[PhilNYC]

Have any of you paired a good tube preamp with a "digital" amp (class D or other)?  I was thinking this might give some of the benefitis of the tube sound but have lower heat output and still have the ability to drive some heavy loads. 

I've paired a Bel Canto S300 stereo amp with a Blue Circle BC3 tubed preamp with excellent results (although I still prefer the Blue Circle hybrid amps to the Bel Canto)...

[miklorsmith]

As far as vibration isolation, I find class D amps just as sensitive as front end components and the better the isolation, the better the overall sound . . . In my experience, the sensitivity to vibration is higher than that of solid state or tube amps.

   Wow, I would expect tube amps to be the most sensitive of these choices.  Very interesting.

[macrojack]

My RWA Sig 30 uses battery power which, of course, removes all concern for power conditioning and since it only weighs like 12 pounds, it can be isolated nicely on a small pillow. With efficient speakers (the only kind worth having) it will play quite loud with powerful dynamic contrast.

In case you don't know, RWA offers a 30 day money back guarantee. How can you go wrong? Get a taste of the 21st century.

[Occam]

My interest in switching amplification stems from my recent listening to an Innersound Kaya Reference speaker system. It comes with a 600wpc bass amp/crossover. Through its transmission line bass with 10" Seas woofer, crossed over at 350Hz (and my mods to the crossover electronics  ) it was stunning, the best bass I've ever heard.
http://www.innersound.net/kaya.html

But a 600wpc class AB amp, even low bias isn't cheap to buy or build, as it requires substantial cost beyond the amplifier itself, the powersupply and heatsinking. Regardless of subjective differences might have as to the midrange on up preferences, many feel that switching amp implementations can do an outstanding job in the lower reaches.

I've recently been playing with bi-amping of my own long in the tooth Alon IV speakers. As much as I'm awed by the bass performance of my Aspen LF100 amp, it is, after all, still a 100wpc amp. Alon suggests a minimum of 300wpc.

Soooo, what I really want is a behemoth subwoofer amp/active crossover, but minus the sub part. I'd want it to crossover between 250-450Hz, and a conservative 500wpc+.
Obviously, I also want a perfect controllable highpass and lowpass crossover, and the requisite parametric equalization / room correction for the lowpassed bass. But that isn't specifically germane to my desire for massive bass amp power, which a switching amp could provide at reasonable cost.

FWIW

[JoshK]

Your in my camp then.  I believe in using the "sweet" amp up top (one can argue about where that begins) and use something with real force down low.   That is why I built the UcD's knowing ultimately my desire to build tube amps.  Even with pro audio woofers (I have 95db 15" Lambdas) I think one needs an authoritative amp for the best transient performance.   Switching amps are great for that, they don't draw tons of electricity and they don't put out gobs of heat. 

[zybar]

My interest in switching amplification stems from my recent listening to an Innersound Kaya Reference speaker system. It comes with a 600wpc bass amp/crossover. Through its transmission line bass with 10" Seas woofer, crossed over at 350Hz (and my mods to the crossover electronics  ) it was stunning, the best bass I've ever heard.
http://www.innersound.net/kaya.html

But a 600wpc class AB amp, even low bias isn't cheap to buy or build, as it requires substantial cost beyond the amplifier itself, the powersupply and heatsinking. Regardless of subjective differences might have as to the midrange on up preferences, many feel that switching amp implementations can do an outstanding job in the lower reaches.

I've recently been playing with bi-amping of my own long in the tooth Alon IV speakers. As much as I'm awed by the bass performance of my Aspen LF100 amp, it is, after all, still a 100wpc amp. Alon suggests a minimum of 300wpc.

Soooo, what I really want is a behemoth subwoofer amp/active crossover, but minus the sub part. I'd want it to crossover between 250-450Hz, and a conservative 500wpc+.
Obviously, I also want a perfect controllable highpass and lowpass crossover, and the requisite parametric equalization / room correction for the lowpassed bass. But that isn't specifically germane to my desire for massive bass amp power, which a switching amp could provide at reasonable cost.

FWIW

Paul,

If you didn't want to go up so high, I would suggest the Crown K2 amp.

I know that the K2 isn't a class D amp, but it is the best bass amp I have heard!!

It is relatively small, no loud fans, and can handle anything you throw at it.

I haven't tried it above 120Hz or so, so I can't say if it is refined enough to do you want it to do.

George

[JoshK]

Well I have a K1 he could borrow if he wanted to try that.

[macrojack]

I'll second Zybar's K2 recommendation. I have one now and it is the best bass amp I've heard including Pass, Rowland, Krell, Classe, McIntosh, Goldmund and Bryston. Like George, I can't testify above 50 hz.

[miklorsmith]

Yep, the K2 is a mutha on the low bass.  It's the first (only) amp I've found that can control the 8 - 10"ers properly.  I'm only using it to 70 hz though.

[Occam]

Gents,

Thanks for the suggestions. I realize there are some tremendously powerful (pro)amps out there that provide great bass service. They might well be as good into the midrange; I just don't know.

My fantasy speakers are still 3 ways, and IMO, that requires a crossover in the 250-450Hz range. And iff'n I'm going to cross that low, it provides an opportunity to bass/room correct in that frequency range, and dedicate an amp to it. (yes, I know about room treatments, etc..., but that isn't germane to this post) I do realize that many will find their own audio bliss with lower power, but for my needs/wants, I'm a Sir-MixaLot sort of a guy. So I want power for bass, and I want to extend those woofer duties upwards to something below 500Hz, for a variety of reasons, psychoacoustic, electronic and driver related. If you'd heard a Innersound Kaya, properly set up, you'd see where I was coming from.
While the Kaya electrostats are amazing, they're not my cuppa. But that base of powerfully amped, no passive lowpass bass/lower-mid provides a great starting point. Heck, put a dipole mid and tweet on top of the base/bass bin, and you've got my Alons, but better. Or put horns on top, whatever....

While I'd never, ever, consider a class A 1kW audio amp, having a couple 1kW amps to drive those bins is very appealing, as long as I can rationalize it as a 'green' approach. One could have a big mutha powered bass base and use a low powered SET and still not consume massive power.

And as a blank slate, this approach calls for a switching amp on those bass bins.

FWIW

PS- Nomad Audio is taking a similar approach with their Ronin A, which I've not heard.
http://www.nomad-audio.com/ronin_1_0c.htm
It uses a 500wpc Bash amp (not a switching amp, but with a 'trick' switching ps) to power the woofer directly up to 250hz, while providing the customer some equalization for bass extension and a single channel of adjustable parametric equalization. I allows the customer their own choice as to mid-tweet amp.

[Vapor Audio]

If you didn't want to go up so high, I would suggest the Crown K2 amp.

I know that the K2 isn't a class D amp, but it is the best bass amp I have heard!!

It is relatively small, no loud fans, and can handle anything you throw at it.

I haven't tried it above 120Hz or so, so I can't say if it is refined enough to do you want it to do.

I tried my K2 once full-range, just for the heck of it.  It was listenable, but by no means good.  Run ful range is sounds like an Adcom 555.  The bass though like everyone says is fantastic, although I prefer the bass from a ICEpower 1000ASP module. 

I'm using my K2 to power 4 AV15's btw, and it does a heck of a job