Mac MA 6100 worth the $$ to update? orig owner

My current sys:
McIntosh MA 6100 new 1975
McIntosh MR 78
B&W Matrix 1 Digital Monitors
Kenwood KD 500 w/Denon DL-301 II
Musical pref: Vinyl - Jazz, Classical 3%cd

I will be auditioning B&W Preference 6 speakers next wk
Your amp is rated at 70 watts into 8 ohms. A little on the lean side for me. How easy are the newer B&W to drive in your space compared to your present speakers? I have owned a couple of these amps and I think the newer Mac's are better sounding to my ears. If yours is in good shape and you have the manual and original shipping box, it is still worth some OK $. You would like the 6600 much better. Just my 2 cents.
Like anything, it's a more a matter of how much you love the sound of the MA6100. Audio Classics in Vestal NY can give you an idea of refurbish vs. upgrade cost options.

FWIW, B&Ws are power hungry, so you might want to consider trading up to a more powerful unit. You will get a better signal-to-noise ratio and pick up some depth.

Good luck & happy listening!
No ..Not worth it. And I am a Mac guy. You would do MUCH better investing in some new electronics.Sell the the Mac 6100 or use it in a 2nd system.While this is a great unit and built like a tank.It suffers from old solid state electronics and you can do a lot better in todays used market.Try a Tube integrated or a Hybrid tube/solid state integrated amp. You will be amazed at the sound you can achieve if you pair those B&W's up with the right amp. Happy hunting.
Also, I would check on that DL-103 with the tonearm you are using. This cartridge works with heavy arms like the ones used by old DJ record stations. And I am not sure if it is a good fit for the table/tonearm you are using. The DL103 has a comliance of 25. I strongly suggest you try a different cartridge like a Ortofon red or blue or a Shure. Something with around 10 compliance would be a world of difference for a medium sized tonearm. Do you notice your speaker woofers pumping in and out way too much when you spin vinyl?? This is a great indication of a mismatch with cart/tonearm.
Thanks for the advice, I have learned some things. I am using the SME type III tonearm and the Denon AU - 320 cartridge transformer(forgot to mention it). Per your suggestion, I checked the woofers while playing a vinyl record, the bass was prominent, woofers well behaved. Mattmiller, you stated a comliance (sic) of 25. My specs for the DL 301 II read Compliance: dynamic 13 x 10-3m/N. I feel I should know more than this but do not. I will take yours and Effischer's advice re the upgrade to a new amp. Exciting, actually.
Should I resolve the electronics and possibly cartdidge issue before deciding on the speakers. Note that I am to audition the B&W preference 6 speakers this week.
Your input is very much apperciated
Your Mac will sound significantly better with a full refurbishing; new caps and parts, not merely a cleaning and calibration. I have some 70's Mac, Yamaha and Luxman that was refurbed and I love using them. But I agree that in pure sonic terms it is not worth the cost. But if you love your Mac and want to enjoy it for another 20 years...
Thank you, Jihley. I am now looking at the MA 6600. I am prepared to replace the amp and speakers and the cartridge (which was purchased last) though I probably don't have 10 hours on it. What is recommended, replace speakers or amp first? At my age, I can afford the $$ but I'm sure my hearing isn't what it was.
Thanks for your time.
Transducers make a bigger overall difference to your sound, so speakers and cartridges should get first consideration. However, you will find that new speakers reveal other system flaws. Be prepared to start hunting for a new cartridge, tonearm and/or table if you do speakers and the integrated together. Also, consider the MA6700 instead of the 6600 - it will get you a MC input and going to moving coil would be a huge step up in image and depth that any B&W will easily reveal.

Above all, have fun and buy only what you like.
Thank you, Effischer, I've got some work to do, considerations to make. I think some of this research and information may look good on paper but may not sound good in my room. Yours and others who took their time to offer information is greatly appreciated.
For your information I am auditioning the B&W Preference 6 speakers. More fidelity, presence than my B&W Martix 1. The bass is tight and not so pronounced, similar to the pair I currently own. Perhaps as I have heard in the answers to this thread, 70 wpc may be a little light for the B&W. But the Preference 6 is an improvement over what I own.
This is a great forum and you experienced members are generous with your time.