I'd appreciate if any of the VT100MkII owners can share their thoughts about this amp.

I am considering this amplifier.
It will be run via balanced cables with the rest of my ARC components - LS-25MkI preamp and CD3MkII cd player.

Cabling is Acoustic Zen Silver RefII from CD3MkII to LS-25 and Matrix RefII from LS-25 to amp. Speaker cables are Acoustic Zen Satori Shotgun.

Questions I have about the VT100MkII amp:
1) What is its sonic signature? Is it relaxed, laid back, forward?

2) How hot does this amplifier get?

3) How audible is the fan noise from about 7-8 feet away at low volume listening?

4) Will it manage to drive my B&W N803 speakers?

5)Any issues such as reliability aside from re-tubing?

I listen mostly to rock, blues, jazz and some classical. I like natural, dynamic presentation, but not harsh, analytical or forward sounding. Imaging and soundstaging is important. Good bass is a MUST.

I have listened to this amplifier before and the only think I remember is that I really liked it but it was long time ago and it was driving speakers that are easier on amplifiers than my N803s are.

Thanks very much for your thoughts!
I owned a VT100MkII for a few years, & used it with my b&w M802 SIII speakers. The VT100MkII is a great amp, but I found it didn't have quite enough power to make the 802's sound their best. Weak or muddled bass was one problem. I finally sold it, & bought a C-J MF2500A SS amp that really brought the 802's to life.

I think with the more hard-to-drive b&w's, tubed amps are not the way to go. Unless you could afford something like a VT200 maybe (?), or the larger VTL monos, but, there are a lot of nice SS amps available for a lot less $$.

Oh, I used the VT100MkII with Merlin speakers also; that was a nice combination.
The "sonic signature" can be perceived quite differently for each person, I found the ARC amps to be natural.

The amp can radiate a lot of heat, they don't feel hot to the touch because of the fans, but, the can/will warm up a small to midsize room.

The fan noise is not an issue, you won't hear the fans after a couple of feet distance.

Not familiar with your speakers so to tell you sure, buy the amp and than they not work would be irresponsible.

ARC equipment is one of the reliable and durable amp/pre-amps one can buy. They will service every piece they have ever made and most are still in service. Retubing on the VT100MKII should be done by a certified ARC tech. This amp is not user friendly. Enclosed is an attachment that explains how to do it. You will have to decide whether you want to tackle this job.

I have used ARC equipment for years and I have become quite found of their products...........Bob
Thanks Steve. I have a nice SS amp. I just want to try a tube amp and see how I like it vs SS.
I would assume that the Matrix 802 are a more difficult load for an amp than my N803. But even the N803 are not easy to drive.

Thanks Bob for that link. Going by what's involved, I think I'd opt for a tech to do this. I have an authorized ARC technician nearby, so this shouldn't be a problem, I mean as far as shipping the amp, I don't have to do it.

I guess this may be trial and error kind of deal. But please keep the suggestions coming. If anyone has experience with this amp and my speakers, or anything esle in the Nautilus line with this amp, it would be great to know what the combo sounded like.
I owned this amp for like a year, so I'll respond where I can.

1) What is its sonic signature? Is it relaxed, laid back, forward?

I felt that this amplifier is slightly forward. In my system it did not sound relaxed or laid back, but it was also not an offensive 'forward'. I felt that this amplifier draws vocals out a little and makes them easier to hear. It had a dry-ish sounding signature in my system, and I eventually sold it because of that. I felt the (dry) sound was a sonic signature that I coudn't live long term with, even though it was quite appealing for about a month.

2) How hot does this amplifier get?

It gets fairly hot right beside it, but it won't warm your room.

3) How audible is the fan noise from about 7-8 feet away at low volume listening?

I found the fan to be audible from a listening distance of 9 feet. It never was inaudible during silence. However, once the music plays you do not hear it.

5)Any issues such as reliability aside from re-tubing?

I never had a problem, but when I sold the amplifier the next owner said a cap or something went bad and took a whole circuit board. I would guess that isn't typical.
I truly hate when someone asks about a certain piece of equipment, in your case an Audio Research VT100 mkII, and a response comes back, well have you considered a BAT, or a Cary, or conrad johnson, that being said, have you considered the ARC VS110. It obviously has the Audio Research sound, a little more power, much more user friendly and no fan noise. Unfortunately they are more expensive but I thought I would throw it out there. Now I will go and beat myself up for even suggesting an alternative.............Bob
All your other issues aside, how can you consider a tube amp if heat is a concern? You can`t change the laws of physics.
Audphile1, I don't know how much more difficult the M802's are to drive than the N803's. I've owned several sets of b&w's tho. With my M802's, I was usually thinking, TWO VT100MKII's might be the ticket.

I did re-tube my VT100 myself once, & almost electrocuted myself--I got zapped, but good (you have to bias it with the amp turned on). I think I got a quote of $500 + shipping each way to have ARC do it.

If you want a tubed power amp, & don't mind schlepping it/paying for retubing when the time comes, would a larger amp, or monos, be a possibility? Just with the larger, floor-standing b&w's, I'm thinking, 100 wpc? I dunno.

