Suggestions please!! --Need to replace vintage Audio Research VT 200 Tube Power Amp


I have a nearly 25 year old ARC VT200 amp, which just arc'd out on me for the 3rd time in 18 months, and I have decided I cannot sink any more money or aggravation into this amp. I purchased it used about 7 years ago, and it had just been re-tubed, and it ran problem free for me for over 5 years. Then without warning it arc'd out, resulting in a replacement of all tubes, capacitors, etc.  10 months later, the same thing happened again.  I nearly bailed on it then, but the repair shop assured me that they could "really fix it" this time, blaming the repeat issue on the need to replace all of the tube sockets and repair some thinning wiring, and they assured me it would be "like new" and should run problem free for years to come.  It's been 9 months, and it's been running fine with relatively light use (probably 300 hours since the repair) and last night the fireworks happened again. Needless to say, I've now reached the end of the road with this amp. 
So my questions are these--as much as I loved the amp (when it was working!) a comparable new ARC tube amp (which appears to be in the $15k+ range) is out of my price range. The VT 200 is currently paired with an ARC Reference 2 preamp and a tube ARC phono stage from the same era, which are working fine, and they are driving a massive pair of ProAc Response Four speakers. I listen almost exclusively to vinyl on a VPI turntable. Does anyone have a suggestion for a new power amp for under $10K (after this experience I am reluctant to go the used route)? Also, would it be OK to pair a solid state amp with these tube components, and if so, any recommendations?  Thanks!!
karmicg
To the OP.  Sterophile reviewed what appears to be your speakers, here:

stereophile.com/content/proac-response-4-loudspeaker-measurements

(I deleted the www prefix in case the link is deleted.)  

If this is your speaker and you plan on keeping the Proacs, JA noted a couple of points that should be kept in mind.  First, the Proacs are not very sensitive.  JA measured the Proacs' sensitivity to be 85.5db, which is not high.  That would suggest you will need power to get the best results from your speakers.  

Notably, I checked the ARCDB website and looked up the specs on your VT-200. Your current amp has a rated power output of 200 watts per channel and power supply energy storage of 674 joules, all of which permits the inference that you have a pretty hefty amp.  

Second, the Proacs' impedance curve is pretty rocky. JA comments that a high output impedance tube amp would add sonic coloration to the speakers' frequency response.  The ARCDB website reports that your VT-200 has a low'ish output impedance of less than 1 ohm (damping factor is 11).

Although I am a fan of ARC products, if you are trying to keep costs down, you might find that you are biased (pun intended) to look for a quality solid state amp that has a lot of rated power.  There are many fine brands on the market and I'll let other members make specific recommendations.

That said, if you are inclined to stick with a low'ish impedance tube amp with umppff, in general, and another ARC amp in particular, you may want to consider the Ref 150 SE. If too pricey, maybe a Ref 110 if you see one pop up.  I own the Ref 150SE and it drives my speakers like a champ, but then again, my speakers have a rated sensitivity of 92db.  

I have another suggestion.  I think your VT-200 is a pretty good match for your Proacs for the reasons explained above.  I appreciate your frustration with frequent repairs, but nobody knows an ARC amp like ARC.  Why not call ARC and see if they can go over your amp from top to bottom.  I am sure ARC could put your VT-200 back to original spec and augment its reliability factor, … if they still repair the VT-200.  You should also ask ARC if your amp can run with KT-120 power tubes.  That would make a big difference in SQ.  I would also ask if you can have the MK II upgrade done.

In any case, I would be hesitant to drive your Proacs with much less power than what you have now in your VT-200.  

Hope this helps.

BIF
   

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The B+ voltage on the output tubes is too high for those Russian-made KT-series tubes! This wouldn't be a problem for original USA 6550's or British KT88's. But NOS supplies of those tubes are practically nonexistent! ARC shouldn't run those Russian tubes so hard! This has been a constant problem with ARC tube amps for years!
Excessive screen-grid voltage/current is another problem area which can lead to tube death!
Get rid of that VT200. Buy a Crown XLS1502. 600wpc/4ohms!  $439! And it will still be working into the next century!