Plinius SA102, single versus mono?

I couldn't wait. Hooked up both Plinii with an extension cord out to the kitchen. The extension cord fed an industrial 5KVA transformer, supplying balanced AC to the SA100's. Other gear included a Talk Electronics Thunder 3.1B CDP and a DIY TVC passive pre. The speakers are Genesis 350's with planar "ribbons" and their own servo bass amp with active crossover The room is roughly 16X30 with several DIY membrane bass traps. ICs are all XLR, mostly Nordost Blue Heaven.

As I said before, I wasn't expecting much. I was wrong. I've had or tried a couple sets of monoblocks with these speakers including Monarchy SE100's and Manley Snappers. The Monarchy's were from the previous setup. When I got the first Plinius, my first reaction was "natural" but it was a little laid back and polite which is typical for class A. It did everything well but in a Canadian character. I only know a couple Kiwis. Bridging them made them more American, but in a good way ;)

The first thing I noticed, and surprised me, was more upper midrange energy and a more forward soundstage. Still, it never got bloomy or as forward as many. Vocals and horns were more pronounced and cleaner. What wasn't as surprising was the added snap to the leading edges. Snare drums,in partcular, were more distinct between the hit and the rattle. There's a bit of Supertramp's "From Now On" that has the cymbals sweeping across the floor that I've never heard better. Formerly, the Monarchys were the imaging champs. Everything was a little better, more natural. Some subtle differences and some not so subtle. That's American, isn't it?

I decided to drag out my old Kappa 8's. They're power pigs, just like the 802's, and don't use that bass amp. Notice that I didn't say "don't need". I hope you appreciate this. We're talking about some heavyweights here. It was revealing to me too. I've been much too polite to the neighbours with the bass volume. What can I say, I'm a Canuck. After the initial shock of how lo fi my former beloved were (I've been spoiled by the Gennies) and the rotted-out hole in the surround, I popped in some Dire Straits.

Let me start by saying that you gotta love sensitive amps. I had this at one-quarter volume and Private Investigations rattled the doors. With an active pre and even moderately efficient speakers, these could fill a stadium. When I tried with one Plinius, I had to turn up the knob a few clicks to match SPLs.

One Plinius definately sounded thinner but don't ask me which is more neutral. The bass, either way, was better than I ever heard with these speakers. The character change was similar to the Gennies but harder to hear.

Funny thing is, I still have a Canadian-made Mission 777 amp (I got to get around to selling stuff) that was rude and crude but had incredible dynamics. It would assault you and slap your head into the chair. Dual Plinii aren't quite that aggressive, but close. Do it.

PS

All that talk about my Gennies makes me want a box of chocolates.

PPS

Find your Kiwi a mate (to be read with an accent)

Ngjockey,

thanks a lot for such an elaborate. It is more than generous to give such a broad description. Some of this is a well deserved tribute to your Genesis :-).
If my funds will allow I will extend the set-up to two monos.

In your opinion it is more vertical (bridging) or horizontal biamping when the difference is more pronounced?

Take care,

Thomas.

Greetings Thomaskatewitz; Ive had dual mono Plinius 102s for about 2 years now { serial #s 2173 in black/ and #1865 in silver}in my opinion everything stays the same, no harhness in tone, soundstaging remains intact but your micro and macrodynamics, because of increased power go through the roof, albeit pleasently.Everything that makes this a great amplifier just gets better and more pronounced, bass which has always been a strongsuit is simply fantastic with detailed drums, skins,kickdrums, rimshots and circular drum patterns as the artist works his kit very you- are-there- realistic with excellent seperation. Guitar strings with changing tone colors rising out of a dense sonic envelope all the while allowing you to focus on any part of the spectrum, no congealing .As for the midrange, its a in "the room presence" with any well recorded vocalists and especially so with unprocessed or direct to disc accoustic settings, thats not to say rock and pop are not worth a listen, just that it may have you searching for better recordings.

Vertical biamping with identical amps will make negligible difference unless severely underpowered in the first place. Bridging quadruples the total power and that will only increase by 6dB. Average listening is around 80dB. Vertical biamping will reduce intermodulation caused by reactance of woofer/crossover but, again, negligable. The only good reasons to vertically biamp is to:

1) Use different amplifiers, specialized for their purpose. But that opens up a can of worms (gain, impedance, linearity, phase ...). The Wisdom's active brain has been poo-poo'd for being too complex but there are several good reasons. Wasn't as much as a problem ten years ago when manufacturers tried to follow standards.

2) To eliminate or eviscerate those pesky passive parasites and replace with active crossovers. Even my expensive speakers use only semi-active crossovers.

In my system, the Plinius amps were used in balanced and bridged mode for both sets of speakers. The Genesis "stealth" amp is vertically biamped and proprietary. For anybody reading this that is unfamiliar with the Plinius, it has a rotary knob on the back to select either RCA stereo, XLR stereo, RCA mono or XLR mono (differential). For the bridged modes, both positive speaker terminals are used.

Horizontal biamping is a term I don't like, even when bridging stereo to mono. Logically, there really shouldn't be any better imaging and channel separation but the Plinius leap-frogged in that respect. The drawback of bridging is that it is similar to reducing the load by half. Also, many, if not most, amps just don't sound as good when bridged. They are specifically built to sound the way they do as they are. If they wanted monoblocks, they would have built them and charged four times as much.

This is where Plinius deserves the tribute. The Gennies are a steady 4 ohm but those Kappas dipped down to 2 ohms at 90 Hz. To actually sound better (and not release their smoke) under that difficult load when bridged is a credit to their designer.

I've had some more time with the mates and I'll reaffirm what I said earlier. They're not rude but completely unapologetic. For a while, I thought I had a compatibility problem with the bass amp. Turned out to be that I had listened to too many live albums in a row. They close-miked the bass drums and I was getting more subsonics than bass. My chair was rockin' and I barely heard the drums. It's not a rocking chair. I'll say sorry to the neighbours later. Screw it, I'm moving.