Full Range comparison

Look I am trying to take all newbiews and the old timers, up to CLASS A. have you ever heard of 

~~~~DISCRETE OPAMPS~~~~
No? 
Well neither have thousands of others..I JUST TODAY made the discovery, 
You need to go count all the 2 cent opamps in your CD player, takea  pic, with #'s to 
~~~SPARKOLABS~~~~
He will match it up to his inventory,,either singles or better duals.
I have just order 6 singles for my state of the art 
~~~CLASS A~~~~
Cayin 17, made 2003...Mark 1,,,the new Cayin 17 Mark 2 is out, sells for just a  few bucks over what I paid. 
Built like all Cayin, has dual top line of the line trans. 
Weighs a  hefty 20+ lbs. = a  beast.
With new opamps, + new Mundorf;'s = class a

I have had some experience with FR designs, and many have a lot to offer. Most however have a shout in the midrange at about 1K that I cannot listen to! Round and round I went to find a driver that satisfied my preferences. The Mark Audio came very close with the 10P model, but I wanted more bass. This driver was used in a small back loaded horn design. I want to build another in the future but with the 12P driver instead, and in a larger cabinet.
 Audio Nirvana drivers (the classic series, w/o whizzer cones and alnico magnets) have a good overall sound including bass, but are slightly recessed in the upper midrange.
 I have also tried an interesting design by Deware audio that uses a unique open baffle design with a Hemholtz resonator for the lower cabinet. Truly, the choice of drivers matter here. The FRX2 drivers sold by Decware are great sounding, BUT just know that they are voiced for tube application. Their prices may stop you in your tracks at 600 ea. too. These drivers are quite unique themselves by using a special transformer to deal with the shout issue, and to tame some of the phase response anomalies of this driver.

If it’s not too late. I’m a Mark Audio FR fan. In fact, I’ve not built with much else.  I made some monitors using a vented box and some 7MS (metal cone) drivers. These are used every day in my son’s studio - but they do need a sub really.   Then I built Woden Design’s Avebury using Mark Audio 12ps. These sound fabulous to me. Truly full range, wonderful easy room-filling sound yet great precision too. So easy to set up. In my room I need to control some of the bass using Roon’s DSP.   Next project is a 2x9 driver line array...  The great thing about self build using FR drivers is the simplicity and the resulting sound value for money.