It took me a couple of days after I joined CS to discover the mods available and who might be able to do them (not me) lol. So right away I got a message from Russ and made arrangements with him for my amps. I will be shipping him both of my M1.0 amps next week. I should have them back by the end of April and I can't wait to hear the magic! I also learned about the C1 mod and did a little digging to find this legendary BillD I had been reading so many great things about and the fantastic work he had been doing. Sadly I soon learned of his illness and them immediately thereafter his passing. It's weird that I feel a genuine sense of loss for a man I never met or had any contact with. My heart goes out to his family and all his friends, of which there seem to be many.
Now I will be looking to see who else might be able to carry on the good work of BillD and mod my C1 so it can keep up with my rehabilitated amps. As for the TX-11a tuner goes, I saw a blurb on a post from a member at CS about a mod he called "The James Van Dyke mod" that had been done on his tuner by RichP. I'm not sure what all is involved in the mod or the improvement and benefits it's seeking, but I suspect it includes extensive replacement of aging caps like the other mods. I will keep digging to learn more and will let you know what I find out if you are interested.
To your question about speakers I have almost too many, but like the rest of my treasured analog audio gear, all the speakers I own are from the 80's or earlier. My favorites right now are an upgraded pair of DQ-10 by Dahlquist. They are great sounding speakers to my ears and seem to work well on every amp I have tried with them (Hafler SE120, Pioneer A-717, JVC RX-D302 & RX-D702 receivers and even a low power home-made push-pull tube amp based on an ancient chassis of unknown origin). Now I use them on a system I set up with a Nikko Betta II pre that has tubes in the path before and after it (Bellari VP129 single tube phono pre and upgraded Dyanco 70 tube power amp). The results are warm and sweet. Other notable speakers in the rotation include JBL L80, Boston A400, Magnapan 2.5 RT supplemented with a Cerwin Vega HT-12PWR sub and. Some samll speakers I use in the bedroom & shop are KEF C35 and JBL Pro III (I have two pair of these and use the others for rear surround speakers with a JBL LC1 center speaker). Other not so notable speakers include a pair of DCM TimeFrame TS600 and a JBL SB-5 sub. A few of the very cool ols speakers I'm proud of are the NiViCo (JVC) 5340' with horns, and Sansui SP-3000 with very nice cabinets and beautiful wood lattice (komiko) grills. I also have several other pairs of speakers stacked along a wall in my garage that are buried behind boxes and can't get to. A few are home-made that I bought for the drivers but a few are vintage and unusual so I got them because I thought they were cool.
For the Carver stack I will be checking out my collection of Infinity Quantum series speakers. I have working pairs of Qb (with the cool Infinity stands) and Q2. I also have an unusual pair if QJr that need some work (they also have the cool Infinity stands). I bought them new when I was stationed in Germany and they are a bit of an enigma because unlike all the pictures I have seen of the QJr with the black painted face and close fitting grills, mine have the wood veneer faces and stand-off grills like the Q5 and also have the Watkins Dual voice coil woofers (I checked the connectors) like the Q5. Even though the box and crossover are labled QJr, they appear to me to be Q5's (very odd). I bought a pair of Q5 crossovers on ebay to plug in the extra connectors on the Watins woofers to complete them as Q5's. My real pride will come from hooking my Carver M1.0 amps to a pair of QLS monsters that I'm working to restore. They should be ready sometime this year and I can't wait to hear what they will sound like with the Carvers.
Sometimes I think I may be missing something by not having a more modern pair of high-end speakers and I'm looking for suggestions on worthy speakers to audition (that don't cost more than my car). lol