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
Karmicg … as far as I know, the Ref 150SE is still in the ARC lineup.  See here: audioresearch.com/product/reference-150-se/ (www prefix left off)

You raise a good question about muscle power.  The VT-200 is rated at 200 watts/per channel.  The Ref 150SE is rated at 150/per channel.  I really do not know if 50 watts is all that significant since the relationship between power and loudness is logarithmic.  In other words, 25% less power may not result in a 25% decrease in loudness.  Perhaps some of our techie members can offer an opinion.  

Here is an interesting factoid.  The VT-200 has a 674 joule energy storage power supply as compared to the Ref 150SE, which has a 1040 joule storage power supply.  See the ARCDB web site here: arcdb.ws/model/VT200.  (www prefix left off)  Just toggle to the Ref 150SE to compare.

What this means is that the VT-200's power supply can muster 674 watts/per second if a music transient is sent through the amp.  By comparison, the Ref 150SE's power supply can produce 1040 watts/per second in a pinch, … almost 50% more uuummpph.   That's a lot of back-up reserve for an amp that is rated 50 watts lighter.

I wish I could tell you with absolute certainty that the Ref 150SE will produce all the power you need, … I can't,... because I just do not know.  But I can tell you that the Ref 150SE is probably a much better sounding amp than the VT-200.  And the robust power supply might be able to carry you through.  

IMO, the Ref 150SE is a super sounding amp.  I love it.  And so far, it has not given me any headaches.  I never heard the VT-200. I surmise that the Ref 150SE sounds better because it is a current generation amp and there has been a lot of water over the dam in terms of technology, design and parts since the VT-200 was first issued.

Here's another plus:  the Ref 150SE uses KT-150 tubes.  These tubes are really something else.  IMO, much better sounding than 6550s.  A word of warning though.  KT-150 tubes are expensive and must be tightly matched.  ARC charges $275 per tube.  But here's some good news.  Upscale Audio does a really good job of super matching KT-150s for ARC amps and charges $128 per tube.  I just bought 2 quads of KT-150s from Upscale and was pleasantly surprised.  I realize that a retube could still cost some change, but the KT-150s last 3000 hours. 

And here is another most important fact:  you can easily change out the tubes and adjust bias without electrocuting yourself.  :)  That is a big improvement over the VT-200, based on the comments above.  Another word of warning.  Although I have been very lucky with bias resisters, they do blow on rare occasion.  Hopefully, you have a local tech who can switch out a blown resister, ... and even better in your home.  The amp weighs 75+ pounds.  If you go with the Ref 150SE, preorder some replacement resisters from ARC.  They are cheap.

Hopefully, my comments are helpful.  I am sure other members will weigh in too. 

Good luck and happy shopping.

BIF
I have owned a Ref 110 and Ref 150. I then placed KT-150s in my Ref 150 which brought it very close to the performance of the Ref 150SE.
The Ref 110 drove Watt Puppy7s and then Sashas. The Ref150 drove Sashas and then Alexia 2s. I test listened in my home Ref 250 monos v the Ref 150 with the Sashas and there was hardly a difference in the power department--virtually unnoticeable to me.
 I now own the Ref 160 monos with Alexia 2s. My take is that the Ref 150 has more than enough power (check out the big power supply) to drive ProAc Response 4s. Although the Ref 160 monos are the best ARC amps I have ever heard, you pay a lot for the extra clarity, power and imaging. Maybe an overall 12-13 percent difference over the Ref 150 with KT150s. IMHO, the Ref 150 with KT150s or the Ref 150SE are the best bang for the buck by far in the ARC line and indeed I cannot say enough about what a blazing bargain they are in the larger amplifier market.
Get a Ref 150 or Ref 150SE. DO NOT get a Ref 110. The difference between the Ref 110 and Ref 150 were substantial. The Ref 150 sounded more powerful and made the Ref 110 sound wispy in comparison. Hope this helps.
What gpgr4blu says makes a lot of sense.  What he did not speak about is the difference the SE upgrade made to the stock Ref 150.  I owned the Ref 150 and had ARC do the SE upgrade.

