Audio Research GS150 vs REF150 SE

Hi all. 
Has anyone compared those 2 units. Are they sonically identical. There are 10 GS for sale here on agon.
I am considering replacing my Classic 120 monos (modded by GNSC circa 2005) with either one.
My speakers are Verity Audio Parsifal Encore. An ARC dealer told me that I would be going sideways as the 120’s have more current “output” than the GS and REF which my Parsifal need. 

How do you determine the current output of a tube amp as manufacturers (tube or SS) do not spec those in their data sheet. Same dealer said to better my 120’s I should consider a stereo SS amp in the 200w/ch range or go with ARC REF250 SE. I can not sport the funds for the 250’s and would like to stay with tubes (fewer than the 120’s and 250’s) as I have a REF3 LE and REF2 phono (also modded by GNSC circa 2010).
Food for thought!!!

Let me just say I lusted after the Classic 120s all through the 1990's and beyond. I bought a Classic 60 in late1988 I think it was. Moved to the V70 a few years later for the balanced inputs. I always wanted the Classic 120's but could not afford them at the time. Especially the later CL version with the balanced inputs.I still regret selling my V70 even though I now have a Ref 110.

 We compared them not long after the GS150 came out. The GS150 is better than the Ref 150 but not the Ref 150se. The Ref 5se is better than the GSpre.  I would go with the Ref 150se if it were me.

Hi Lostbear.
I did have a CL60 for a few months before trading it in for the CL120’s in 1990. The inputs were balanced as part of the mods GNSC performed in 2005. Since 1990 I have several different preamps, phono amps, DACs, you name it, but held on to the CL120’s. Those are very special sounding amps, particularly with the Gnsc mods.
I would likely have to audition a REF150 SE in my system/room so that I can make a sound (no pun intended) decision.
So buying used,without a possibility to audition before a potential purchase is not possible.
I have listened to the Ref 150SE extensively and owned the GS150 before moving up to the Ref 250SE’s. The Ref 150SE is a better sounding amplifier and was magical with the Wilson Alexia II’s in a recent audition of the Wilson speakers. When my dealer replaced the Ref 150SE with the GS150 amp in the same listening session the magic went away. We were both surprised with the result especially since the GS150 is more expensive than the Ref 150SE. Maybe this is why the GS150 is being discontinued.

"How do you determine the current output of a tube amp as manufacturers (tube or SS) do not spec those in their data sheet"

The current delivered by an amplifier is a function of the load that the amplifier "sees" and is not a constant value. Some brands include peak to peak amp, etc., in their literature but its purely a marketing gimmick, in my opinion. The rule of thumb for an amplifier with a good current delivery, which is basically a function of a good power supply, is doubling the watts as the load is halved, 200wpc @ 8 ohms, 400 wpc @ 4 ohms, and down the line.

 I always like to hear a piece in my system before I decide to buy it. But if you buy a Ref 150se used at a good price. You can sell it and not take much of a loss if you don't like it.

 ARC has had some amazing pieces and some that were just so so. The Classic series and later V series were ground breaking. My Classic 60 was just so much better than my D70 it was amazing. But after the V series there were no real stand outs until The Ref 110. With the possible exception of the VT130. I had a VT100 mk3 for a number of years. Originally I was going to sell my V70 but found I really just preferred the V70. The VT100 did a lot of things better but it lacked presence. The VT100 lacked that rightness. It was not until the Ref 110 did I feel I could finally sell my V70. The Ref 110 has the best attributes of both. I think the Ref 150se does also. But what matters is how it sounds to you in your system.

  If you buy a new amp I still wouldn't sell the Classic 120s if it were me. I wish I would have kept my V70.

Good point about selling my Classic 120’s prior to auditioning a 150SE in my room with my speakers as I wouldn’t want to put myself in your situation with your V70. 

A friend of mine had purchased a V70 used and he did not like the sound in his room with his speakers so it went in the closet for 15 years until he decided to part with it. He listed it on Canuck Audiomart and it sold within a couple of hours of being listed. 

You seldom see a Classic 30, 60, or 120’s for sale on agon. I haven’t seen a pair of 120’s listed here in recent years anyway. The V series is actually the Classic series with balanced input and was not in production for very long before being discontinued. 

Speaking with Chris Osanna at ARC a few years ago about using KT120 in the 120’s (which he did not recommend) he was telling me that they rarely see any of the Classic series amps coming through their repair shop other than for tubes and filter caps replacement. 
He said that those were probably the most reliable pieces (built like tanks) in their amp line. I can certainly vouch for that with the experience I have had with mine.

I had the REF 150SE amps and recently have moved into the GS150. I have never regretted selling the 150SE amps.
Forget about anyone referring to 'magic.'  That is total nonsense. The GS150 amp really delivers the goods without any need for 'magic.'
The GS150 is a far more advanced amp that previous generations like the 150SE.  It is a balanced configuration and required a balance preamp.The GS150's 155 watts provides more than adequate power with generous headroom from its four KT150 output tubes.  provides tonal richness, full bass response, and an uncanny ability to create a sense of 3 dimensional space. Its sound is liquid, sweetly musical and so very engaging. The texture of the instruments was impressively tactile and so very realistic. There is no harshness or hard analytical edginess, whatsoever.  This GS150 provides true high end audio experience.
Also, he cosmetics of the GS are awesome. The giant three illuminated meters are gorgeous and very functional. The new ARC style is a winner.