I have the Vac Phi 110/110 and I share your enthusiasm. A fellow Audiogoner recently told me mine was the most transparent system he had ever heard. I have just auditioned Revelation Audio Paradise interconnects, and it's the first time the musicians have actually "been in my room". Mind blowing. FWIW, I have done some tube rolling with the KT88 tubes with some highly regarded tubes, and I've gone back to the stock Vac tubes. Substantially more extension and realism.
Just curious Tvad, what power cable are you using on the VAC power supply? It's funny you mention Revelation Audio because I was thinking of trying the Precept.
Fsarc. I own the PHI 220's and the PHI Master control 2.0 preamp. Kevin told me it would take around 200 hours to break in, so I gave it some time. However, during that 200 hour wait I cryoed my cabling and put it back in the system. The VAC never sounded as good as it had at my friend who owned the 110. I couldn't figure it out, it was aggressive, lacked bass information. Well, long story short, my friend and I swapped out my cabling and WOW! everything you say came true! I finally heard the incredilby musical sound I had heard at my friend's house. I was so thankful that no one bought them from me on audiogon as I had them listed for a month. I later found out from the manufacturer (Sonoran cables) that my cabling was destroyed during the cryo process, which by the way, isn't common, and that was why I couldn't hear the quality of the sound. It was so bad sounding, I repurchased my entire Krell system that I sold as I missed it. I will probably put all the Krell back up for sale as you described it right, the VAC is so engaging and gives you the performance in the room versus a good reproduction of a recording like so many other systems. I agree, this is the best tube equipment I have EVER listened to and I have listened to all the best like Audio Research, Manley, VTL, BAT (Bad Amplification Tubes), Jadis, and Kevin Hayes is by far the best designer of musical, engaging tube equipment out there. Someone needs to get a pair for review and get the word out. I hope many read your thread.
Fsarc, I am currently using a TG Audio 688 on the Vac 110/110. It's the best I've found thus far. I was very close to trying the Precept, but my audiophile dollars are being allocated elsewhere at the moment. I'd give the Precept a try, though. With the MBG you have nothing to lose. Please report back with your impressions if you do try it.
I recently purchased the PHI BETA 110 (sold the Phi stand alone 110 (which was fantastic in its own right, and VAC Ren preamp) - The integrated is unbelievable - control of solid state, magic of tubes. Dynamic, transparent, musical, you name it. The PHI line is Kevin's best work yet....and I am stumped as to how he will even better it!
All of VAC's stuff in incredibly musical. By the way, Kevin personally listens to product before it is shipped, WOW. How is that for personal service.
The word needs to get out on this PHI stuff, it's that good.
The Sonoran power cord is an excellent match for the PHI. Very musical with terrific bass extension.
The Revelation Audio Precept power cables are working extremely well with the 220s. Silky smooth, dynamic, and superb imaging/sounstaging.
I know system and speaker interaction will dictate indiviual settings, but my 220s are absolutely kicking ass when using the XLR inputs, set to Ultra Linear, 4-6 ohms impedance, and zero feedback.
Fsarc, you might try some Revelation ICs just for kicks. They really opened up my system. Something tells me I don't have my set-up quite right with my VAC 110/110 because it sounds distorted when running zero feedback, and I know this is what Kevin recommends. I'm also running Ultra Linear and using the 4 ohm speaker taps.
In my discussions with Kevin he advised me the feedback setting would be highly dependent on the rest of the system and overall sound preference. He also stressed that the amp will sound far better in Ultra Linear mode than Triode mode.
My amps have three selectable feedback settings. Even on the "low" feedback setting the sound starts to become a little veiled, less dynamic and dimensional, and is not as engaging.
I also have the ground lift switch set to "on".
I'll probably give the Revelation ICs a try since they also have a 30 day trial period. The AQ Sky have been a fantastic match (the best I've found) so the Revelation Paradise ICs are going to have to be REALLY good.
In this article
from the VAC website, Kevin Hayes discusses his design philosophy and specifically mentions that the Renaissance series of VAC amps are class A1. Now, I don't know if that applies to the Phi series. That would be a question for Kevin. But, I'd be willing to bet the Phi series amps are based on the same basic design theory.
Indeed- they are Class A1. This is from my Phi 220 manual:
"The Phi Beam Power amplifiers are unique power amplifiers, and the most power and detailed in VACs history.
Excellent linearity is achieved without resorting to loop negative feedback, for a more natural, dimensional sound.
A total of four KT88 are used in Class A1. Uniquely, each is provided with a separate DC heater supply to ensure that no undesirable couplings occur; only the intended ideal signal path exists.
The input circuitry of the Phi is derivative of the unique Williamson circuit, which provides pure, direct coupled, inherently balanced input amplification and phase splitting. Type 6SN7/5692 octal twin triodes do the honors.
