Audio Research LS25 MK II ??

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The 25/2 has much better mid-bass & bass weight & definition, creating a better foundation. More focused than LS 16 (which I upgraded from). Ls 16 may be more open & airy, but lighter in "weight". Don't agree with "cold & clinical" (unless one just thinks that's the arc "sound")Didn't like the 6H30 DR variant tube, too much testosterone.My systems low end is "quite capable" so YMMV. Using with vt100/3
I currently have the LS-25 MK II which I upgraded from LS-16 MK II. I can tell you the 25II is head and shoulders over the LS-15 which I also owned. Soundstage, detail, resolution, bass everything is much better. There's no comparison between the LS-15 & 25II your talking $3000 vs $5500 which in and of itself should tell you something.
The 6H30Dr Nos is a Russian military tube which has a life expectancy of 10,000 hrs.(Conus Audio in Canada currently carries them) It took my LS-25II to another level it is much better than stock sovtek & electro harmonix tubes. Anyone that tells you tubes don't make a difference can't hear! The 6h30 tube was brought into highend audio and prominence by Victor Komenko of Balanced Audio Technology which as you know makes very good equipment. They also carry the 6h30 nos.
I'm currently mating my 25II with a D-150.2 an getting a very very good sound and have a friend who also uses the 25II with the 100.2 with excellent results.
I've been using Audio Research equipment for over 20yrs. so I know equipment and its sound.
First of all, the LS 15 is very much in the analytical zone of ARC line stages. The LS5 and LS25 in any variations would be a huge step in the right direction in the context of 3-dimensionality and harmonic richness. There was no brightness nor fatigue with the LS15, I simply found it uninvolving.

When I was looking to upgrade from the LS5 II and then later Mk III (7 years for these), I gave serious consideration to the LS25 II. The added cost to go to the LS25 made no sense. There was a little more detail hiding in the background, but it was also not as involving. I could not attribute this to the 6H30 tube as the BAT 31SE, which also uses this tube, had the LS5's dimensionality strengths but also had greatr tonal coherency than the LS5. I confirmed this at my home and at the BAT dealer. I ran with the 31SE for 2 years until I heard the Aesthetix Callisto Sig.

I had a quad of Sovtek 6H30 and the original 6H30 tubes from BAT. There was a bit of a difference and improvment with the BAT tubes, but not at all earth shattering.....not at all in the way various Telefunken, Mullard, Amperex, etc., 6922 tubes destroy the Sovtek.

The only way to answer your questions on analytical, clinical, lifeless, etc., is to try any of these in your system, directly to the LS15, and hear for yourself. There are so many line stages on the used market in the $2000-3000 range, with the Aesthetix Calypso and Lamm L1 at just a little more.

Try not to get too wrapped up in whether or not a product in this price range is 6H30 based or not. There are enough compromises in each of these models to make the type of tubes used a rather moot issue.
What perfect time for this question as I am also thinking of upgrading from a LS15 to a LS25MKII.

Has anyone heard the new LS17 that could chime in?
I am not a fan of the LS25 mkII. I find the tonal balance too dry and amusical. In my estimate, the LS25 MKI with NOS equals the MKII in bass extension and articulation, but exceeds the MKII in terms of liquidity and musicality. Perhaps, this dryness in the MKII is due to the FET input and 6H30 tubes.

Personally, I would buy a LS25MKI or the LS26 if it is affordable.
Gmorris, have you compared the 25MkII to your 25MkI in your system?
I am using LS-25 right now and I'm thinking to upgrade sometime in 2007, so now I'm thinking what my next preamp should be. I'm not excluding 25MkII from the list of potential candidates.
Yes I have done the comparison in my system. I contemplated "upgrading" to the MKII, but preferred the MKI (with NOS 6922 from UPscale Audio). I felt that the MKI with these tubes bettered the MKII. Of course it may be system and preference dependent. Upgrading to the LS26 would be the path for me. Otherwise I will keep my LS25 MKI. It remains an excellent and underrated performer.
Both LS25 models and the new LS26 seem to occupy a real sweet spot in ARC's line-up. It seems as though each model was a trickle-down from the Reference series (Ref 2mk1, then mk2, then Ref3) and represents huge value - 80-90% of the performance for 50%-60% of the price.

