Hi Rick,
I ran a very similar setup to yours back in the day.... but not with the M90. I used a Sharp GF-9292. At one point I had external speakers, turntable and a component cassette deck hooked up to it. Held me over quite well until I finally stepped up and got a proper integrated amp to run the show.
That was in 1981.
In the almost 30 years since then, I did a 4 year enlistment in the military (where I was able to buy gear at less than average prices) went to college and moved around quite a bit. It seems my mixture of components changed quite a bit over the past 30 years as I waited out better and better deals along the way. Thanks mostly to pawn shops, classified ads and more recently the internet.... my "this is where I go to loose my skull" sound system has evolved to this:
If you were to add up the MSRP list prices of everything you see in the pic above, we're probably looking at around $8~$9000 in total cost (that includes the Tannoy Proto-J speakers and an Akai R2R you cannot see, as well as the computer monitor and the Rane Serato box/interface). I would never be able to afford this system had I paid even close to list price. Truth be told, I have around $1500 invested in what you see in the picture, thanks to clever local and internet shopping, being in the right place at the right time, equipment trades, and generally lots of patience! There are several pieces shown that I even got for free from family members as they were downsizing (HiFi VHS & the CD-R) or friends who were going to throw things away (like the working Akai R2R). I have not factored in the money I lost on gear that I sold off along the way, but even with that I'm still way ahead of the game.
I was kind of reluctant to post because most of you have seen pics of my at-home DJ booth from other "show me" threads..., but getting to the point of this discussion, this is really a high-quality recording station just as much as it is a place for me to get my DJ fix. Thanks to the many inputs and outputs of the DJ mixer, and the Yamaha pre-amp, I can run a myriad of signal in a whole bunch of directions. If I"m recording from vinyl, I could conceivably do simultaneous recordings to two Nakamichi 3-head tape decks, a Phillips CD recorder, a Hifi VHS deck, the Akai reel to reel, and also straight into an AMD based 2.6ghz computer with a 10K rpm hard drive to save as MP3 or WAV file.
Obviously, I take my recordings and their sound quality quite seriously.
And, like my boomboxes, this is basically a savings account I can play with. If I had to liquidate, I would probably get more than double my investment back. Everything you see in the pics works 100% with no missing buttons or compromises.