Sand_Man:
I am glad you are enjoying the Model 6's. I ran those amps for three years and regret selling them. Some friendly advice:
(1) Try to buy the battery power supplies, as they were voiced with batteries and sound best that way (Model 6's come up for sale on A-Gon as often with batteries as without, and someone will be willing to sell the batteries separately). The amps produce objectively less power with the batteries, but subjectively sound like they have more headroom because you can turn them up quite a bit louder before the sound falls apart due to noise (higher volume also magnifies A/C line noise, and the difference with the batteries is not subtle). I suggest that you read Stereophile's multi-part review of the Model 2, which contains a section devoted to how the amps sound with the batteries.
(2) While they work fine when run single-ended, run them balanced, as they were voiced in balanced mode and sound best that way.
(3) Regarding what preamp to run with them, I don't know what your budget is, but I would look at a top differential balanced preamp. The safest bet would be a Rowland Coherence II Mk. 2 (disclaimer - this has been my main preamp for the last five years) and a Synergy IIi would also be very good. The Levinson 32 would also likely work well, although I am just guessing. All of these pre's are quite pricey, though. As for balanced tube preamps, I am against the common wisdom as to tube preamps generally and prefer top solid-state due to noise issues and the problems most tube pre's have driving longer interconnects, but if you must, I would try to find an Audio Research LS-5 Mk. III (some feel it is the best sounding preamp ARC has ever made), ideally turbo-charged with new capacitors and higher-shelf tubes. Ralph Karsten's (Atma-Sphere's) top preamp or the better BAT and Audio Research balanced tube pre's are also obvious contenders.
No offense intended, but your c-j PV10 is essentially a mid-fi component (I know it well) and is really holding you back.
Enjoy your Model 6's -- they are spectacular amps that layer sound like a top tube amp, yet are extended at the frequency extremes and have some of the highest resolution available from any amp technology. In solid-state, only the darTZeel is better to my ears. |
Sand-Man: If you have a budget, forget the Levinson 32 ($8k-$10k used). I think your best option is the Synergy IIi.
Enjoy. |
Sand Man:
My only hesitation about a tube preamp is what I previously mentioned, which is to say, the inability of many of them to drive long runs of cable and impedance mismatches with amps (this is mostly a problem when they are paired with solid-state amps, which tend to have much lower input impedances than tube amps). The ARC LS-5 Mk. III has a fairly low output impedance for a tube preamp at 400 Ohms on average and the specs indicate it will work with an amp having a minimum input impedance of 20,000 Ohms. However, the impedance likely rises in the bass. The Model 6 provides a choice of 600 Ohms or 18,000 Ohms input impedance. Especially with long interconnects, there is a chance that you could experience some bass rolloff. This is not a reflection of a lack of quality -- some really high-end balanced tube preamps, like the Audio Research Reference 3 and BAT 52, are worse. Regarding the Audio Research Reference 3, John Atkinson wrote:
"The output impedance was also to spec., at 635 ohms balanced and 326 ohms unbalanced in the treble and midrange, but rose to 1437 ohms and 625 ohms, respectively, at 20Hz. This rise in source impedance rolled off low frequencies a little early into the punishing 600 ohm load (fig.1, bottom pair of traces), with a 3dB frequency of 17Hz. As this is a relatively low frequency and the preamplifier will never be used with a power amplifier having an input impedance as low as 600 ohms, this rise in source impedance will not be a factor in practical use."
In fact, Rowland amps have impedances typically seen on pro gear and you can in fact choose a 600 Ohms input impedance setting (which would work best with a Rowland preamp). The Rowland Synergy IIi, preamp, for example, has a balanced output impedance of 80 Ohms -- it will drive anything.
While you would likely be fine with the LS-5 on the Model 6's (set at 18,000 Ohms input, of course) and I would try it if I were you unless you have really long runs to your amps, the Synergy IIi is a risk-free choice. |
I cannot speak to the differences between the two, but I would wait for a IIi if it were me. |
Not to pile on in this thread, but I ran a CAT preamp for several years (not with my Model 6's, however), and it is a truly excellent preamp. That said, it is single-ended, not balanced, and it has a ton of gain, meaning that, with a sensitive amp, you are not going to have much play in the volume control (i.e., if you turn the volume up just a little bit, your system will be really loud, and, each click of the volume control gives you big jumps in volume). I sold mine because, with my VAC amps, "9 O'Clock" gave me tremendously loud volume and I only had 5 or 6 "clicks" total range on the volume control. CAT could retrofit the preamp to have less gain, but I was told point blank by Marty of CAT that it was not an ideal solution and affected transparency. The CAT preamps have 26 db. of gain, while most have only 8-12 db. - why CAT chooses this gain architecture is beyond me.
Two other things about the CAT that are less than practical: the power supply is hard-wired to the preamp by an umbilical cord that is stiffer than (and nearly as thick as) a bridge cable, and both are heavy as hell -- installing it was either difficult or nearly impossible in my systems. It also has no remote.
