Please help a rookie –used amps for magnepan 3.7?


This is my first post on any kind of audio forum, so I apologize in advance for my ignorance if I’m violating any convention/etiquette etc. I love music, but confessed to being overwhelmed regarding all the technical development since the days of tubes.

I am planning to buy some Magnepan 3.7 speakers. I don’t think I can afford to buy the ideal amplifier for my system right now, and would very much appreciate any advice or suggestions about what sort of used amplifier set up would be the best compromise between cost and sound quality for the near term.

I use both digital and analog sources and have Audio Research LS17SE tube pre amp and Bryston DAC and 8 year-old Rotel RB 980 BX amplifiler, which I believe is rated at 125 W. This set up has worked well with my current Vandersteen II ce speakers.

My local audio dealer told me that for the maggies I should get an amp with at least 200 W of power and suggested an Audio Research DS 225, which I could buy used for $3,900. This is a bit more than I would like to spend, however if the consensus of the group is this is the best option I could start saving towards this.

Alternatively, I was wondering if there might be a slightly less expensive amplifier suggestion somewhere closer to $2,500? (I might be able slip that one as my wife with minimal angst).

I’ve always been interested in the idea of separate mono block amplifiers. From my admittedly uninformed perspective, the logic of separate amps, potentially located closer to the speakers seem reasonable, however I have no idea if that’s accurate or even an option I should consider. Maybe I should consider getting another Rotel RB 980 like the one I have now, which I think should be fairly inexpensively – does that make sense?

I very much appreciate any and all advice and suggestions from the knowledgeable members of this community.

Thanks, Mike
mallen1010
Magnepan and Audio Research have been 'soul mates' for years. Since you already have ARC equipment, just find a less expensive used ARC amp. There are lots to choose from which meet your criteria and are in your budget. Also, remember that the actual performance difference between a 100w amp and a 200w amp is just 3db in volume.
Thanks very much, your responses are very helpful – you just increased my knowledge on this subject by 100%. I really am starting from zero.

Brauser, I like your suggestion that since I already have an ARC LS117SC preamplifier, an ARC amplifier would be a good companion.

I am really confused about all the amps ARC has made over the years. For cost reasons, I would prefer to get something used. I was advised that my preamp has "balanced" inputs and therefore I should get an amplifier that has "balanced" inputs as well. I'm not really sure what these are, and don't know if that advice is sound.

My local audio dealer suggested a ARC DS 225. I was advised that this is a class D amp, and that another type of amplifier would be a better fit for my system. Again, I don't know the difference between class D and other types of amplifiers.

Do you have any thoughts/suggestions about what models of ARC amps that meet the criteria above I should look for? Any hints about what a reasonable price to pay would also be much appreciated.

Thanks again for the help. I love music, but of all the things I really care about audio components are the thing I know the least about.

Many thanks, Mike
Mallen,

I used an ARC VS-115 with my 3.6R's that matched beautifully. I also swapped in and out periodically with a pair of Rogue Magnum 180 monoblocks that also sounded wonderful. My pre was a Blue Circle.

You couldn't go wrong with the Bryston, but I don't know whether you need that much power at all times. The Maggies project exceptionally well even with 115W.
Brauser,how does the 3 db for 100 watt's compaire to say ah, 700 wpc?, what is the increase number in db here?, then kick that to 6ohm's, mmm, which would in this case be 900 wpc, now what is the db difference between 100 wpc and 900 wpc?
You have to double the amount of power for every 3db increase in volume. 3db is a common click on the volume knob for many preamps. This means to get another 'click' worth of volume you have to go from say ...10 watts to 20 watts, 20 watts to 40 watts and so on. This also holds true at really high power levels such as moving from 500 watts to a 1,000 watts. As you can see, the law of 'diminishing returns' is at work. It may be impressive to see that 300lb,
1,000 watt amp in a system, but it is likely to not make any difference at all versus a 50 watt amp if the speakers are at all efficient. Some of the best systems I have ever heard have had amps less than 10 watts.

With regard to the choice of ARC amps, I have personally used both tube and solid state ARC amps in the past with very good results. I have never heard a bad ARC amp, although it is possible, I suppose, if the tubes are shot or the equipment piece has had some rough treatment. I buy primarily used equipment, but am picky about the visual condition of the item. Typically if it looks mint, there's a good chance that will sound good as well. One really nice thing about ARC is that they try to keep a stock of replacement parts for every product they have ever brought to market. Lots of people send their gear back to ARC for repairs or upgrades. Vintage ARC gear can sound pretty amazing in the right environments. An example is a system I had 20+ years ago using ARC M100 tube mono(s) for the treble panels of Infinty RS1B(s) and ARC D200(s) solid state for the bass towers. Lots of good memories.

Hope this helps.