There are also three camps served by these ranges. The mk1 is more tube-y and warm, the LS26 is more analytical, and the mk2 is in the middle. Me, I like the mk2. I had a home demo of the ref3 and still preferred my LS25mk2.

If I upgrade my LS25mk2, it will be to a Ref2mk2 and not the LS26 or Ref3.
How does the LS26 differ from the LS25 MKII?
I also love this thread because I have the same 100.2/LS15 combo and you rarely see a good ARC thread. I've been very happy with this pairing, running 802 Matrix IIIs through a Linn Ikemi. With the cost of upgrading the preamp appearing to be in the 2-3k range, would this be better spent on a new preamp or would better speakers provide a bigger improvement for the money?
Me too!

I've been using an LS25 MkI since it came out (10 years ago?) into an ARC VT130SE and have been wondering about the MkII, the LS 26, and various used Ref options. Haven't pulled the trigger yet, but any input from this thread would certainly be welcome. Anybody compared the LS 26 to any of the Ref line stages?

Thanks in advance

Remember the general rule of thumb of the audio chain, your speakers are only going to reproduce what is sent to them from the associated equipment in the chain ie; source followed by preamp then amp an finally speakers.
"Garbage in garbage out"
Better speakers are not going to make lesser equipment sound better.
Actually, it has been my experience that once you get a decent pair of speakers, better equipment yields better results than vice versa.
Ok, I think both your points are valid so the question becomes... which $3000 upgrade would yield better results given the specific components in question, the LS15 or 802 Matrix IIIs?
I think that it all depends on the overall balance in your system at that point in time. If the preamp is the weak link in the chain then upgrading it will be a massive change, but all other things equal the speakers have the biggest impact on what you're hearing.

I think the speaker upgrade will give you more than the preamp upgrade will right now.
Thanks Dpac... I tend to agree that the speakers may be the area to focus on. I guess I'll take this to the speaker forum for some more suggestions, though I admit it will be tough to part with the 802s after all these years.
Dr version appears to be a variant, not stock version
I recently demo'd the Audio Research LS25MKII in my own room setting and equipment. With it being a tube amp, I had hoped it would reflect a little warmth but not too much. However, I was disappointed to find that it did replicate what many reviewers had stated about about the preamp...that for a tube preamp, it was very dry, brittle, and not representative of a tube preamp at all. It is truly more of a solid state preamp but one that is not neutral at all like most solid state preamps can provide. Frankly, I did not like the sonics at all. My Ayre AX7e integrated amp surpassed the sound of this preamp by a significant margin. And, its not the amp (an ARC 150.2). I heard the 150.2 amp drive many preamps very successfully as well as a pair of B&W speakers (800s, very hard to drive) very well.

But, I have found the appropriate preamp replacement for my system which supercedes the Ayre and ARC LS25MKII. Feel free to email me for further comments.

If the ARC LS25MKII works in your system, that is great! It just was too sterile and dry in mine.
Mcrheist, so what is the secret appropriate preamp replacement that you can't even mention here?

I just read my post again, and do not believe it reflects what I originally intended to convey. I apologize for my lack of proper communication in the prior post. My speakers are extremely revealing (Wilson Audio Sophia Series II), and required more power and warmth than my current integrated could provide. So I have been on the hunt for separates to include a tubed preamp and SS amp. I had the opportunity to demo an Audio Research LS25MKII with an Audio Research 150.2 amp in my environment for several weeks. The LS25MKII was not tonally warm enough for my system but I must say that I was impressed with its features and build quality, as well as the huge soundstage that it presented in my dedicated room. I really enjoy the Wilsons, they are not going anywhere, so my system required a preamp with different sonic attibutes. If my aural memory serves me correctly, I believe the original LS25 (non-MKII) ~ which seemed to be tonally warmer than the LS25MKII ~ might have been a reasonable solution. Despite the outcome regarding the preamp, the demo was well worth the time invested. I plan on purchasing the demo ARC 150.2 amp (another fine piece of Audio Research gear!) and a new tubed ARC preamp which mates very well with the Sophias (but unfortunately cost more dinero).

