Bi-Amping Von Schweikert VR4jr speakers, Kismet Extreme and ?

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Chrisandalex1

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Klaus,

I have been reading a lot about Bi-Amping the VR4jr's. 

I am curious what your thoughts would be for a Class A Tube Amp to match the Kismet Extreme Monoblocks you are building me.  Based on what I have read, it seems that a lot of guys have had extraordinary results putting a great Solid State Amp to run the Base and a smaller tube amp to run the Mids and Treble.

I was looking at the Audio Research 75

Chris

DaveC113

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Good question Chris! Have you asked Albert too? It would be interesting to see what Klaus and Albert have to say about it... not that you NEED more power though.  :green:


Chrisandalex1

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It is not about power now Dave. 

Albert has praised the Solid State Amplification for the Bass and Class A Tube Amplification for the Mids/Tweeters, and I am just playing with the idea before everything is finalized.

Reality is, that my wife will be ok with me doing it now, but once everything is in and working it is much more difficult for me to get away with changing it. 

Albert wrote the following:

"A decent, high powered solid state amplifier will give you explosive and tight bass power, while a smaller tube amp will give you the "air" and image float you are seeking from your sound system"

I am confident that what we have chosen will be awesome, but now I am curious how much better a great Tube Amp would make system.

I am also thinking I might upgrade the Center Chanel to the Von Schweikert Visiun.  :)

JackD

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Are you going to have the ability to equalize the signal to the two different amplifiers as it is unlikely they will have the exact same input sensitivity.

DaveC113

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I was kidding about the power  :)  I agree a tube amp could provide a different presentation, but the Odyssey amps are... I hate to say the old cliche but, tube-like. They are a touch on the warm side and do the dimensionality thing really well in my system. As good as the Odysseys are there is a chance that bi-amping with tube amps would be more different than better, and also a chance you may prefer the Odysseys running full range. If there is a way you can demo the amp or be able to return it if you're not satisfied that would be good. Tube amps are a little more maintenance vs SS, and you'll get into tube rolling I'm sure  :)  And they do put off more heat, which can be fairly significant depending on the amp. I enjoy tube amps and it's fun to roll the dice on ebay tubes sometimes... but some may find them to be annoying. 

Another possibility with tube amps, and what my holy grail of tube amps would be, is a high power SET amp. I heard the Arte Forma 805s at RMAF, the system is the pic in the link at the bottom of the page:

http://www.arteformaaudio.com.tw/due-volte.html

Apparently they also tried them on some huge $200k+ Scaena line arrays next door with better results than the very expensive amps with a ton of kt88s in push pull that were in the room.

Others to look at might be the Lampi GM70 amp:

http://www.lampizator.eu/newdac/lampizator/AMPLIFIER_-_GM70.html

Cary has an 845/211 amp:

http://www.caryaudio.com/products/cad-805ae/

Line Magnetic 845:

http://www.stevehuffphoto.com/line-magnetic-219ia-integrated-tube-amp-review-300b-and-845-tube-magic/

Coincident 845:

http://www.enjoythemusic.com/superioraudio/equipment/0913/coincident_turbo_845se.htm

Chrisandalex1

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What to do Dave?

Maybe I will leave it alone and tell Albert to upgrade the Center Chanel. 

I didn't really think about the heat thing, and in the space I have, this could present a problem.


Chrisandalex1

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Just an update.  I decided to stay away from Bi-Amping.

However,  I did go ahead and move from modifying the LCR-15 to buying a Visiun Center Channel speaker.


DaveC113

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You can check out the power draw of the amps, they will be equivalent to a heater of the same wattage and where you're living the AC will have to deal with the additional load.

As JackD mentioned you'd need an amp with a volume control to get the right balance...

I do think it's worth trying but I'm not sure how far I'd go to be able to try a tube amp for the highs... if it were easy to demo an amp without buying it that would be cool, and you could always look on the used market and resell it for little if any loss in many cases. There's no substitute for trying something out in your own system, it's just not always easy and convenient to do so. This is one case where the term YMMV applies and it's really hard to say if you'll like biamping better.

edit: simul-post!

kernelbob

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I apologize if I'm stating the obvious, but the first thing one should do when setting up a bi-amping configuration is to put one of the bass amps on, say, the left speaker and one of the M/T amps on the right speaker.  Drive each speaker full range and adjust the left/right level to get a reasonably close balance.  Check if the relative L/R polarity is in phase or out of phase-- a strong center image or a diffuse extremely far left, far right sound.

If you get a solid center image, then you're good to go for bi-amping.  Otherwise, you'll need to connect the bass amp and M/T amp in opposite polarity when you bi-amp, since the test showed one of the amps inverts polarity relative to the other.

If you don't test the relative polarity of the amps and connect them so the bass amp is out of phase with the M/T amp, you may not get a horribly out of phase sounding result, but the two amps will null the frequencies where they overlap, causing a terrible mid-bass hole in the frequency response.

Again, I'm sure everyone checks this before bi-amping, so sorry for stating the obvious.

Robert