Tube vs Solid State


Folks,

For past few months, I have been trying to achieve best possible sound in my rig. The focus now is clearly on a improving 2 channel sound in what started as a home theater room.  

In past couple of years, I have added N10, Modwright DAC and very recently a LS36.5 linestage . The amps are Modwright KWA150SE. I am running pair of KWA150SE's in bridge mode (450Wx1) for the mighty B&W 800D2's.  While I like the sound as is, still feel something is missing. 

I have been toying with the idea of bi-amping.  One thought is to add mono tube amps to run mid's and high's and let the KWA150SE's handle the LF's. I am pursuing that seductive, slightly warm mid-range and top end that usually comes from tube amplification.  

I don't think there is any tube amp out there by itself capable of powering up bass hungry 800's. I prefer not to use a subwoofer in 2 channel setup. I listen to mostly jazz and classical music and quite sure that 800's are capable of producing adequate bass with proper amplification. 

Any feedback would be appreciated. 

Cheers! 
128x128lalitk

Showing 6 responses by georgehifi

Don’t know about you guys, my room is 15’D x 30’W and 60db’s is plenty loud.
In that size room that’s a bit quiet for me, especially with the 800D’s, they are a speaker that’s likes to be driven to get the bass going, at those low levels I’d want the old fashion loudness switch on. And this may explain why you may like bridged mode because the damping factor is less and the bass may be warm'ish(sort of a loudness switch)

Cheers George
why he would have found the vertical biamp configuration to result in a less weighty deep bass compared to running the amps in bridged mode.
Bridged = less damping factor = less control = thicker bass (weighty?)

Cheers George
LS36.5’s output impedance at low frequencies is correct the 10K input impedance of the Schiit is likely to be a problem.
Maybe the Schiit Freya then it has xlr and se in’s and out’s

"LS63.5 Output Impedance: 110ohm"
At 110ohms, even if it were cap coupled, surely it’s still big enough, not to roll of the bass, only 2uf would do to be -3db at 7hz into the Schiit Sys’s 10kohm.


Cheers George
The only issue with padding down the gain on SS is a trip to manufacturer for gain adjustment.
Use a $49 Schiit passive preamp on the amp/s with the most gain, so you can "balanced them".

Cheers George
Modwright KWA150SE
The 800D/2/3 are a bit of a vicious load not just in the bass which can get down to an "EPDR" ( equivalent peak dissipation resistance) of around 1ohm, but also in the 8khz which can get to an EPDR of around 3ohms.
http://www.stereophile.com/images/511B800fig1.jpg

Your KWA150SE is a very good amp to drive nasty loads with as it is bi-polar output, and having 6 pairs of them per channel, so it should do great current drive into those loads, better than tubes or mosfets 
Have you tried to use it in high bias class-A mode?, (switch on the back) as this should sweeten things up and not sacrifice any solid state detail and dynamics.

Cheers George


bridge/mono mode
In every case I ever seen/heard/measured bridging a stereo amp yes gives more wattage, but your damping factor is halved and the bass is never as controlled.

Cheers George