Regarding your question about the gain settings: While demoing the LS25MKII, I called Leonard at Audio Research and asked him the very same question. He said to keep it on the highest gain setting possible, and that is what I did. The gain settings made a fairly significant difference in performance, and after considerable hours of listening, I will have to say that I agree with Leonard's suggestion. By the way, Leonard was extremely helpful in his guidance on how to maximize the MKII's performance, so do not hesitate to call him with any questions. I was very impressed with his knowledge of the product lines, as well as his responsiveness. He actually is the one who steered me in the proper direction regarding which ARC preamp to purchase.

With proper system matching, I am sure the LS25MKII is a top notch performer. You purchased an exceptional piece of gear and hopefully it will integrate well with your system. Best of luck. Enjoy!

I bet your 100.2 will be a great match with the 25/2. I'm no longer in the preamp search hunt...I found my perfect preamp. Again, a late model Audio Research which is a perfect match for my system with the 150.2. So, finally, I am out of the game for awhile. At least when it comes to preamps and amps. :-)

I also read what stated about gain and if you are referring to the gain which is an external adjustment on the 25/2, you will just need to see what works best in your system. In my particular system which already features a few ARC components (one tube, one SS), the higher the gain, the better. Particularly for the LP phono preamp.

Best of luck.

Glad you found your preamp. As far as what Leonard recommended I was told the opposite. Try and use the sweet spot of the gain control which is supposedly between 10 and 2. I tried using higher gain settings but just didn't give me enough usable range.It ended up being either a tad too loud or a tad bit too soft? It sounds like in your system the 25MKII was not tubey/soft enough for you? I can understand completly as for using the higher gain settings to get enough output out of your phono stage. That was one of the joys of using the older ARC preamps with phono stages;) I also have Wilsons and depending on cables used they are very revealing and if the recording was bright to begin with you are going to know it right away.Having owned three other ARC preamps in the past two with tubes (SP9 and SP14 one solid state (SP7) the 25MKII is not like the old euphonic warm up the presentation preamps of past ARC build. Now if I can just save enough for that REF 3 I want!
Statman, great looking system!!! I bet it sounds awesome.

I am always impressed when I see speakers like Wilson Audio Sophia used for the rear surround channels.

If I wanted Ref3 and had Sophias parked in the back of the room(even if they are used for surround channels I still consider them just being parked there), they'd be gone along with the LS-25....and that is a Ref3 right there....but it ain't mine system, so....I'll shut the hell up.

Are we discussing two different things? On the LS25MKII, the second external knob from the left, labeled as "Gain" includes the choices of "Low" Medium" or "High". Leonard specifically recommended "High" and this was less than three weeks ago. Plenty of output was achieveable with the "Medium" setting but "High" just took it to another level. (My phono preamp is an ARC PH5). Best cables so far for my system (that are not out of this stratosphere in price): Cardas Golden Cross.

The REF 3 is what I ultimately will own, but I found the next best thing (LS26), I will have to say it offers 90% of the performance and is a much different animal than the LS25MKII.

The bottom line: Enjoy your system!
Yes we are. I played with medium and low and the low setting for me gave me the best useable range with the gain/volume control in the preamp.I confirmed it with a radio shack meter. I think the difference is I'm running all balanced so the lowest setting was more appropriate. Each system is going to be different. I agree the LS26 is awfully good and more resolute and dynamic compared to the 25MK2.
Well, I ended up skipping the LS25MKII and found a used REF 2 MKII

Any recomendations on different tubes to try? I listen mainly to rock and heavier stuff so......
ON 6H30s:
To me, the advantage of the NOS DR 6H30 is not really in the bass. The bass is less tight but fuller and richer with that tube (good and bad). Most of what I like about that tube occurs in the midrange and highs. The sound is less dry, sterile, and analytical than the standard Sovtek 6H30 tube.

Having the best useable range with the volume control / gain setting combination occurs when you can listen at comfortable levels between 10 and 2 o'clock. I have always slightly preferred the sound of the high gain setting to the medium or the low, however.
doesn't the gain setting used depend more on the input impedance and sensitivity of the amplifier the preamp is driving?

