Rogue Audio Atlas Magnum II

[jpwden]

ML community! Looking to drive a pair of Electromotion ESL-X speakers. I found a deal on a USED Rogue Audio Atlas Magnum II.

100 watt/channel tube amp, pristine condition, and close enough to go check it out in person. Thoughs? Is this a good amp? Will it drive the ESL-X effectively? Pros/cons?

Would like to move quick on this, so any info/advice appreciated...TIA!

 

[Lightloopy]

No personal experience with that model but highly regarded company based in Pennsylvania. I auditioned M180's monos and found them highly detailed and fine sounding. They'll have no problem driving your speakers.
Defer to other members who may have tried it out in their system.
Definitely a bonus if you can check out in person.

 

[twich54]

Rogue fan here as well. While I as well can't speak to that unit, I had a pair of M-180's driving my Spires years ago and I was completely satisfied

 

[jpwden]

Sounds like the M-180 is a serious amp. With a pair of M-180s, youre looking at 180W/ch, which is significantly higher than this amp Im looking at. However, looks like the Spire asks for quite a bit more power: 20-500W for the Spire, versus 400 for the ESL-X, and about 50% more surface area on the panel.

Seems reasonable. Im set up to go look at this thing in the next day or 2, so will keep checking here before then for thoughts. Thanks!

 

[Lightloopy]

Sorry if confusing- I meant the Rogue 100 watts should be fine. Wouldn't get hung up on the watt range specs too much. So many other variables, how loud you listen, the size of room, etc. I have a friend using my old SL3 with 75 watt Mac amplifier and is very happy.

 

[twich54]

I agree with loopy, you should be fine

 

[Stefan_DR3]

Rogue makes great amps and preamps, but again recommended for 2-channel listening only.

It uses (4) KT120 output tubes which is plenty of power but will generate lots of heat. You cannot compare tube or real Bryston power to a receiver power fake rating. These are power tubes, not small signal tubes like in a pre-amp. Down the road it will cost you about $300 a set to re-tube with mid-priced Russian Tung Sol. That's just for the output stage, there are also 4 input stage tubes that will cost as much money if you want the best sound (i.e. NOS tubes) and they will not last forever either. Most of the tubes you buy will need to be matched for gain which requires proper testing and drives up cost. Most people selling tubes on eBay are either liars or fools, and do not have a clue about proper testing or sell fakes.

HT puts more hours on the tubes so it is wise to have a solid state backup. Channel level matching becomes even more critical. Tubes are not solid state and can drift or degrade over time without you knowing until they fizzle out or get noisy. Look at Mcintosh they have a special circuit that lights up red when the tubes are failing. If the deal is right by all means jump, just be aware of the extra fussing around.

 

[jpwden]

The individual selling the Rogue ultimately wasnt budging on price at all. I ended up putting in an offer on a Lexicon 312 and offer was accepted, so for now were sticking with SS. It was less than half the price of the Rogue.

So, looks like tubes are being deferred for now. Thanks for the answers!

 

[Lightloopy]

Congrats! Enjoy and let us know how it goes.

 

[jpwden]

Amp showed up yesterday, have a few hours of listening overall. Here are my thoughts thus far:

The biggest problem Ive had so far has nothing to do with the Lexicon amp, but the dizzying number of configuration options available in my Denon 3700. It may not be as capable as the Lexicon 312 with power output, but Im ultra impressed by how far receivers have come. It took me a good hour to figure out how to get my 3700 to continue sending the pre-out signal to the sub while still keeping everything else engaged. Problem solved finally.

Additionally, I was surprised that Im still cranking the volume up a good bit to get very high volumes out of the speakers. But the sound production seems to "feel" soft while ultimately being really quite loud. I think what Im hearing is that the 3700 could produce high volumes, but it seemed to cause more listening fatigue which Im guessing is an appreciable bit more distortion than what Im now getting with the Lexicon. The Lexicon definitely feels smoother and more effortless. The detail feels about the same, but its definitely easier to listen to.

All in all, Im quite happy so far with the Lexicon 312, especially for the price. I was able to pick it up for $700 used and from what Ive seen and heard thus far, thats an incredible deal. I will say that I do think the ESL-Xs would be happy with more power still. I could envision having 2 of these and sending the bridged signal of each one to each front speaker. But this should keep me happy for some time while I play and learn about how the setup ultimately feels.

Thanks to everyone for the great advice and conversation!

 

[ttocs]

Hi jpwden! Welcome.

I would read up on what Lexicon says about what happens to the output impedance when bridged. If it's anything like any amp I've owned that's bridgeable, it raises the output impedance minimum. A couple of my amps were nominally 4Ω, but when bridged that went up to 8Ω as a minimum. That's the wrong direction. I'm sure you've heard the expression "there's no free lunch". Well, that extra power comes with a price.

I've seen the photos of your nice new room and it looks great! Can we all come over and help you tweak? We can have a DIY room treatment panel building party! I'm sure you already know you will need treatment, but before that I would suggest moving the speakers, toe in, toe out, change tilt, move the seating position, etc. Location and orientation have a huge effect on the sound quality, and it's free. Having a few absorption panels handy can help. They can be set in place and removed to hear what effect they have. Blankets, comforters, towels, and pillows can all be used a temp treatments. I've used them all with good results. For example, I took large sofa cushions and placed them on top of the woofer box of each speaker and leaned them against the rear of the stat panel to get an instant effect of pretty much cancelling the rear wave so I could hear the difference. You may be amazed at what that one tweak does!

Anyway, just some random thoughts. Be well!

 

[jpwden]

Coincidentally, I happen to see another post yesterday that was talking about the impedance changes with bridging. Definitely noted...Once again, seems like the real solution here would have been to run multiple pairs of wires through the wall to each speaker--Wont make that mistake again! Im actually still trying to figure out if theres a way to get another run of wire through somehow--That would solve a lot of problems I think.

Thanks for that. And while I imagine its unlikely anyone lives close to actually come to a building party here, I would totally get a kick out of that. I havent really considered wall treatments. Is there any kind of specific methodology for determining placement of wall treatments or providing a good starting point? Or is it just kind of trying them all throughout the room to see what acoustically works best? ALSO, do posters or framed art work ok as wall treatments? Im very interesting in trying to optimize with this as Ive never really done that and imagine there is a listening experience somewhere within that is entirely novel to me...

Thanks in advance for any info youre able to dish up!

 

[Stefan_DR3]

Additionally, I was surprised that Im still cranking the volume up a good bit to get very high volumes out of the speakers. But the sound production seems to "feel" soft while ultimately being really quite loud. I think what Im hearing is that the 3700 could produce high volumes, but it seemed to cause more listening fatigue which Im guessing is an appreciable bit more distortion than what Im now getting with the Lexicon. The Lexicon definitely feels smoother and more effortless. The detail feels about the same, but its definitely easier to listen to.

It might just have less gain so keep cranking it up. I am certain you are hearing a more "pure" sound now, gone with the harshness and fatigue. I never heard the older Bryston-Lexicons but any of the Lexicon amps I have used could only be described as muscular and lush. I would expect the Brystons to be a little more on the lean side but also very pure.

Anyway sounds like you got a smoking deal, so if it needs recapping down the road I would not hesitate to send it to the Bryston spa. You should follow them on Facebook by the way - they just posted some stunning pics of the work they did on a vintage 3B. Their workbenches are more like a medical facility than any hifi factory I've seen.

Stefan