I'm using my Ren. Sig. Mk. II with Electrocompaniet Nemo monoblock amps (600 wpc @ 8ohms/1.2 khz @ 4 ohms) into a pair of SF Stradavari's & the sound is fantastic!
The Nemo's sound like very powerfull tube amps with a crystal clear (no glare) top end, a sweet, warm, lush midrange & bass to die for.
Once thought about selling it to open a slot in my rack as they are dual chassis, but what could I possibly replace them with?
Probably one of - if not the best tube pre amps ever made!
Thanks for your comment, Paladin. I guess noone but you use a VAC preamp with SS amp :-):-)
Based on the specs and your positive experience, I think it will work fine with any tube or SS amp.
Both VAC preamps are superb with Clayton amplifiers as well
I use M-300....sound is just superb....VAC preamplifiers are special in that they mate so well with most all SS and tube amps, especially VAC.
I can answer your question. VAC currently makes two preamps.
VAC's current best preamp, the "Signature Mark II", was formerly known as the Renaissance Signature Mk. II and is unusual for tube preamps in that it uses an output transformer. Output transformers on tube preamps eliminate the impedance mismatch issues that almost all tube preamps can have with solid-state amps, as well as eliminate the problems tube preamps can have driving long interconnect runs to amps. A tube preamp with output transformers is effectively like a solid-state preamp for purposes of output impedance - the VAC website says the output impedance is <150 Ohms from 20 to 20k Hz. It should be able to drive amps with 600 Ohm input impedances or less (mid 90's Rowland, professional equipment), which is to say that it will not have impedance mismatch problems and can drive virtually any solid-state amp. It likewise can drive very long interconnects without roll off.
VAC's other current production preamp, the "Renaissance Mk. III", does not appear to feature an output transformer, which would explain why its rated output impedance is listed as "300 Ohms" with no specification for bandwidth. It is likely the case that its output impedance into low frequencies is at least ten times higher, meaning that there will be low frequency roll off with certain solid-state amps featuring low input impedances (as a general rule, the output impedance of the preamp should be at least ten times lower than the input impedance of the amp at ALL audible bandwidths). The good news is that many if not most current production solid-state amps feature input impedances sufficiently high that there is no problem. That said, if you have a long cable run between your amp and preamp, you could very possibly face roll-off problems (as you would with 98% of all tube preamps - the problem is not unique to this VAC preamp).
Both VAC preamps are point-to-point wired, which is highly desirable and rare these days (for cost reasons, most manufacturers use boards). I love VAC equipment and have owned Renaissance amps for ten years.
...as a general rule, the output impedance of the preamp should be at least ten times lower than the input impedance of the amp at ALL audible bandwidths.
Raquel (Threads | Answers)
I'm happy to see Raquel specify the importance of ALL audible bandwidths. Many people mistakenly use the 10x output impedance in relation to a preamp's nominal output impedance, when in fact it's very important to consider a preamp's highest measured output impedance for application of the 10x rule of thumb.
Just waking up this thread in case more responders wish to share their experiences. I am considering a CODA 15.0 Class A solid state amp to be used with a VAC Signature Mk iia preamp with phono. Seems like the VAC preamp is good with most amps, but I was hoping to hear from someone with a similar amp/preamp setup.
I have a Vac standard Le that I've matched with a Coda model 11 100W class A. The Coda will adapt to a lot of units and will let the preamplifier introduce its own signature, which might be uncommon to class A amps. A real cameleon in my sense. My other pramp is a CJ Premier 16 and same thing, the Coda will just let it through.
I always thought my VAC was quite at par with the CJ in terms of soundstaging. It can pinpoint small instruments with a lot of a separation in the dynamics of instruments.And the Coda just follows.
The Coda is a beautiful machine. 100W is quite enough to drive a lot heavy loads, mine are Acoustat Spectra 44 electrostatics and it does it with ease. Does not run as hot as a Pass or a Plinius. This is just a fine long term machine. I will promise you this, the day you will get rid of it, maybe for something more of an upgrade, you will regret it after awhile, like most former owners do.
Paladin: I have an older VAC Phi Beta tubed preamp, your precursor; and Dev had a Signiture Mk ii; we both were paired up to Bryston 28sst mono blocks; at 1000 watts/per; and had great synergy; Dev ultimately stepped up for the VAC 450 tubed amps; which he is in love with; my happiness is pretty well met; and living within my finances...so the answer is the VAC matches well with impediance; and sound quality and reliability to almost whatever amp you hook up to it..If you have the VAC, you'll be enjoying great sound. If you want high power quality solid state; may I also recommend you check out the new Hegel H-30; it will work well as a stereo unit; not necessary to buy individual mono blocks; unless you have very ineffecient speakers...some positive reviews are forthcoming...but I'm in music heaven with my current rig...good luck
I, too, run a Phi Beta with Bryston 28B-SST2 amps and find the synergy to be superb.
The Signature MkII does indeed pair extremely well with a good number of SS amps. When I reviewed it I used it with Jeff Rowland's 501 Monos, and have used it with the Coda CS I believe, as well as Cambridge Audio Azur 840W's, and on the tubed side with the Moscode 402AU, Einstein "The Light in the Dark" and the VAC Phi 200's.
As aforementioned by others this preamp mates very well to a wide variety of SS and tubed amps.
I am currently conducting yet another review of a high profile SS amp with the Signature Pre MKII and the results are predictably superb.
Thanks for the feedback. One more question for D Schroeder and anyone else who might know: The CODA amps have a large disparity in impedance for input options>> Unbalanced is 50K Ohms, but Balanced is only 1,000 Ohms (frighteningly low for most tube preamps). Due to the VAC design, running balanced with the VAC Signature Mk iia Preamp into the CODA should theroetically be OK, but I was wondering if you tried both balanced and unbalanced into the CODA and heard any difference, either in sonics or gain.
Rtilden curious why you didn't look at the CP for the preamp?
Was it because of the desire for tubes?
Tobb: CODA has been working on a new top model preamp, the model 07, which replaces the 05. The timing of my system upgrade was this past Spring '12, and the new 07 preamp had not yet been released. While pondering options, I began considering tube preamps as well, especially since a few Audiogoners had told me of their great success with tube preamp with CODA amps. Well, I dove in, and I must say that I am exceedingly pleased with my Purity Audio Design Ultra GT. Yes, quite expensive, but oh so nice.
Before buying my VAC preamp, I spoke with Kevin Hayes about matching it with my SS Electron Kinetics Eagle 2a, a very high current 100wpc amp that I fell in love with at first listening. He read the specs and said it would be a perfect match. Was he ever right! Only when I upgraded to a VAC Phi 200 amp did I hear better sound from my system.
Call Kevin and get his opinion, he is totally reliable and honest, aside from being one of the nicest guys you'll meet in high-end audio.