Help in minimizing hiss

I’m thinking that if you have a pair of Legacy’s flagship 80K speakers with their Wavelet processor which in my experience is extremely quite your first step should be contacting Legacy. They can help you trouble shoot this issue better than a forum and without you going crazy trying a million things and getting frustrated.

@jsautter  Again I don't expect the tubes to quiet things down. I am rolling them for improved sonics.
I'm not sure there's much I can do to quiet down the Wavelet which seems to be making the lions share of the hiss.

Let us know how the tubes help, but my fear is that these old stock GEs will increase the noise and you may find new noises which didnt exist before. Hope I am wrong.

Turned on the Pass amps first and there was almost no audible noise with my ear on the tweets
Then I turned on the Wavelet and the hiss came back but not full volume
Then the Freya in full tube mode and the hiss got a bit louder but not much
Approximation:The Pass amps are less than 10% of the hissThe Wavelet is about 60% of itThe Freya (surprisingly) is only about 30% of the hiss
Thanks again for all the help guys, it's greatly appreciated.I can live with a bit of hiss that is inaudible from 3' + but just want to be sure I'm doing all I can to keep the signal path clean/clear.Scott

@erik_squires  I do have absorptive panels covering much of the wall behind the speakers and a 2'X4' treatment on sidewalls at first reflection points. Room is 18'X 34' with 19' ceilings.
@jsautter I'm only rolling tubes to replace the JJs that came with the Freya.
@lowrider57  Tube Depot set me up with low microphonic, matched etc GE 6SN7 GTAs. Should be here in a few days.

You should work with a reputable dealer and request low-noise and low microphonic matched tubes. The quality and noise level of a 6SN7 can vary greatly, but the right tube will provide wonderful sonics in a preamp.

I mentioned a power conditioner for your sources since noise from the AC line will also be audible thru your speakers. This is not hiss, but every line connected to the power grid will introduce noise into the system (even a dedicated line). 

I doubt that new tubes will help, but give it a try. You can do much better than the Freya but you will most likely have to spend more money. In my experience your cables will not help this problem one bit.

Since you already have  warm sounding Pass amp why not try the noiseless Benchmark LA4 preamp, 30 day free trial and $2500. 

https://benchmarkmedia.com/collections/preamplifiers

How are your room acoustics? Especially between and behind the speakers?

If not treated, experiment with some blankets.

This won't remove hiss, but is an area often neglected which raises the perception around those frequencies. :)

Power conditioning may help in lowering overall noise floor but it certainly won't address tube hiss.  A well designed circuit in your component coupled with low noise tubes can achieve really quiet operation.  I run 99dB efficient speakers through an integrated tube amp (max gain 34dB) and have zero audible noise and hiss even with my ear pressed to the grille.

 It's hard to be noise-free when using 101 dB sens. speakers. 
Did you try the suggested test of only having your amp powered up, no components?

If your amp is quiet, then your upstream devices might  benefit from power conditioning.

I'm also using a Schiit Freya, always through tube mode. It's the source of my hiss through Vandersteen 2Ce Sig IIs. I'm only aware of it when music is not playing and then only if I'm standing within 5 feet of the speakers.

I don't have an extra set of tubes to try but will be ordering Gold Lions today to try out.
Agreed that it's important to lower the noise floor as much as possible and the hiss, while faint, is audible.

I typically associate hiss with tubes and agree with others that The Freya is a likely culprit.  Have any spare tubes to try?  And I don't get the sarcasm on wanting to remove hiss or any other unwanted noise to lower noise floor.  It seems silly to promote using wonderful cables while dismissing hiss as somehow not degrading to overall SQ.  I've been much happier when reducing all noise in my system to the extent practicable.

@mihorn  I have tried a few different types of power cords from stock to Pangea and now Nordost. I don't hear an audible difference in hiss.
The hiss got substantially quieter when I pulled the Panamax power conditioner out of the system.

Thanks for the input all; sarcastic and otherwise. lol
Oddly, I think the Wavelet may be as noisy as the Schitt.Switching to passive mode doesn't quiet things up very much.
Will play around with it more the next few days.

If you suspect noise is coming from the Freya, change to passive mode which will remove any tube hiss.

Most likely the culprit is your Schiit Freya. Obviously your high efficiency speakers dont help this situation. If it is the Freya I doubt there is much you can do to remedy this situation. 

Some audiophiles think its all about being able to hear the music. But as we all know its really all about the hiss. As a great audiophile once said, "If you hear the hiss, you must dismiss."

If the hiss is due to an electronic component's noise floor, you cannot remove or negate it short of getting new electronics with a lower noise floor. Alternatively raising the signal-to-noise but that becomes difficult with your 101dB speakers.

A ground loop is different, and may be addressed by addressing how the gear is grounded and plugged in to power.

Simplest thing to start with is to have only the amp and speakers connected and powered on, and then add components backwards to identify at what point you first hear the hiss.