Traded Off my SLP-05

To @sqitis what brand/model 6SN7 tubes, and coupling capacitors did you have in your SLP-05?

If you tried 3 different SLP-05 preamplifiers and all of the tubes listed above, and it was still not "open" sounding enough for you, it's likely something else in the system going on or a combination of things together yielding a less open result. 

Your Plinius is known for a warm and open sound.  And, so are the Eggleston Andra speakers.  For example, If you had warmish caps in the SLP-05 too, that could make a difference even more to the warm side all three together.  

You also mention the "Tele" tube above which implies you are trying to open things up more there too.  All just guesses, but seems like a string of things together is not giving you the result you are looking for. Try the new pre and see if it's less rich and warm and more open and transparent for you.  Might work. Best of Luck.  

okay so we’ve kind of concluded the prior general direction of those components all together is a big warmish and veiled over result so to speak. Let’s assume that for now.Not bad, just not as opened as you’d like it to be with your prior speakers. What you shared makes sense btw. I’ve heard those speakers before, fyi.

So..., you’ll get your BHK preamp and as others suggested and you’ve summarized, maybe a Tele or Tele like tube will add some openness and detail.

Now the cable police will come shoot me but gotta ask. Have you been running interconnect cables at the source and between amp-to-preamp that are possibly masking/holding back the sound a little bit, by chance? i.e. I can swap out my own smoothed over pure copper interconnects for other interconnect pairs I have with tinned or silver-over-coper interconnects to add some air, openness, detail. What ya got going there for all interconnects starting with your source to preamp to amp(s)? How long are those interconnects in feet/meters?

@squitis - okay, imo I think either the Supra or Kimber Hero are just fine, and 1-2m length is good too. Did not mean to go down that rabbit hole, but good to know.

Back to the new preamp, how far out til you receive the BHK preamp?

+1 to what @ozzy shared.  

I've found there seems to be sort of this compounding effect when you have 3 components in the chain that are all soft, smooth, more laid back on the top end.   

If the speakers are slightly warm and veiled over, there might be other options.  If the new BHK preamp does not help, in parallel [worth researching this too] I'd be contacting the speaker manufacturer-designer to ask if there are potential crossover changes available to swap in a change.  They might have advice here too. Clearly the speakers are voiced in a specific way for a type of sound achieved.