[Pez]

Just curious to know if any of you RM40 owners out there (or any other similar VMPS speaker owners) are using a SET or SEP amp with their 40s? I built my own amp specifically to run the tweeters on my RM40s. I anticipated needing approximately 3-5 watts of power to match the 60 watts of power I have using the Bella extreme 3205 modded amp.  I should mention that I have the 40s actively amped using a 400 watt amp for the woofers already allowing the Bella to take care of everything from 500 hz up. 

Well I finished my amp project a while back and to run the Simple SE in I decided to hook it up to the 40s in place of the Bella until it was broken in and I had finished building the cabling required to hook the amp up to the speakers. Low and behold the mere 5 watts SET (or 12 watts Single ended pentode) I was using on this amp was WAY MORE than I needed to drive both the midpanels and the tweeter in excess of 93 db. I hate listening to music much louder than that so I never went over 93 db.

Needless to say I was stunned at the results, while I am going to reserve judgement on the overall sound quality in comparison to the Bella until I am able to do an in depth side by side I will say this, the single ended low powered triode amp with the 40s sounds down right phenomenal. Better than I ever would have imagined a 5 watt amp could run these beasts. I think SET and the 40s is a match made in heaven. 

Have any of you had any experience with a similar setup?

[Russtafarian]

Maybe Brian can chime in on how driving only the midpanels and tweeter presents a different impedance/back EMF load (or whatever) to the amp vs. driving the whole system with woofers.

Sounds like a good use of 5 SET watts to me.  Now you got me thinking of building one for my '30s.

[BobRex]

I run a 2A3 SE amp (Wellborne Moondogs - 3.5 watts with EML meshplates) on the ribbons of my RM30s.  The woofers are run by a BPS plate amp.  The sound has some of the typical issues of SE amps, favoring the direct sound over the ambient.  You can hear the room on many recordings, but it's not as obvious as on some push-pull amps.  On the other hand, there is a purity to the mids and highs that you may never hear on pp. 

[hmen]

The ribbons seem to work really well with tubes. I normally use Atma-Sphere M60's (45 wpc @ 4 ohm) on the ribbons on my RM40's and never seem to lack power. Just for fun I tried my Wright Sound 300B's on the ribbons and they were more than adequate.   

[Pez]

I'm going out on a limb here and I'm going to say that because the RM40s are easy to drive and high efficiency, nobody EVER is using more than 10-20 watts of output from their amp (assuming biamping of course) at the highest of outputs regardless of what kind of amp they are using. Now I'm going to go even further out and say most people are probably using only 2-4 watts when running them. At 93 db I personally could barely stand the absolute volume of sound that was coming out and there was no noticeable distortion, if my SPL meter is remotely accurate then these levels are not only peak power, they represent sustainable power.

I really think people need to re-evaluate their setup with the 40s. Way too much emphasis is being put on putting a lot of juice behind them and while I agree the woofers need lots and lots of Solid State goodness (or high powered push pull etc), the mids and tweets need flea power and flea power sounds more wonderful than you could imagine.

[Russtafarian]

...the woofers need lots and lots of Solid State goodness (or high powered push pull etc), the mids and tweets need flea power

That's been my experience with RM30s.

...flea power sounds more wonderful than you could imagine.

Great, now you got me thinking about yet another audio project.