Two superb VAC output transformer, interconnected in a way that allows high power to be delivered with the sonic purity of low power devices, provide superb voltage/current translation, allowing impedances from eight ohms to as low as one ohm to be driven.
The main chassis is machined from thick aluminum. The separate power supply allows e.m.f. fields, switching transients, and mechanical vibration to be isolated from the audio circuits.
The high voltage supply utilizes dual choke pi filtering for extremely low noise.
The Phi Beam Power amplifiers are designed not to the latest fad but to substance, for the highest possible sound quality. Time spent familiarizing yourself with this manual will be well rewarded."
Well, interesting experiment tonight. I went direct to the VAC Phi 110/
110 with the APL Denon 3910 and tried Zero Negative Feedback on the
VAC. Eureka! No distortion. Even though I had tried going direct to the
VAC with the APL, I hadn't tried it with Negative Feedback switched off.
I'm bittersweet though, because it tells me there is a mis match between
my First Sound Presence Deluxe II and the VAC, although the system
sounds terrific with the First Sound in the chain and with the VAC's
Negative Feedback enabled. Now, I need to devote some listening to
both variations to decide which is better.
Tvad, I thought you were gonna buy that TAD stuff, and retire from high end LOL. Guys I am still going nuts, as to which amp to get. The Cary CAD 211 Anniversary http://www.positive-feedback.com/Issue11/cary211.htm
or the VAC Phi. Any of you hear both?
Any of you hear both?
Are you serious? You KNOW you'll be the first in this audiophool community to hear both.
Man, thats getting old already, aarrrgghhh, and in my system too, huh? Tvad, ya put in the PW yet?
No PW yet. Hell, I've just discovered I can run my VAC Phi 110/110 with zero negative feedback running the APL direct, thus avoiding the preamp altogether. This is a whole new Pandora's Box that will require some exploration. No worries, though, I'll try the PW promptly.
I am not worried now, I bet you will be selling your pre soon anyway. heh heh heh
Not necessarily. The music has more "life" and body with the preamp in the chain. And, for some reason there is more HF noise (hiss) going direct with the digital volume control.
aaaaaaaahhhhhhhhhhhh oooooooooooohhhhhhhhhhhhh k
Tvad, I owned the phi 110 and the ren 70/70's - while the negative feedback may 'tighten' the high frequencies, I lost some of the air and what I would call presence with negative feedback. Sometimes it was even recording dependent. I am not sure what to tell you or recommend. I know in speaking to Kevin he will tell you its system dependent. Perhaps you have some A/C line noise on the digital side? Also, the more 'noise' I have removed from my system the cleaner the high end gets and no need for negative feedback.
Another idea is the sistrum stand as it helped the treble quite a bit. Less grunge. I am not sure but tubes can be microphonic and perhaps the sistrum stand is eliminating/reducing the microphonics in the tubes, thus creating better highs...
Personally, I prefer a pre-amp for the dynamics/headroom...but going direct has its advantages and some mfrs are better at the analog outputs on digital gear these days...
You could go with a phi beta integrated :), like I did and forget about a seperate preamp and negative feedback!
Good luck. Let us know how it goes....
Scotty333, thanks for your thoughts. Alex informs me the problem has
to do with the 35dB gain of the VAC phi 110/110 when going direct to
the amp, and with the amp in the zero global feedback mode. Alex is
fashioning a pair of adapters to correct this problem.
Besides the mismatch issue with the APL, there are sonic differences
between running the amp with and without negative feedback, which are
inherent in all tube amps. As you mention, with zero global feedback
the soundstage expands and the air increases, however one gives up
some bass punch. I like bass punch, so I often find myself listening to
the amp with negative feedback. When the system is run this way, the
addition of a preamp makes a profound difference in dynamics.
It would be nice to be able to "dial in" varying amounts of
negative feedback, but I'm guessing Kevin Hayes has determined this is
somehow detrimental to his design. It'd be interesting to know his
Tvad,glad you figured it out. I hope the adaptors work really well for you. I know on the 70/70 you could dial in the feedback, but on the 110 am not sure how much flexibility there is. It sounds like you are down to some really fine tuning of your system.
Do you use the RAL power cables as Fsarc does? I am using Sonoran cable as a power cable, but have found the Prana silver cable to be a really nice match recently with the VAC as an interconnect and speaker cable. So I am interested in the silver power cords by RAL (as the Prana are quite a bit more). I am waiting on a pair of Deva interconnect and speaker cable to be made for me as they are hand made cables. They were a really nice match in my auditioning. The new prana powercord is supposed to be really good, but comes in around $2k, which is more than I want to spend right now.
