Distortion with ARC Ref 150 and Maggie 3.7


I have this problem that drive me nuts for quite a while. I purchased a like new fully balanced ARC Ref 150 tubes amp through Audiogon for my single ended only CAT SL1 Ultimate preamp and connected both with a RCA to XLR interconnect. It sounded okay with most recording but has awful distortion with certain recording specifically piano and vocal. Some of this recording happens almost on entire record but some only on certain musical passage. Most of the time with higher pitch or peak of music or higher volume.

For your information I listen to vinyl only most of the time and more on Jazz music. Other component listed as follow:

Turntable: Sota Nova, Tonearm: Origin Live Illustrious, Cartridge: Dynavector XV1-S, Step up transformer: Bob's Device CineMag 1131 (Blue) feeding directly to CAT's own phonostage, Speaker: Magneplanar Magnepan 3.7. Power cords, ICs, Speaker cable, Autoformer: Paul Speltz Anti-Cable.

Trouble shooting which has been done includes: checking preamp tubes condition and checking power amp bias. Since ARC claims their Ref 150 was design for balanced preamp only so I also tested by replacing it with single ended tubes amp but the distortion remain. As for the cartridge I believe I have done the alignment pretty accurate with the Mint's Best Tractor but not very sure with the azimuth.

While tested with my other 2 pair of speakers, one which has higher spec show the same problem while the lower spec one seems get rid of distortion. So I suspected the issue probably was with the new Maggie. Called the dealer and he performed a test with his transistor amp with no distortion at all. So he assumed my Maggie is okay. Is it true that the Maggie only good with transistor amps?

By now it leaves me with total confusion! Sincerely hope fellow audiophile here could give me some advice and save me from this endless misery !

Thanks very much in advance!
pakwong
Pakwong,

You're a hobbyist and - if you're willing and able to bite the bullet financially - you might want to consider building two systems. I was in your position and kept both my Juole preamp and my ARC power amp even tho they weren't well suited for use together. I added the ARC line stage and Cary power amps to form two very different systems.

You ask which alternative A'gon posters here might recommend and I'd say that it's really such a matter of personal taste that recommendations wouldn't be very useful, so.... you could build two systems to compare them. If you see the value in each and can afford it, enjoy both. If you prefer one over the other, sell the electronics that come up short.

If you don't want to (or can't) pay for this option, you might try to borrow suitable partnering electronics for each component from a local B&M dealer (if one is available to you) for audition and keep the system that you prefer.

Owning two electronics chains may be expensive, and it may not be a rational decision, but who ever said audiophiles are rational?
"If you were me, which do you prefer?"

Good question! Both are really fine options.

I really like the idea of trying the Jensen transformer as a stop-gap. Jensen makes really good transformers and this option might work sonically. Might.

If forced to choose one option over the other, I'd go the CAT route because the JL5 would, I feel, do a better job of driving your Maggies. It's not about watts. CAT amps are designed to drive pretty much anything.
Martykl, if I have more than one listening room, I would have keep both! But I still think we audiophile should try to be rational as best as we can lol. The more I went deep into this hobby, the more I realized that we have to put a lot of effort to build a real good sounding system. Two or more system might be overburden to me!

Regards,
Yes kevin, I try to keep rational thinking and focus on the Jensen transformer first.

A friend of mine also recommended JL 5. Although only rated 100 watts and have 8 KT120 power tubes just like the Ref 150, people who have been with CAT still think the JL 5 would be an all round winner. Only when think of the 100 watts JL 5 driving the Maggies which has been known to be extremely power hungry, it's normal for a audiophile to try to think "rational" lol