I would sooner trust period-written factory literature than what some young whippersnapper who probably never set eyes upon, let alone owned an MX110 nor experimented with a variety of McIntosh amplifiers from widely varying eras- on the strength he happens to work at McIntosh. I have.
The problem with McIntosh's 1960 owner's manual is that it doesn't list the output impedance specifications of the MX110. We don't know if the 100K amp input impedance recommendation in the owner's manual was based on a specific ratio of 100:1, 50:1 or 10:1 etc.
...They recommend 100,000 ohm amplifier input for the They didn't pull these figures out of a hat.
Just seems silly to obsess over what the precise measurements are when the manufacturer has presumably done this in making the recommendations it does.
Steve Hoffman has nothing but praise for his MX110 which he has reported excellent results in a $100K system.
I measured the output impedance of my MX110 at 100 & 1,000Hz with volume control at 12:00, 1:30 (where I try to set up gain structure of system) and max. Bal @12:00 for all meas.
Findings:
3,700 ohm @ 12:00
5,800 ohm @ 1:30
~500 ohm @ full
No sig diff between 100 & 1,000Hz.
My conclusions:
1. MX110 will probably meet Mac’s performance specs driving loads >= 60,000 ohms.
2. Mac’s recommendation of 100,000 ohms was typically conservative.
3. MX110 can drive impedances lower than 60,000 ohms but will probably not meet Mac’s performance specs due in part to increasing influence of volume & balance control positions on output impedance.
Have never had any problems driving a SS amplifier with the MX110, it can drive most any load over 10K with no ill effects, at 600 ohms you will have some bottom end roll off.
Steve Hoffman said:I have a $190,000.00 playback system in my listening room (the gear is not mine, just a loan) and I've been listening a lot these past few days to all types of music.
I took my 1966 McIntosh MX-110 Z out of the cabinet in my vintage system downstairs and lugged it upstairs for a little test.
At any rate, in my system upstairs I am using the giant Venture Audio Grand Excellence III speakers, the amazing Tenor 350M monoblock OTL amps, the Concert Fidelity CF-080 linestage, the Modwright Sony 9100ES tubed Platinum Signature Truth digital player and the McIntosh MCD500 player, Kubala-Sosna bi-wire and FMS interconnects.
So, all I did was set the McIntosh MX-110, Panloc wood case and all on the top of my rack and carefully switched out the Concert Fidelity linestage and hooked the amps up to the MX-110 along with my Modwright disk player. I made no other changes to the system, just one preamp substituted for another preamp.
Holy cow, it sounded WONDERFUL on the MX-110. I mean spooky real. I was astounded at how good it sounded. The McIntosh was really holding it's own in the system.
I dropped this antique thing into the heart of a world class stereo system and the sound didn't go to hell, it stayed right up there in Groovyland. It will do the same for you if you have a modest system or a fancy shmancy system.
Having owned a number of MX110s over the years, I seem to be the only guy that thinks one can do much better for a preamp. The MX110 is firmly im my rearview. IMHO, it would be a real limiting factor in unlocking the performance an MC275 VI is capable of.
What aspects of the MX110 did you find subpar?
My biggest beef with the MX110 is that it sounds lean with the Loudness switched OUT and boomy with the Loudness switched IN.What aspects of the MX110 did you find subpar?
My biggest beef with the MX110 is that it sounds lean with the Loudness switched OUT and boomy with the Loudness switched IN.
My biggest beef with the MX110 is that it sounds lean with the Loudness switched OUT and boomy with the Loudness switched IN.
Obviously I’m not damacman but my $.02 regarding a few of MX110 weak points are:
1. Unbuffered outputs
2. Tone controls don’t produce flat response in 12:00 position and channels don’t track well
3. Volume control tracking is not so good ( meas unit has NOS control)
4. Not particularly quiet with many sources of extraneous noise injection. In my unit, the wire to “stereo” light was routed near volume control. This caused annoying low level buzz in output when tuner was in stereo mode and light was lit.
No question the 110 is a visually pretty unit with a nice feel to it. But it wasn’t TOTL when new and it certainly isn’t now. Just my opinion but a restored MC240 or other Mac amp of the era far outperforms the 110 relatively speaking.