VAC sigma vs Vac phi 200.


Need inputs from experts.

I am thinking of buying one of this amp.

I already have ARC ls 17. which one do you think has better sound?

1. Vac Integrated Sigma 160i or
2, Phi 200 with LS17 as preamp.
aprica88
Hi - I am also contemplating the same question, and heard both amps in a high quality demo.
The integrated was making amazingly good music, and sounded more powerful than its nominal 80w.
The Phi 200 amp sounded clearly superior sonically (more oomph, clarity, definition, control, ...), it's probably the best amp I have heard in combining musicality of tube amps and clarity/control usually reserved to good solid state amps. The funny thing though is that this still left a bit unsure, I was not 100% clear if I was getting more emotion and pleasure through the better amp. Go figure!
Associated speakers were the new Magico S1.
One thing is for sure: both amps sounded great, and VAC really deserves more recognition for its products.

[I also could hear in comparison the ARC REF 75 and 150, and stopped after only a few minutes to go back to the VACs. Way more musical and "real sounding" to my ears.]

Fplanner2000, can you please clarify what you mean by better components and no IC with the integrated?

Thank you.
How do you connect the LS17 with the Phi 200? INTERCONNECTS. Interconnects in the signal chain have potential to add distortion, noise, etc., etc. Are also an added expense and a potential limiting factor in your system.

Which preamp/linestage is better? LS17? No; Built into VAC? YES. Also better synergy VAC:VAC.

I have a good friend that has the Sigma 160 integrated and loves it.

Hopefully this explains my comments a little better for you.
As a VAC owner (Renaissance 70/70 MkIII), and based on many comments I have read, I'm sure they are both exceptional products. Here are some additional factors that you may want to consider, though, in choosing between them:

1)The Phi 200 is spec'd as having a gain of 37 db single-ended, and 31 db balanced. Usually, although not necessarily, if the two numbers differ the balanced gain will be 6 db higher than the single-ended gain. I would check with Kevin at VAC to verify that those numbers are not reversed. See the next paragraph for the possible significance of that.

2)If you were to use the Phi 200 with your LS17, I suspect that you would want to use balanced connections between them (see, for instance, the comments about balanced vs. unbalanced in this review of the LS17). If the balanced gain of the Phi 200 is 37 db, which is quite high, and you are using digital sources having typical 2 volt or so outputs, you may wind up with excessive overall gain, causing you to operate the preamp's volume control very low in its range. That might still be true even if the gain is 31 db, given the 18 db balanced gain of the LS17.

3)The gains specified for the 160i appear to apply to its phono stage. You might want to ask Kevin what the gains of its line stage and power amplifier sections are, especially if you are using digital sources.

4)Concerning degradation of the sound by the interconnect cables that would be needed if you were to go with the Phi 200, there are several tradeoffs that are involved. Depending on how your components are physically arranged, using a separate power amp may allow you to use speaker cables that are shorter than if you were to go with the integrated. The lower the impedance of your speakers, the more important that would tend to become, and the higher the impedance of your speakers, the less important that would tend to become. The sonic effects of the interconnect cables will tend to be lessened if they are balanced, and will tend to be moderated by the fact that the LS17's output impedance, although not particularly low, is well within reason for a preamp having a tube output stage.

Good luck in your quest!

Regards,
-- Al
One more point to consider:

5)The Phi 200 provides three output taps, while the 160i provides two. Having the additional tap provided by the Phi 200 might be sonically beneficial with some speakers, particularly those having very low impedances, and possibly also with some speakers whose impedance varies widely as a function of frequency.

Regards,
-- Al
Thank you for your info.

I think I might go for the Sigma.
The Sigma has really good reviews from users and reviewers. There are not many of them willing to sell used VAC amps. These might indicate SATISFIED Vac users.

Also, Not much cabling needed and easier to set up.