[JuanR]

I have rm 40 with ampzillas 2000, kora preamp, very happy with the sound , but I am thinking about bi amping, my first thought was maybe a jolida 502, because I may need volume control to match the other amp. plus if I don't like it will be easy to sell. any comment or suggestion.

[woodsyi]

Just my impression here.  I think the Ampzilla is too good an amp to "waste" on the woofers and that Jolida is not refined enough to do justice to the ribbons. 

[JuanR]

Your are right , this is one of the reason I haven't do it. Even adding a CJ, or other high end tube amps.

[simon wagstaff]

I'd go with an AVA U70 for the ribbons....

[JuanR]

The only problem is, I need the Dyna st 70 Chassis, I went to Ava website and look like he sell only the upgrade.

[JP78]

i know every year when big b shows his rm40 they are bi-amped or tri-amped with ampzillas...including the year he won best of show i believe.  that's food for thought. folks can say what they may but from personal experience the vmps love current...i'd rather go with big current from bi-amping or tri-amping than big power of one pair of monoblocks.

[Tyson]

GO ACTIVE!  If you are going to go to the expense of getting a second amp, it makes a LOT more sense to get a modded DCX 2496 crossover and get those power-sucking passive parts out of the signal path. 

You are right on with the idea of getting tubes for the mids/highs and using SS on the bass.  The 40's are a unique speaker in that they require a LOT of current and watts to do the bass justice, but the ribbons and planars are so transparent that they really do need good tubes on them. 

[jon91661]

How much power is needed to make the mids and tweeter sing in a biamp system?  I totally agree with the fact that they love power in the bass. 

[JuanR]

I have a DEQ 2496 stock,  I used digital in and out to my modified  P3A. Any other advised about tubes?

[hmen]

How much power is needed to make the mids and tweeter sing in a biamp system?  I totally agree with the fact that they love power in the bass. 

I'm using a pair of Atma-Sphere M60's which only produce 45wpc into 4 ohms on the top half of my RM40's and I couldn't be happier with it.

[woodsyi]

I have used 8, 20, 40, 50, 100 and 200 watts on the ribbons.  8 and 20 watts were clearly lacking power.  40w was doable but sounded thin compared to the higher powered amps.  I settled on 100W for the sound that I like.  I think the ribbons need at least ~50 watts and the rest is up to your taste.  FYI, the 100W and 200W are the same amps in triode and penthode and I prefer the triode.

Now I am biding my time (need days off) to rip out the last passive crossover between the ribbons and go completely active tri-amping.  I am planning on trying my 8W 300B amp on FST and keep the others the same for a start.  Then we shall see....

[tbrooke]

I'm glad to see this thread because I've been wondering about the relative power and it appears that the midrange panels still need some power but the tweeters don't. I'm thinking of a lot of power (200 watts) for the lower 100 or so for the mid and tube or a Pass F3 for the top. Most people that have posted seem to be going the digilog route but I would be curious to hear about the full 3 way set up to see if the active crossover can do anything at the higher frequencies.

Tom

[Tyson]

I've tried 125 watt amps on the mids (VTL MB125's), 85 watts on the mids (VTL ST85), and 35 watts on the mids (VTA ST70).  All of them sounded great.  I'm also running a monster, 2 box, fully differential solid state amp on the bass, 500 watts into 4 ohms. 

Fully Passive - I find that the higher power amps are needed when you have the passive crossover in place.  The MB125's are the smallest amp I'd run the 40's full range with.

Actively Biamping - There are still a few passive crossover parts in the signal path if you actively biamp, and my findings are that a good, powerful amp is needed for the woofers, but a medium power amp if fine for the mids/highs.  The ST85 was perfect, putting out a very good sound and able to go louder that I'd ever want to hear.

Actively Triamping - With ALL of the passive crossover parts (plus L-Pads) removed from the signal path, you need 3 amps, one for the woofers, one for the mids, one for the tweeters.  I find that with all the passive parts gone, power requirements go way down.  I run the mids with a VTA ST70 which is 35 watts of EL34/KT77 power, and I run a second VTA ST70 on my tweeters.  Dynamics are insane with this setup, and clarity/transparency is a big step up from the already-great passive RM40.  At this point, tube rolling has a larger impact on the sound you hear, as the amps are more or less directly coupled to the drivers. 

[Tyson]

Oh, and I forgot to mention, the active crossover is a LOT of fun to play with, giving you a lot of control over contouring the 40s to get the best sound in your room.  I find that the panels get a little beamie above 3khz, so I cross the tweeter over at 4khz with a steep LR-24 or LR-48 phase coherent crossover.  And I also cross the woofers at 350hz, with a steep LR-24 phase coherent crossover.  Sound is pretty phenomenal.  Put in a little 3db dip at 3khz to take care of panel response peak, and you've transformed the 40's to the next level, a level that VERY few speakers I've heard even come close to.

[JuanR]

Excuse my ignorance but where I can get the st-85.

[Tyson]

Actually, I'm selling mine, so PM me if you are interested in it. 

[tbrooke]

I am just thinking about the ultimate SDE setup  - I have rm30m but it should be the same for the 30 or 40

I can see tubes on the fst but what about the panels? The high frequency will be rolled off with the crossover and it seems that they may need a little more power than the fst. I would say tube (or Pass f3) on top, about 15 watts  -  On the panels maybe 0 to 100 watts tube or solid state - lots of power 250 watts or so for the woofers.

Tom

[Hipper]

JuanR: a Behringer DEQ 2496 is a digital equaliser; it can't be used alone to give you active speakers. For that you need the Behringer DCX 2496 that Brian sets up for his SDE speakers. The DCX includes a digital equaliser.