2. amps-preamps
  3. 1407646817

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 knghifi

knghifi
1,668 posts
 
Minorl +1
knghifi
1,668 posts
 
10-04-14: Pakwong
The fact is, though having trouble with the Ref 150, I'd still recognized it as a great amp after solving the matching problem with the CAT preamp. But as recommended by some of you here, I feels that the Ref 150 would be better matched with a true balanced preamp as the design concept suggested, in order to achieve the amp's full potential. If the new ARC preamp has build in phono stage like the good old days, I would have gone the ARC path!
You should do your homework before and NOT after the purchase.

CAT makes great amps so you will be happy but it doesn't sound like ARC. They are different and not superior to the other. GL!
knghifi
1,668 posts
 
10-04-14: Onhwy61
In a free society a person should be able to do his homework whenever he wants to and it's nobody's business but his own.
Are you serious? You have issues with my suggestion?

I could care less what Pakwong does with his $$ and problems. This is an open forum and I'm contributing my .02.

As others have pointed out, it's questionable why ARC makes amplifiers that cannot operate correctly with single-ended sources.
Because it wants to?? In a free society a company should be able to produce whatever it wants. They stay in business if there are demands, otherwise bye bye.

Also in a free society a person can buy whatever they want. If they don't like ARC's approach, don't buy it. Again, if you do your homework pre-purchase, it will save some headaches.
knghifi
1,668 posts
 
Almarg, until Minorl post, I felt tone of the thread was blaming and questioning ARC design which was unfair IMO.

So I want to make a GENERAL SUGGESTION best do pre-purchase homework to avoid compatibility issues post purchase so I guess it applies to both Pakwong ARC and CAT experiences.
knghifi
1,668 posts
 
10-10-14: Bifwynne
Knghifi ... your comment applies not just to amp/preamp combos but to other system components as well, such as speaker and tube amp matches.
Not just to other system components as well but to everything in life.

If your house has no access to natural gas, would you buy a natural gas furnace? Post purchase, install propane and all the hassles in getting it to work.

Just common sense.

This is no knock on Pakwong and he has learned his lesson. Sometimes we all have to learn the hard and expensive way. Like the time I was the general contractor building my house with no prior experience. Bought the land ... cost me BIG $$ but very valuable lessons.
knghifi
1,668 posts
 
10-20-14: Zd542
"If your house has no access to natural gas, would you buy a natural gas furnace? Post purchase, install propane and all the hassles in getting it to work."

A lot of people do it that way. Not only that, you can usually make a deal with the gas company. They'll give you the gas furnace for free, along with the install, as long as you buy the gas from them.
Yes if you switch to natural gas. There's no natural gas line in my area so I have to use propane and no company is going to replace my oil furnace for free. I'll switch to propane in next MAJOR renovation.

Now I have ARC Ref250 for the winter, it should lower my oil bill. LOL!

All I get from the town is water and they are billing me $10,000+ for property tax and RISING. Can you say Detroit!
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