Ken Stevens builds an excellent preamp that includes an excellent phono stage, but like his extraordinary amps, they are not long on practicality. I would definitely go with an equally good competitor that is balanced, as the Model 6's sound best when run balanced. |
I'm glad that came up -- it is not "green", but you definitely want to leave these amps powered up 24/7. And I'm not talking about leaving them in Standby -- I mean full-on, 24/7, except when they are unplugged due to electrical storms. If you do anything else, you greatly increase the risk that they will break (thermal cycles that occur as a result of turning things on and off are what makes transistors or small-signal tubes die over time), and you are wasting your money on performance that they cannot deliver due to the time needed to reach thermal stability. If you run mid-fi gear, a tube amp or a Class A-biased solid-state amp that guzzles tons of electricity and roasts your room, that's one thing, but a very high-end Class A/B-biased amp should generally be left on 24/7, as should, as a general rule, all of the rest of your gear, including all tube gear except tube amps (the output tubes on a tube amp wear out quickly if left on 24/7 because they pass a lot of current, but small-signal tubes usually pass little current and generally last much longer if left powered up 24/7 -- the studies done in the 1950's proved this incontrovertibly). |
Sirspeedy:
ALL equipment, each component, has to be unplugged from the wall to protect against electrical storms -- turning things on and off provides no protection. You can put antisurge protection at the subpanel and elsewhere as an alternative.
Sand man:
My opinion is that current production Rowland components are not the equal, in terms of sound or build quality, to his all-out designs of the 1995-2000 period. The parts quality has dropped significantly, which is reflected in the much lower prices (inflation adjusted) of his current gear. Gone are things like separate power supplies ("Why did these idiots make this thing in two pieces? My home theater installation guy is telling me they won't fit on the shelf"), and I don't believe that either of the current production preamps are truly differential balanced, a much costlier design that requires twice the number of parts. At some point, a decision was made to produce higher-margin products aimed at the B&O / high-end home theater crowd (take the 201/501 amps -- he is charging $4k/$6K for a pair of ICe modules that cost $750/$1,500 in a fancy case). In short, the Coherence II / Synergy preamps and Model 2/6/8/9 amps, all designed in the late 90's at the height of the two-channel boom, represent the pinnacle of Rowland production and sound quality.
If it were me, I would be looking for a Synergy IIi and the Model 2/6 battery power supplies that Rowland has retrofitted for use with the Synergy IIi. |
Drubin:
I found the 10/12 to be open and quick, but lean sounding -- I prefer the 2/6/8/9 sound, which is more burnished in the mids.
Jmcgrogan2: We don't disagree. I wrote that there are alternatives, but I did not mean better alternatives. My drafting error.
I ran a Hovland with my Model 6's for about a year and got very good sound, but, as noted above, I prefer very high-end solid-state preamps over tube preamps -- the very best ones layer space every bit as well as the best tube preamps, but they have lower noise floors (crucial in high-rez systems) and can drive any length of cabling. I do have a preference for tube amps over solid-state, however, as they almost always layer space better and have, to my ears, a more life-like presentation than solid-state (an exception to this statement is the amazing darTZeel).
Regarding the other preamps mentioned, the Kline is not balanced, is it? BAT certainly makes fine gear, but I do not like equipment that uses 6H30 tubes because there is only one manufacturer and your stuck with that sound -- does the BAT VK-31 use a different tube? If you must do a tube preamp, the Sonic Frontiers Line 3 is well built and has a nice remote. Chris Johnson, a former principal of Sonic Frontiers and now owner of PartsConnexion, has a lot of integrity and is a pleasure to deal with -- he can help you with tube selection. In addition to the LS-5 Mk. III, any of the Audio Research Reference preamps that do not use the 6H30 tube will provide excellent sound, as will Ralph Karsten's (Atma-Sphere's) top preamp. If it were me, however, I would be thinking Synergy IIi (or budget permitting, the Coherence II Mk. 2 or Levinson 32 -- they may be the best solid-state balanced preamps available).