Scotty, I've been using TG Audio 688 power cords, and just recently
purchased two VH Audio AirSine cords to try on the VAC Phi 110/110
and my Hydra 4. I've had the Vh Audio cords only a week, so it's too
early to provide any feedback. I'm going to leave them in for a month
and then swap the TG Audio cord back in to listen for audible
The RAL are working out quite well. I'm also experimenting with the Running Springs Duke power conditioner on my 220s. I'm running a Duke for each amp on its own dedicated 20 amp circuit (on opposite phases).
It's funny you mention the AirSine as I might be heading to a friend's house today to do a comparison on the RAL versus the AirSine. Granted, it will not be on my system with the VAC gear, but it might be constructive nonetheless.
I definitely prefer my 220s on the no feedback setting. When I start to add feedback, the music loses a lot of air and openess. It is like a veil has been placed on my entire system. It is still very musical, but in the context of listening with no negative feedback, the shortcomings are readily apparent. According to Kevin, the use of feedback is system dependent so let your ears be your guide.
I also have a Phi 2.0 Master Controller on the way! We'll see how it stacks up against the linestage section of the Meitner/EMM DCC2. The Phi amps have a lot of gain and I'm using the DCC2 at the very low end of its volume control (25-35 out of 99) so I'm not sure if that is having a negative impact in any way. Plus I'll be getting a killer phono stage which will leave me no excuse NOT to get a vinyl rig!
Fsarc, wouldn't it be relatively easy for you and your friend to swap RAL
and AirSine cords for a week or so? Seems like this would be an ideal
way for each of you to try excellent new cords in your own systems?
Have fun with the Phi2.0!
Tvad- FWIW, I brought my RAL to my friend's house and compared it to the AirSine on his Tact 2.2x and the results even shocked him. Taking into account this was not a long term test, the results were readily apparent and immediate in favor of the RAL. The bass was tighter and quicker, with the AirSine sounding bloated and lagging behind the rest of the music. The top end was much more extended with a great sense of air around instruments and vocals. Overall, the RAL was extremely balanced from top to bottom and made his system sound much more musical.
My 30 day audition period of the RAL is coming to a close and they are not going anywhere. They have sounded fabulous in my system. The AirSine was top on my list to comapre against the RAL and I did that today. I know it was not in my system, but I heard what I heard. I plan on trying the RAL Paradise interconnect for 30 days against my AQ Sky. I like to do things one at a time....
Fsarc, considering the possible differences in synergy between tube and
SS, I thought it might be beneficial to hear them both in your system. I
respect that you've made your choice. Perhaps I'll walk the walk and
order a pair of RAL to compare to the AirSine.
I wanted to hear them both in my system also, but I have 4 RAL cords, and he didn't have at least 2 cords with 15A ends. We were going to introduce one AirSine into my system about 2 weeks ago when he came over, but he forgot the AirSine at home :-(
You really have nothing to lose with the RAL cords as even return freight is covered if you don't like them. Are you still using the Paradise interconnects?
Still using, and loving the Paradise IC. In fact, I may participate in the auction for the iPod interconnect.
FSarc, where are you going to post your VAC Phi 2.0 Master Control findings when you receive it?
Most of the gang in this thread has already joined the fun on a new thread that is helping me decide on my ultimate tubed balanced linestage: Vac Ren II, VAC Phi, Arc Ref 3, and the mighty Aesthetix Callisto are all in the running. If you wish to join, please visit us at
See you there! Guido
ANy contact info/website for Critical Mass Systems would be appreciated.
Here is some info for Critical Mass Systems. Joe Lavrencik is a great guy and has had some impressive CES showings with Joule-Electra, Elrod, and Vandersteen/Avalon. Steve Huntley at Great Northern Sound is also a big fan of Joe's work.
This platform is the bird's eye piece Joe did for me. I have four of them.
You should also consider products from Gran Prix Audio and Silent Running Audio.
Have any VAC Phi amplifier owners rolled the 6SN7 tubes? I'm presently using Sylvania 6SN7GTA, and someone recently suggested trying RCA VT-231 or Sylvania VT-231 to sweeten the top end just a smidge. Anyone?
To say the least I love my Phi 2.0 Controller and the Phi220. I have another amp which is hard to beat that being the CAT JL:-2 Signature Edition and there is still something magical with the VAC. The detail in the midrange and the subtlies using a killer cartridge and arm Like my Kuzma 4 Point and Da Vinci Virtu with the PP-1000 or the ZYX Universe II is hard to comprehend. You know that feeling that its like I am hearing my albums for the first time again happens every time the needle touches the vinyl for me. Absolutely electric! Don't see ever selling these. I actually have 2 Phi 2.0 Controllers I liked them so much. Silly me.