Tube amp for Magnepan 3.5 with autoformers.


I just purchased a set of 3.5s and am using a Plinius 9200. I would like to get a tube amp but know Maggies need alot of power. I am considering Speltz autoformers. Any sugesstions? I don't know how much power I will need with the autoformers. Am I better off without the autoformers as I have no experience with them? My budget is under $2500 used. I listen to mainly accoustic, female vocals, and jazz but do listen to some rock and classical. My room is 17 x 28. Would I be better off with a tube pre and a ss amp? I know there are alot of threads on Maggies and amps but would like to hear some fresh ideas.

Thanks, Pal.
Ag insider logo xs@2xpal
You only need autoformers if your amps can't support a solid 4ohm load that Magnepans require.
I've had extensive experience with 3.5R's and you need serious tube power to make them work as well as with a high quality solid state amp. Unfortunately, high power tube amps don't come cheap. We're talking a mandate of 150+ watts.

The autoformers will help (expecially with OTL's) and cure a few problems. Fortunately, Maggies are a mostly resistive load, so they don't change sonically as much as other combinations. IMHO, this applies to speaker cables as well, I wouldn't throw a lot of money at speaker cables expecting great change, just subtle changes, so watch your wallet and audition as necessary.

To be honest, I'd consider sticking with the Plinius line with a dedicated amp and using a tube preamp to help get the sonics timbrally more correct. I was told a long time ago by a dealer that if you have Maggies, you need tubes somewhere in the system. I would have to agree based on my own experience. Another great match seemed to be big Pass amps. Bryston mono's are maybe less sexy, but seem to be a very good match as well with most maggies, especially the larger panels.

With all that said, large VTL's tube amps will sound a little sterile, but have great control. Big OTL's will ruthlessly reveal upstream problems, but strike a nice balance and sound very natural. Big ARC tube amps like VT-200's set up as monos will be all right, but may grenade with a tube arc-over so they're a bit stressful during loud passages. LOTS of tubes per amp will sound nice and look great at night, but you will need all those tubes to make the 3.5's sound better than a good SS amp.

Also, watch your midrange fuses during loud passages, when the fuse pops, it seems to shovel more power to the ribbon tweeter which is more fragile.

Good luck,
RFG
Thanks for all the input. I spent a couple of hours with my buddy finding the best speaker placement and that improved the sound. After finding the right location we put the spikes on the MYE stands and that also provided better focus. I like the sound of the 9200 but would still like some tubes in the mix, so I may stick with a SS amp and go with a tube pre. I do not listen extreamly loud so I wonder if a 100 watt Plinius amp would be enough power. The 9200 has 200 watts a channel but I don't belive it doubles into 4 ohms. It has enough power for my listening levels.
Guys, just a thought:
the 3.5s are bi-wireable, thus, bi-ampable... wouldn't 2 tube amps (of the same kind/type) work some magic?

2 tube amps of different kinds/types would need some cross-over, but 2 of the same would not as a preamp with 2 outputs would do just fine.

what do you think?

i hope this is not OT :-|

Thanks
.e.
I'm using a Mac tube amp with 1.6's and nordost cables and am very pleased. I crank it up on occasion and no issues with the sound or the amp.