The SE upgrade is more than just a KT-150 tube drop in.  The SE upgrade also entailed numerous part change-outs.  I did the KT-150 drop-in into my stock Ref 150 and did a lot of listening.  Later, I had the SE upgrade done.  Major and very noticeable improvements across the board.  Well worth the money.

I never heard the Ref 160 so I cannot give you any comments about how the Ref 160 stacks up against the Ref 150SE.  If gpgr4blr says that the Ref 160 is about 12 to 13 percent better than the Ref 150 with KT-150 tubes, I surmise that the Ref 150SE may be closer still to the Ref 160.  

In any case, the Ref 150SE is a terrific amp.  Definitely something to consider.  

BTW, not to throw a spanner into the gears, but at some point you might want to think about upgrading your Ref 2.  Perhaps asking ARC if they still do the MK II upgrade.  

In any case, as far as the front end is concerned, you should call ARC and ask the customer service rep for some suggestions. The late model LS preamps are pretty darn good.

BIF

So I wound up going with the ARC Ref 150SE, and couldn't be happier! Plenty of power, not even remotely an issue, and already an improvement in SQ way before break-in hours.  Thank you all for your "sound" advice, I would have been lost without it!
Take care and stay safe everyone.
Mike
Congrats!!!  Good decision.  I wish you many years of listening pleasure.  

I have some "care and feeding" suggestions.  First, as you now know, the amp is heavy: 75 pounds as a stand-alone; 100 pounds when boxed up.  Consider ordering a bunch of bias resisters from ARC (2 different resisters per tube). They are cheap.  If in the rare case, a KT-150 arcs, you can avoid sending the amp back to ARC for a simple burned resister change-out.  Hopefully, you are close to a tech who can do the job, or if you are handy, you can do it yourself.  But always remember, … there are high voltage touch points all over the place under the hood. So be very careful when fiddling under the hood.

Second, if you don't have a multi-meter with probes, you need to buy one in order to check bias.  I check bias every couple of months.  The KT-150s will drift over time.  And don't get OCD about bias changes.  Bias voltage (65 mV DC on the set tube) will change as line voltage changes.  Don't go nuts about line voltage changes.  Line voltage will change by the hour, especially if home appliances draw heavy amps, e.g., air conditioners, and maybe the washer and dryer.

Hopefully, your amp came with a tiny plastic thiga-ma-giggy screw driver to adjust bias.  If not, I am sure you can buy one from ARC.  Again, … be careful about high voltage. 

Last point … tubes.  ARC charges a fortune for replacement matched KT-150s ($275 per tube).  Kevin Deal did a great job on my last re-tube.  Bias deltas between the set tube and the slave were within 3 or 4 mVs, which is good.  ARC may be a little tighter, but not significantly so.  Upscal Audio charges $127 per tube.  You need to buy matched pairs, preferably matched quads.

I have a question for you.  Which taps have you tried and settled on?  I have switched back and forth between the 4 and 8 ohm taps many times, but have settled on the 8 ohm taps.  FR may be a little tighter on the 4 ohm taps, but for some reason my amp/speaker combo just sounds better off the 8 ohm taps.  That said, FR will fluctuate +/- .8 db off the 8 ohm taps (an Ohm's Law thing), so in a sense, the amp is a bit of a tone control.  Ignore it.  No speaker is 100% flat.  And when you consider the room effects, ... that is another tone control.  John Atkinson measure the FR of the Ref 150 (not SE) here:  stereophile.com/content/audio-research-reference-150-power-amplifier-measurements (www deleted).

If you have any questions, feel free to send me a PM.  I love the Ref 150SE.  It has been a dependable workhorse for many years.

BIF

P.S. -- If and when you think about a preamp upgrade, you will be shocked by the ARC Ref 6.  Amazing!!!