Just my 2 cents, good luck, steve
I loved my ARC VT100Mk2. Sound was natural and warm. Would refer you to my comments in other threads as to my experience tube rolling it. Then, I liked the Svetlana power tubes; now, I would recommend using the Russian Tung-Sol 6550s. Still have the 6DJ8s if you are interested. Had good results matching the amp with both the Mirage M3s and the Talon Khorus X M2. It may be a little power shy for the N803s. May I suggest the Von Schweikert VR-4Jrs? With the proper modifications (custom spikes, 50 lbs of weight and bi-wired) they rival much more expensive speakers like the Talons. David
Bob, don't beat yourself up. Thanks for a suggestion, but if I try a tube amp it has to be a balanced design. I'm not a big fan of BAT equipment. But thanks again.

Wberdan, thanks for your comments. BTW, did you run the VT100MkII balanced or single-ended? And what was the assosiated equipment. thanks.

Mrwigglewm, thanks. Unfortunately, upgrading or changing speakers is not the plan, at least at this point in time. Sometime in the future, I may consider the VR4JRs. But thanks!
Steve, well that's my biggest concern. The power of VT100MkII may not be enough for the B&Ws. Although I had a 100w/ch SS amp(McCormack DNA-0.5 Deluxe) it sounded quiet good, but the bass was always a bit boxy sounding. The woofers on the Nautilus are pretty tough. When I went from DNA-0.5 to DNA-125 I noticed a very slight improvement in bass and it became clear to me that more power is needed. So I stepped up to DNA-225. I do really like this amp. It is a very good sounding piece, but I figured, I would like to try tubes. The rest of my gear is all ARC, so the natural match in tube amps(out of the ones I can afford) is the VT100MkII. I wish I could try it first, but the probability of that is close to zero. I'd love to get VTM200 but they are very big and at this point out of my price range.

Porziob, heat is a small concern only, but as long as the amp does what I want/expect it to do, I could care less.

Hot, but it vents nicely.

Fan wasn't noisy to me, but I had it on a separate circuit so I could use the PP (see below) and likely had it running a little slower than stock.

Retubing a pain.

Sound quite good, though somewhat less dynamic than I'd like (into Wilson WP 7s). PS Audio P600 helped before I moved and got dedicated power outlets; then I didn't miss the PP. Plenty of bass. Compared to the Nuforce 9s which I replaced it with, the ARC sounded compressed dynamically.
Woodburger, thanks for your comments. What are Nuforce 9s? Digital?
Check out their site. Not really digital - I think analogue switched digitally.

As they say: "The Reference 9 SE incorporates an improved power supply board with a low-ESR capacitor bank. Further enhancements include a separate switching power supply for the analog front-end, ..." and from the 6Moons review: (this) "amplifier technology is based upon the principle that a power oscillator can be modulated by an audio signal to produce an amplified audio signal obtained with a reconstruction filter but without the bandwidth limitations of a fixed frequency carrier-based conventional PWM control. It uses a high-performance analog modulation technique and a close-loop control system. Therefore NuForce refers to its audio amplifier as analog switching amplifiers."

One of the more pleasant surprises I've had in this hobby .
Interesting. So it is better than the VT100MkII?
Okay, here's my experience
1. It gets hot, but not incredibly hot.
2. Soundstage is not it's real strength for a tube amp, a little forward, however its microdynamics are incredible in my opinion. I would call it relaxed and natural.
3. I have never noticed the fan noise really, unless there was no music playing
4. I have used it with wp-7. sonus EA-1, Revel Studios. It is not a bass fiend.
5. No reliability issues and I;ve owned this amp since they came out.

You say good bass is a MUST. As I see it, the Nautilus are not easy drivers in the bass, this isn't the best bass amp out there by far. For the prices this amp goes on Audiogon, it is a steal.... but if bass is a MUST, you are probably not going to be thrilled. Diana Krall yes, Stained, no.

thanks Chris!
The VT100 MKII is a "classic" amp. It is easily one of the best sounding amps ever made by ARC irrespective of price. I am using it coupled with the LS25 MKI preamp also. Its strengths include: dynamics, huge soundstage, midrange purity and beauty, and sheer musicality. It is also surprisingly powerful and works well even with difficult loads (maybe not at disco sound levels). In summary, the VT100 MKII is a music maker and is highly recommended.
Gmorris, thanks for your comments.
Could you help me to compare this two power amp VT100 mk11 and VT 130se. In term of the price performance of those power amp.
I owned the mk2 and mk3 if you can the mk3 is better sounding. Still very nice sound with mk2. A good amp if priced is fair. Runs warm as do all tube amps with power.
I owned the VT100 MKII and sold it. Due to the wackiness associated with setting the bias for this amp, I consider it a fatal flaw. You say you have a tech that lives near you. Is he going to come to your house, or do you get to pull the amp from your system, carry it to your car, drive it over to his place, wait for him to remove 5000 screws and monkey with all of the adjustments, then drive it back home, carry it back into your house and set it up again?? Think about it. This amp weighs 100 lbs.
Mepearson has a very good point. I just went through this exercise with my ARC D70. Luckily, my amp doesn't weigh as much as a VT100, nonetheless, as I watched my tech do the bias procedure and check balances etc., it occurred to me that ARC must have been plum crazy if they figured a layman could do this stuff!
Not only are there lethal voltages inside the unit where you must adjust everything, but it is clearly not a simple matter to get the amp biased and set up correctly and from what i know the VT100's are even more complex!
Without the knowledge and tools required to do this job, I would say that the layman is REALLY asking for BIG trouble if they attempted the biasing procedure.
My amp manual indicates that this can be done by any I said PLUM CRAZY!!