For whatever it's worth, I run a Coherence II Mk. 2 (and Cadence phono stage) with VAC Renaissance 140 Mk. III zero-feedback triode monoblocks. |
SirSpeedy:
Does turning equipment on and off damage it? Over time, yes, some equipment more than others depending upon how hot equipment gets, as the hotter a piece gets when powered up, the more expansion and contraction occurs when it is turned off and cools down (it is expansion and contraction that causes components to fail over time). Leaving equipment on 24/7 does subject the caps to additional wear, as a cap is smacked around by alternating current waveforms (hence the term "A/C") whenever power flows to it, but good caps last many years even when seeing power 24/7 and are easy and relatively cheap to replace. The other parts of a component are not necessarily easy or cheap to replace, however, and the best way to protect them is to keep them at a constant temperature. People think that solid-state amps are easier to own and more "reliable" than tube amps -- wrong -- ask Krell and Madrigal amp owners that question after they lose transistors and then discover that the transistor is no longer made. In this regard, the riskiest component to buy used is probably a solid-state power amp -- most people turn them on and off, and after a number of years of being "pulled in and out of the fire", so to speak, some internal components have literally become brittle (a tube amp, on the other hand, essentially becomes a "new" component when it is retubed). Ask any honest tech who works on these things (the dishonest ones will say "turn it off", as it helps keep them busy). Manufacturers will tell you the same off the record, but often say "turn it off" in owners manuals because of liability concerns. Others want you to have best sound and most reliability, and do not include an on/off switch at all -- when the component is plugged in, it's on. Some components have to be turned off or can be more safely turned off. For example, tube amps must be turned off because output tubes pass a lot of current and last longer if powered down when not in use. Class A-biased solid-state amps burn a ton of electricity and heat up a room when left on constantly, as well as go out of bias too quickly. A component using small-signal tubes (preamps, DAC's, etc.) can be turned on and off if it also uses tube rectification, as the tubes in the power supply bring voltage up to the other tubes very gently, but most tube gear uses solid-state rectification, which is the biggest reason why people are constantly, and unnecessarily, replacing small-signal tubes (at power-up, the voltage applied to the tubes is like a kick to the groin).
All of that said, if you feel that you have to unplug your equipment to protect it against electrical storms, then you have to unplug your equipment -- suddenly running a few hundred thousand volts through your equipment is an extreme example of the deleterious effects of thermal cycles. |
When plugged into the wall, the input circuitry of the Model 2/6/8/9 amps remains powered up, but you have to engage the button on the front of the faceplate so it glows pale orange for voltage to reach the caps and the output transistors. The Model 6's run quite a bit warmer when fully powered up, meaning that they see significant temperature variations depending upon whether they are in Standby or full-on -- it is such thermal cycles, i.e., changes in temperature, that you want to avoid (not to mention that it takes a few hours after full power-up for the amps to sound their best). |
Sand man:
Woh woh ... time out. Why would you turn off your other sources? Your Electrocompaniet CD player could take anywhere from a day (some tubed DAC's) to a week (Naim) for the unit to stabilize after power up. Your c-j will sound much better and the small-signal tubes in it will last much longer if you leave it powered up 24/7. The combined draw off the line from those two components is only 30-40 watts. Put another way, it makes zero sense to be running vintage Rowland gear if you are running your source components from cold! When you are not listening, just turn the volume all the way down and engage the Mute on your preamp. Simple. That's how it's done.
The noise you are hearing is something in your A/C line (which can be mitigated or eliminated), and a bit of transistor rush (normal, and nothing can be done about it). The cheap way to cut down on A/C line noise is to make sure that there are no halogen lamps, dimmer switches, refrigerator motors, etc. on the same "side of the bar" on your sub-panel (an electrician knows what this means), and to make sure that all of your audio gear is on the same side of the bar. An electrician can move the lines around on your subpanel to achieve this for modest $$. Of course, running the Rowland batteries will achieve superior results.
In any event, if you are going to leave anything on 24/7, make it the preamp and CD player. Turning this stuff on and off is a good way to make it sound like Adcom/NAD (actually, worse, as Adcom/NAD gear can be quite enjoyable if used properly). |
Tiff Needle:
Congratulations on the Model 6's with batteries - they are superb amps. Jonathan Tinn, who is the U.S. distributor for darTZeel and a former Von Schweikert dealer, used to suggest Model 6's for Von Schweikerts if his customers couldn't afford darTZeel. The short answer is "any really good speaker" because the Model 6's are really good amps (like in "better sounding than most current production top-shelf solid-state amps").
As for general observations, I would have the batteries replaced in the BPS units so you don't have to worry about whether they are in good shape. I'll send you an e-mail with the battery information sent to me by Kelly Ballard of Rowland. Rowland buys them from Allied Electric in Ft. Worth and any decent tech can install them for you. The batteries are good for four to six years, depending upon usage. My experience with both Model 6's, which I owned for three years, and the Coherence II preamp, which I've owned for nine years, is that the Panasonic (Matsushita) batteries are the best quality.
In really good systems, the advantage of the batteries is that, despite reducing wattage somewhat, they actually give greater headroom because the noise floor remains much lower.
I strongly suggest that you leave the amp units powered up 24/7 instead of putting them into Standby. Standby cuts power to the output stage and exposes the output transistors to harmful thermal cycles. The amps also sound a lot better when left on 24/7.
Finally, my experience is that they sound really good when run without batteries, they are superb when run with batteries, and they sound best when run with batteries and fully differential balanced (you have a Synergy IIi, so balanced is possible for you).
I ran my Model 6's with Revel Salons (original version) - my Salon dealer thought highly enough of the Model 6's that he suggested them for the Salons, even though he wasn't a Rowland dealer. They are superb amps, especially with the battery power supplies - congratulations again. |
