Responses from mesch

Early Merlin Speakers
I became familiar with the Merlin Soeakers in the mid 80s. I currently have a pair of the 1Bs which still sound good. The foam wrap surround has deteriorated . I plan on covering with a finish burlap type fabric.    
How good is to use integrated amp as preamp with the preout feature
Given the Accuphase  has gain settings you can find a level of gain that matches well with the preamp stage of your integrated. I also believe the Accuphase should prove to be an upgrade.  Much will depend on how the Accuphase mates with your spea... 
Giving Advice without recommending your own equipment
@hickamore  Let me be the 3rd (I believe) to credit you for an excellent response.  
Tube amps under $7500
+++1 I own the Aric Audio Super preamp and Transcend amplifier. I encourage you to talk to Aric Kimball.   
How good is to use integrated amp as preamp with the preout feature
The best thing to do is to try. You wont hurt anything. Be sure to have volume down when swapping use of amplifiers.  There are always gain issues. With some preamp/amp combinations there can be too much gain with the result the volume control has... 
(Jolida) Black Ice Audio Foz SS-X Sound Enhancement
Great thread. May have to try the FOZ.  I will call Black Ice, they are good people, once owned a Jolida Fusion preamp, a great product for the money. I recently purchased a pair of the Apos Ray 12au7s for my Rogue Audio Sphinx V3 to replace the s... 
Looking for recommendations for integrated with a more “organic” sound.
Though I did not see to respond to your original post. Thanks for getting back. Many do not. Given your desires and price range the Sudgen 21 suggestions seemed to me quite appropriate.  You made a great purchase.   
Looking for an HDMI cable
@vthokie83 Thanks for the recommendations. The Supra cable is under consideration once I move towards I2S.   
Anyone ever have, use or hear this tube?
@buellrider97 Will do! It may be a while as I have not received them yet and am leaving town tomorrow for a week.   
Seeking Bookshelf Recommendations
Given your quest, I support the Fritz recommendations. I use both the LRS+ and Fritz Carbon 7SEs in my 11x15' room. You would need different amplification for the LRS+s.  
Devore 093 compared to o96
Room size needs to be considered.   
How you know your system is improving?
Generally I change one item at a time. I have several tracks that I am very familiar with that I listen to after the change. If the piece is new one has to consider the break in aspect. That said, if the upgrade has true merit the improvement pres... 
Cool running, low powered power amp
+1 @fthompson251 I would talk to Aric of Aric Audio about his tube amps. He makes a couple SET amplifiers.   
Looking for an HDMI cable
@soix  Funny you should say that. Shortly after my last post I had similar thoughts. I often recommend Monoprice to my non audio hobby friends and thought I should try a less expensive cable to determine the benefits of I2S for myself prior to try... 
Anyone ever have, use or hear this tube?
@andynotadam  I just ordered a matched pair of the Apos Ray 12au7s Will try them out in my Rogue Sphinx V3.  Was thinking of trying the Mullard 4003s as well. Not interested in the expense of NOS for this amplifier. Thanks for the rec.