How important is a Linear Power Supply Versus a Switcyed one?

That's what I am afraid of....  a teeny bit. I don't consider myself a tweaker and generally don't do things like aftermarket tonearm counterweights, cable stands so they don't touch the floor or that type of stuff. I do care very much about quality and was very pleasantly surprised by a tonearm I bought last year that blew me away (the phono stage made almost the same difference) but a 2 step turntable trade in/upgrade that cost more than the arm made only a very subtle difference and I was disappointed with that, but liked a couple new features so I kept it.  

I am very much aware of the law of diminishing returns and I think I am at the point where my strategy of paying up to $1000 for something noticeable being a no brainer is now impossible. Maybe I am wrong here. I think I am going to call Ron Sutherland - he is a very nice down to earth guy.

I have always found a linear power to be an improvement over a switching power supply.  This is both in analog sources/preamp as well as digital transport sources.  If your system is very warm and laid back, you may not notice any difference.  I think your Plinius integrated is going to be a much higher resolution and revealing amp.  Upgrading your phono stage to linear power supply will likely remove some glare from the sound and give you a smoother and more realistic sound.  I took a look at the Sutherland Insight phono stage.  The power supply is a separate board that can easily be taken out and replaced.  If you google for picture of "Sutherland Loco", you can see what the linear power supply board looks like.  They would use the same one in your Sutherland Insight phono stage.

I have always found a linear power to be an improvement over a switching power supply. This is both in analog sources/preamp as well as digital transport sources.

To give an idea here, there are some hi end manufacturers that offer a power supply upgrade they say is a considerable sound improvement, and that is to pay the extra $$ to get their "linear supply option" installed instead of the smp that come standard with the equipment.

I have yet to bench test any equipment that uses a SMP power supply that doesn’t show HF noise + artifacts infiltrating into the circuit and from the output. Not as low noise as I’ve seen from a good linear supplies.

You’ll get the idea of the HF noise with artifacts if you go near a smp power supply with a portable am radio tuned around 600-700khz off station but (not muted) it’ll squeal it’s head off, and that the airborn radiated stuff, then there’s the stuff that’s going back into the house wiring.

Cheers George

Thanks for all the input.

I spoke with Ron Sutherland and he is the nicest guy. Can't believe he acts as his own distributor and handles inquiries directly.

He said others in the past who did the Insight upgrade were pleased, but he didn't say they were happy they did it and would do it again. He is not a salesman at all and said with or without it, I would be happy, but he knows it it technically better and like some of the posters have said there is some internal noise reduction. The question is, does it sound better to someone with very good, but not Absolute Sound ears.
 
It's an internal board which he said I could do myself, but you have to "jigger a couple things" and blindly thread an LED and it would take an hour (same price if he installs it or not, which was surprising). The second time I would do it would be easier/quicker.... I'm not really looking for a science project. Even though it's only spacers and screws and an LED (no soldering), he said you need to be dexterous.

By the time shipping back and forth is added, it's about $400, almost half of what I paid for the whole phono stage (used). It is a marketing strategy - he charges 25% of list for the linear Power Supply, which seems a bit much compared to the cost difference when manufacturing the LPS board versus the SMP one. I doubt the incremental cost to him is 25% more with the swap. On his 20/20 PS, which is also widely regarded as a great value, he charges $450 for an LPS and it comes in a separate box, so it is easy to compare.Thats a $2200 Phono Stage vs. $1400 for the Insight.

Doesn't matter though - if it is a noticeable improvement, I would do it.

I just don't know....if it was an external box it would be so much easier to compare and return if I wasn't happy.

Does anyone know anybody who has done the upgrade and saw a noticeable difference? I'm of the school that the most important part of the system is the source, so I don't mind spending $$ there.

The amplifiers I use to drive subwoofers are AB and have switching supplies. No transformers. They certainly have no trouble providing a lot of current on demand. For a Phono amp I don't see why not as long as it was well filtered. I'm not sure way the sound would change. If both supplies were well designed it shouldn't. The advantage of the switching supply is efficiency. Maybe it would be a good idea if you run your house on solar panels.