Any experience with Arc ref75 driving magnepans

I read the Stereophile review of the Ref75 and they mentioned the appearance with the meters was similar to the D79. If the Ref75 will not drive magnepans, however, that must be the only similarity between the 2 amps. I say that because I have a D79 and it drove my MG1.6's better than anything I ever had, and at high levels. At the time it was much better than the Bryston and McCormack Solid State gear I had in terms of perceived power and tonal quality. Looks like the Ref75 is a step down, however, which is to be expected because it is about 50 lb compared to the D79 which is about 100 lb.

I will preface this by saying that I listen at high volumes sometimes. That being said, I bought a pair of Maggie 3.7 six months ago as something to play around with (the everyday speaks being Focal Alto Utopias).

WOW!!!....the 3.7s have me burying the big blue meters on the McIntosh MC501 amps (500wpc into 2, 4, & 8 ohms) on a regular basis. I often times switch amps and speakers in and out of the everyday system for fun (that's what we do, right), but I have never had to turn the volume knob like I did when I put the Maggies in line.

The 3.7s are a fantastic loudspeaker for what they do, but their power hungry reputation is well deserved.

With the Stereophile test bench numbers and the Maggie's appetite for watts and your suggestion that you may want to "get on the volume" from time to time, I would recommend you look at power alternatives--maybe one of ARCs hybrids....my $.02.

Btw...I am using a class D power amp from Peachtree Audio to power the Maggies in a second system now...220/400 watts 8/4 ohms respectively and somewhat pleased with the results.

Pepe

Directly from the mouth of Nelson Pass.

"Our experience is no problems at all with the ARC or CJ products with regard to interface. The amp doesn't care about source impedance. It's actual input impedance is close to 0 ohms, and the input impedance spec comes from the resistors we put in series with that input. Adding a little more from the source doesn't create issues."

Chuck

Jimford,

I still have the Ls-27 and I think it is very good. I don't know why people would say it's not a good match with the Pass
xa30.5. I haven't heard the REf-75 but I have read it is excellent. My next move will probably be a used REf-150. I'm still waiting for the prices to drop but I have a feeling it might be a couple of years.

Taters,just wondering if you still have your ls27? I just got mine and I love it! What prompt me to start this thread was from reading threads stating that the ls27 wouldn't be a good match with the pass xa30.5 ...well to my ears it is a great match so far...That doesn't mean I won't try the ref 75. Because I think I will...What a great and rewarding hobby we have! The gift of music..

Don C-55,

I have to disagree with you about ARC tube amps. I have owned 2 of them for the past 15 years and all I have ever done is replace tubes.

I was looking at this amp as well but was put off by the specs that Stereophile reported. I was also turned off with the fact that the VSi60 blew a resistor while on the test bench when Stereophile reviewed it. Doesn't bode well for ARC in my book.

ARC "lied" about the power of the Reference 75!

Per the Stereophile testing:

Audio Research specifies the Reference 75's maximum power as 75Wpc (18.75dBW into 8 ohms) at typically 0.6% THD. Figs. 5, 6, and 7 show how the THD+noise percentage increases with power into 8, 4, and 2 ohms at 1kHz from the 4 ohm output transformer tap. We define clipping as when the THD reaches 1%; the Reference 75 doesn't quite meet its specified power at that level of distortion, delivering 61Wpc into 4 ohms (14.8dBW, fig.6), and lower powers into the other impedances: 43Wpc into 8 ohms (16.33dBW, fig.4), and 40W into 2 ohms with one channel driven (10dBW, fig.7). However, relaxing the definition of clipping to 3% THD, the Reference 75's 4 ohm tap gives 46.5Wpc into 8 ohms (16.67dBW), 70Wpc into 4 ohms (15.45dBW), and 94W into 2 ohms (13.7dBW). Slightly more power was available from the 8 ohm tap into 8 ohms (fig.8): 70Wpc at 1% THD (18.45dBW) and 78Wpc at 3% THD (18.9dBW).

This amp will not be useful except for very low volumes!

My amp now is a Pass labs xa30.5 only 30 watts but it doubles in 4 ohms.

Yes, 30 watts in class-A. "While the XA30.5 may give 30Wpc into 8 ohms in class-A (14.8dBW), the distortion at this power level is low, at 0.015%. The amplifier doesn't actually clip (defined as the THD reaching 1%) until a much higher power level: 130Wpc into 8 ohms (21.14dBW). Even higher powers were available into lower impedances before clipping: 195Wpc into 4 ohms with both channels driven (19.9dBW), and 332W into 2 ohms with one channel driven (19.2dBW)." Measurements

Wow a 30.5 drives the maggies with no problem. Does the needle jump around much? I suspect then the ref 75 would drive them as well. The only issue then is dealing with power tubes and a the maintaience of a tube amp.

I have had both ARC and Pass Labs in my system and both companies make some of the best, most reliable amps around. Granted tube amps are intrinsically, more likely to break down than SS, but I really can't agree with Don c55, that ARC have reliablity problems.

I can't comment on the Reference 75 and matching with Maggies, but the consensus seems to be that they will drive most speakers, except the most punishing, to sensible volumes. On a prolonged recent audition, I thought the Reference 75 was one of the best sounding amps I have heard and I plan to buy one, when funds allow.

Whether a move from the Pass to ARC is a step sideways or up, I think you would have to audition in your system, but at these prices I would take that as mandatory anyway.

Keep the Pass XA30.5!

More peak power at 4ohms, and better sound quality. No tube hassles like break-in, ageing, blown resistors, and trips back to ARC.

I have experience with ARC tube equipment, and they work fine a minority of the time!

I appreciate all of your input.I guess I should give you my room size.20x16x10ft ceiling.My amp now is a Pass labs xa30.5 only 30 watts but it doubles in 4 ohms..I know with Maggie's it's not all about the watts but the current of the amp.The 30.5 powers the Maggie's without any problem.The more info I can get on the re75 powering Maggie's the better...Thanks again

The Ref 75 is an excellent amplifier but not nearly enough power to drive those speakers correctly. Good Luck

I know someone who drives Apogee Duettas with the new Ref 75...he says it is an absolutely glorious amp in so many ways and handles them quite well. I would say if it drives them, it will drive your Maggies [as long as the room isn't especially large]. Good luck with it.