMHO.

Allante93!

HH - I've thought about this.  Does the SNAIC strangle things.  Doesn't sound like it.

The Strat (Fender) posted:

Does the SNAIC strangle things.  Doesn't sound like it.

Much better to have a burndy thingy going to the 552PS imho 

The Strat (Fender) posted:

HH - I've thought about this.  Does the SNAIC strangle things.  Doesn't sound like it.

No, it's not a constrictor! 

"'RICHARD DANEADMINISTRATOR

9/9/16 11:41 AM

Non-Naim interconnects, speaker cables etc.. no problem.  However SNAICs and Burndys carry DC power between kit and getting this even a little bit wrong means, at best, compromised performance, and at worst, potentially catastrophic consequences.  Naim's view is that using anything other than Naim built SNAICs and Burndys constitutes an unauthorised modification and puts your system at potential risk.""

That was an entertaining post!

Perhaps the only Reptile that can adapt to the Naim's ecosystem, is the King Snaic.

That being said, the Reptiles that belong to the SL Family, can only perform at it's best in a familiar environment.

 That being the Full Loom! 

Their lies the ADVANTAGE of the 272 $$$!

Loom River, drifting from Statement Hills!

Just some pass Thoughts.

Allante93!

Hungryhalibut 

Maybe being off work sick has given me too much time to think.....

Think you answered your own question