I seem to find the happiness I seek
 

The first posts I made (MC 275 club page 35) described a comparison of MC 275's with an ARC VT 100 II, with a nod to paired MC 275's. This may irritate some 275ers, but I have new amplification that is better. I am using a restored Mac 1700 to run the bass modules on VSA VR 4 jr.'s and a Mac 1500 on the mid/treble. The sound is really something special. I never felt the 275's to give the bass oomph I like, despite their overall excellence. The 1700 has been rebuilt with new electronics throughout and gives a bass performance that is terrific in that it has power, great detail, and correct timbre, especially noticeable in jazz with a lot of string bass. The tone color is especially right in all sorts of music. It meets my definition of good bass sound:

Warm but not muddy,
Deep but not thuddy.

The 1500 has not been restored electronically but looks new; indeed it is the only piece of equipment I have ever had in truly collector condition. Tube complement is terrific too: 4 Sylvania 7591s, Westinghouse and Telefunken drivers.
The 1500 brings out an extended and sweet treble in a very real sounding sound-stage, with excellent (but not absurd and unreal) imaging, while the 1700 matches it in every way, with interaction between the two so good there is no disconnect in the sound quality or character (which one might expect in two amps from the same manufacturer and vintage.)
I use the 1700 alone when listening to FM, TV, or movies by using the jumpers on the VR 4s.
An ARC SP 8 drives the 1500 via the usual outputs, while the line out drives the 1700. The 1700 volume control makes for a handy tone control for the bass on bass-shy material, especially classical recordings. My hi-output Benz glider gives plenty of gain for the 1700 using the line out connection. The MC 275s are terrific, but in a system that can be easily bi-amped like mine, the flexibility in amping is really a plus. I couldn't be more pleased.

LowIQ.......Very interesting. That is the first time I have ever heard of someone using two vintage MAC receivers to bi-amp speakers.

I really enjoy the sound of my Mac 1700.
You should give the headphone out a try.

I agree it is rather unusual. I have a 2105 that I considered rebuilding after the 1700 turned out so well. The rebuild solved a muddy bass in the 1700 and I figured it would do the same for the 2105 (also a bit tubby in the bass), with my MR 71 serving for FM but I decided to save the money and bought the 1500 instead. It sounds so good that the 2105 and MR 71 are expendable now.
A question for you as a long time Mac contributor: would a rebuild of the 1500 with perhaps a bypass of the preamp section damage its value? It really is in collectible shape, but I can't help but think it would sound even better with such a bypass. I plan on doing the same with the 1700, but it's not in such high condition. Thanks for your advice.

I plan on getting h-phones this fall and look forward to hearing them as you suggest. Personally, I think these vintage Mac receivers with tube tuners are really under-rated. They sound terrific after the circuits are refreshed.

I agree, they are musical.The tuner does a good job of grabing signals too.

Nothing like a "fresh" (as in new/modern) set of caps to transform the sound of vintage gear. Probably get around to recapping my MA6850 at some point.

I have to ask... why did you pick the name LowIQ ?

Just a passing fancy.

I would aim higher. Like UltraHighIQ :)