Anyway, what I've found to be the case is this -
If the amp is sensitive, then low and medium gain is all that is needed. If the amp is less sensitive, the high gain will produce better results.
I use LS-25MkI with Pass Labs X250.5 on low gain if I want a bit softer sound, more tubey so to speak. And medium gain when I want some more dynamics and punch. High gain in my system does not produce desired results. It only limits volume range. I am running it all balanced and my amp is 22kohms input impedance, so I think that explains the gain settings I prefer. I had my preamp drive a Blue Circle BC202 amplifier that has 200k impedance. We had to use high gain for best results. Low and medium gain were pretty much not driving the amp properly.
I really like the adjustable gain feature. That is the reason I am reluctant to upgrade to some other preamp. Besides, I think the LS-25 even with EH tubes sounds great. If you pop the right set of NOS tubes in, it sounds even better.
I would think the MkII will be more resolving than original with better dynamics and bass definition though.

ALso, No_money, if you could, breifly comment on the differences between Ref2MkII vs LS-15. Appreciate it.
Dpac996, I just bought a pair of 6H30-DR from The Tube Store a couple of weeks ago. I also agree with what Dave had to say about these tubes. It also sounds to me that the noise floor is a bit lower with these tubes, meaning I can hear deeper into the music.

Dave have you tried these tubes in a VT 100 MKIII?


Name it and it is better with the REF2. The things that jumped out imediatly are the solid image that is presented and the dynamics. I have not heard an LS25 in my system so not sure how it compares there? I ran into a deal on a used one so I couldn't pass it up :)
In my demo of the LSMKII, it was in a balanced system (preamp to amp with Cardas Golden Cross XLR; CD player to preamp with Cardas Golden Cross XLR) with the exception of the phono preamp (ARC PH5) to preamp. Having said that, "high" gain made the most sense in my system. And, Statman, our systems are VERY similar except mine is 2-channel versus HT. Equipment owned includes: Wilson Audio Sophia Series II loudspeakers; Audio Research 150.2 amp; Ayre CX7e CD Player; late model Linn LP 12/Ittok LVII/Lyra Argo i/Lingo; Audio Research PH5 phono preamp.

After a review of your equipment , it makes more sense to me now why the LS25MKII is considered a "worthwhile addition' in your system. Enjoy it! Best of luck! Be sure and hold onto that receipt!
I have a pair of Classe "CAM-200" mono blocks, ARC "CD-3" CD player, Classe "CP-47.5" pre-amp and Verity "Fidelio" speakers. I am looking at replacing my pre-amp with either:
ARC's "LS25MKII or "Ref2 MKII, or BAT's VK-3iXSE or VK-31SE.
I'm using Harmonic Tech's "Magic One" interconnects.
Any suggestions?
Thanks. Sally
What is your budget? I would not purchase Ref2 mkII as you can get LS-26 for $500-700 cheaper and come out much better.
The LS-26 is better than the Ref2.
Also, you can get a LS-25 mkII for about $2000 less than Ref2. Keep in mind that the REf2 is better than the 25mkII but $2000 better? I would get a LS-26.
Should I wait for the LS-26 MKII upgrade to come out?
I would think there might be more LS26's available.
Do you like the LS26 that much better than the LS25MKII?
I'm thinking an ARC pre would work well with my Classe CAM-200 mono blocks. Any thoughts?
There may or may not be a LS-26mkII. So, you could wait and see but that might be another year or year and half!
It appears you are ready right now, so why wait?
The LS-26 is better than the 25mkII period. Do I like it that much better? Let me say this,the 25mkII is a hell of a preamp make no mistake about it but if you have the money, the LS-26 is the way to go.
What is your budget? I would not purchase Ref2 mkII as you can get LS-26 for $500-700 cheaper and come out much better.
The LS-26 is better than the Ref2.

isn't the ls26 around 7k?

Used RefII is only around 4.5k +/- a few hundred.
LS26 MSRP $6000, used at $4000 +/- few hundreds. LS25mkII used at $2800 +/- $200. Can someone tell the sonic difference between the two?