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

Showing 6 responses by daveyf

Pakwong, Congrats on the JL5. I think it will put the ARC to shame.Great amp and a perfect match for the CAT preamp.
I think the real problem here is as stated by several other posters...that is the incompatibility between the CAT and the ARC. I think ARC is simply trying to cater to fashion in regards to their seeming insistence on only using balanced inputs on their current gear. This fact has made me stay away from their gear and will continue to do so until they get the picture. I can see no reason why the extra electronics needed with the balanced option is at all necessary, except to add cost and to cater to as I stated earlier....'fashion'. Personally, I feel that single ended gear sounds better than balanced gear; IMO,unless one is using their gear in a VERY highly corrupted noise environment or with VERY long runs of cable, balanced is nothing but a joke in high-end.
My advice, dump the ARC Ref 150 and get a more suitable amp for the CAT...like maybe a CAT amp!
Ralph, IMO the loss potential generated by the additional electronics needed to go balanced in home electronics; is more of a problem than what one typically sees as noise infiltration into the system by outside sources. Unlike in the pro audio world, in home hi-fi, we're talking of cable runs of what...a few meters at most. In pro audio it may be 50-60'++ , then i can see the potential benefit. A cable that is effected by noise that is 6" in length must be a ****poor cable IMHO.
So Zd542, you want to expand on why you believe what i posted is incorrect.
I am all ears.
Ralph, that would seem to have been a smart thing to do. Pity other companies failed to see or take that path.