ARC VT-100 MK II vs. Sonic Frontiers Power 2

Hi K; I'll follow your thread with interest as I have not heard the VT 100 MK II, but would like too. I bought the Power 2 and used it for about 30 days in my system about a year ago. The Power 2 does tend toward neutral/accurate rather than "tubey" or euphonic. I thought it had a nice clear, non-fatiguing mid-range, but kind of soft bass. Soundstaging was OK, but not spectacular. But then I was comparing it to my long time standard McCormack DNA-2DX amp (now Rev. A).

The DNA-2DX is very fast with excellent bass (and mid-range too), and when I put the McCormack back in my system, it was "no contest"-- I preferred the DNA amp in all important aspects. That said, the Power 2 was a pleasant non-fatiging amp to listen with, and as I have an SF Line 2 pre-amp, I expected there would be good synergy between the Line 2 and Power 2. I'll be interested in seeing comments from those who have heard both the tube amps you ask about. Cheers. Craig

my impressions (strictly from reading the magazines) is that
the ARC is one of the best and most well rounded amplifiers made, and that the Sonic Frontiers, though competent, is somewhat uninvolving. Again, I have not heard either but read a lot of the trade magazines. I am trying to give a conservative view.
have fun

I owned the ARC VT100MKII and it is in fact a fairly neutral sounding amp. The low end bass and "slam" was outstanding and the air and soundstage was also very good. I tend to enjoy a more tube like sound though especially with a wee bit of midrange sweetness so I sold the ARC and kept my CJ Premier 11a. The ARC was almost "solid-state" relative to the CJ. On the other hand I preferred the ARC over my Classe solid-state amps.

If you enjoy tube rolling, be warned that the ARC VT series are not user friendly in this regard. Swapping power tubes is relatively straight forward. If you want to mess with the drivers, you better be preparred for some heavy duty disassembly, reading schematics, tweaking a handful of trimpots, and reading digital meters.

I have owned VT-100MKII and currently have SF Power 2.
SF Power 2, with stock tubes(Svetlana 6550Cs and Sovtek 6922s), sounds very neutral and does not have the warmth of VT-100MKII. But with different tubes, KT88s and other NOS 6922(such as Amprex, Phillips, Valvo, or Siemens) SF Power 2 sounds like a completely different amp, you will be rewarded greatly. It will bring the warmth of VT-100MKII along with more refined bass with better details/accuracy along whole frequency than ARC VT-100MKII.

Also I have experienced SF Power 2 being a lot less fussy and more reliable than VT-100MKII(retubing VT-100MKII is a whole story itself). ARC preamp works very well with SFP2 as well. If you are considering SFP2, make sure to select tubed preamp.
I have sold my ARC VT-100MKII once I retubed my SF Power 2 with KT88s(I have a set of Svetlana and a set of JJ Tesla) along with Philips 6922s(I have Valvo set put a way).

With NOS 6H23 6922 tubes the VT100MKII also sounds like a different amp. With these tubes the VT100 MKII equals the VT100 MKIII in terms of detail retrieval, midbass robustness and bass extension. However the MKII surpasses, easily, the MKIII in terms of midrange liquidity and musicality. Your comparison is skewed towards the SF. Did you try the NOS tubes in the VT100 MKII? I prefer markedly, the ARC to the SF. Again, observations are system and preference dependent.

Since posting this, I did get a Power 2. First thing I noticed is less immediacy and liveliness. Then I changed the tubes to KT88s, with a substantial change. Now, the sound is fuller and more dynamic, more immediate. It sounds part of the way toward the VT-100.

However, I still notice that high treble detail and air is less on the SF than on the VT-100. You especially hear this on cymbals, brushes, etc. The SF does sound a little fuller and more powerful, though, the VT-100 sounding 'leaner'. It's a toss up at this point, and I'll have to do further listening.

I do not find the SF "solid state" sounding, as some people say. With the KT88's, I don't find it uninvolving or bland, like others suggest. I do think, however, that the increased 'liveliness' of the VT-100 could be interpreted as increased "musicality" or "involvement" that other hear. Also, I don't find the SF bass to be inferior to the VT-100 by very much, if any.

So, does the VT-100 favor and emphasize the high frequency detail and air, or is the Sonic Frontiers lacking in these areas? Or is it just a matter of tonal perspective. I don't know. However, I think we need to keep in mind that no component reproduces sound perfectly. Every component has its sonic signature and its own way of presenting a facsimile of the musical event.

Kevziek,

Have you changed your input tubes?(6922 tubes). Sovtek 6922s are known to lack details in high frequency. Also are you using the SF Power 2 in Balanced mode or Single ended mode? What preamp?
I'm not finding lacking high frequency detail and air on my SF Power 2. Actually it is sometimes too detailed on some of the music(with the music recorded too bright).

Nameci, I haven't changed the 6922's. They are original from 1/99. I have been using the Power 2 & the VT-100 single-ended. I have a good balanced cable that I'm now using between DAC & preamp, so maybe I'll switch that with the single ended I'm now using between amps & Sonic Frontiers SFL-2 preamp.

What input tubes are you using? Balanced vs. single, your experience? Thanks.

Kevziek,

I have tried a bunch of KT88s and 6922s and some were pretty decent and others were not worth trying.

I'm now using Phillips 6922s with Svet KT88s for every day use. I have used Valvo 6922s with Svet KT88s for about 2-3 months and they are put away(saving them).

Definitely try tube rolling 6922s(since you already have KT88s, what brand are they? hope they are not Sovtek). There are 6 of them on Power 2's so start with reasonably priced NOS like Amprex or JAN Phillips(make sure to get JAN version). Also if your preamp is tubed and use 6922, try to match them with same brand 6922s as your amp.

I definitely recommend balanced operation on both SF Power 2 and VT-100. SF will give you slighly more extended in frequency with more details(which some people call "it solid state like"). VT-100 sounds warmer in single ended mode.

SF Power 2, tube rolling is a piece of cake. With VT-100, be careful.