Lonely Raven… OK... so you want long-winded? here you go! ;)
I don’t know what kind of speakers you have or anticipate having.. but if you have a pair of “Lowther” type speakers, i.e. single, full-range, high-efficiency type drivers with No crossover – you “Need” a Torii. My brain could not “accept” what my ears were telling it, the first time my Torii was hooked up to a pair of these. Then I remembered a little blurb I read in one of Steve’s white papers about the Torii’s circuitry and how it actually delivers more power into higher impedances. In the Tori IV thread I started, Steve confirmed this again when I was asking about if the Tori IV retained this characteristic of the Torii III – cause I DO NOT Want to give up this trait in my Torii III – read on….. This completely explains what I have been experiencing… most of these types of full range drivers have rising impedance curves in the bass frequency range. My particular drivers, Audio Nirvana Super Cast Frame 12” Alnico’s impedance starts rising at about 200hz and reaches a peak at about 54hz according to the curve published by the manufacturer. And these drivers, powered by my Torii have “weight” in the mid-bass/power region that just about has to be heard to be believed. This is a sonic match-made-in-heaven. And not just in the bass region either. Piano, stringed instruments, voices, are “in the room”, scary real. And there is astonishing PRAT… transient speed, snap, resolution way into hearing slap-echo off the back of the recording studio walls, the performers amps humming, singer wetting their lips – we’re talking serious “rez” here. There are plenty of highs too… but not to the level and caliber you experience, with for example, a Heil AMT or good ribbon tweeter. This is not the Torii’s fault, this is the nature of full-range drivers. But you won’t notice this unless you do an A/B. But at this point, a guy is just “looking for things” – it’s not something you will ever “notice” when enjoying music played thru this combo. I know this sounds like a bunch of reviewer blathering.. but I’m hearing music I’ve owned for decades “for the first time”.
The Torii exhibits a bit of this nature with every speaker I’ve hooked it to so far – including my Martin Logan electrostats – yes… that’s right, the Torii will drive the Martin Logan’s. Not to the same volume levels as my higher power, solid state, muscle amps, but to a comfortable level. But the Torii mated with single full-range, high-efficiency drivers, no crossover is a step up into a whole nother league… sound that is “right there” with the best I’ve ever heard – anywhere – at any price – cost no object. I believe this “more power into higher impedance” characteristic of the Torii is also a common trait of OTL amps as well – which I have no personal experience with.. yet - but that is on my bucket list, since Transcendent Sound is practically in my backyard.
Anyway the nature of the Torii about power into higher impedances, is as I understand it, basically opposite of most amps. Especially solid-state amps, where the design goal, for whatever reason for the last few decades seems to be for the amp to deliver more current into lower impedances – I think the engineers call this a “true voltage source”, where if the amp will put out 100 watts into 8 ohms, it should put out 200 watts into 4 ohms (doubles down). Of course you have to look at the given drivers frequency response overlaid on its impedance curve to be able to predict how it will sound… but let there be no doubt, that the Torii “was made” for the crossoverless, single, full-range, high sensitivity type drivers/speakers.
Where the Class D Audio SDS-470c amp excels is with more conventional types of speakers(more on that in a moment). Of course, I’ve hooked the SDS-470c to my full-rangers…just to see how it sounds. And they have even more transient snap, “jump factor” and rez than with the Torii. But the full-rangers exhibit a serious lack of bass driven by this amp. Yep.. that’s right, the 25 watt Torii has more bass than the ubber power Class D… “on this type of speaker”. So though the full rangers have high power magnification rez and dynamics that will scare you when driven by the SDS-470c.. the whole balance of the sound is “off”… sounds too light, thin, forward, bleached out – no “flesh on the bones”.
On the contrary, the Torii just sounds so “right” and balanced top to bottom on the full-rangers.. it just can’t be denied – fluid resolution that will keep you up way past your bedtime on work nights listening when you should be asleep. Your spousal unit traveling to your listening room multiple times… “turn that down”… “are you going to come to bed tonight!”…. be prepared for relationship stress if you get a Torii and some high-sensitivity full-rangers.
Now… another combination that is in the same “OMG” league as the full-rangers/Torii combo, is the Class D SDS-470c and Magnepans. I have had a soft-spot for Maggie’s for decades. But as anybody who is very familiar with them, knows.. they can be a bit lacking when it comes to dynamics and “lively” sound. Though the newer models are much, much better than the older ones. Any who… I have a friend with a pair of 3.6’s… after I was able to finally “wrap my feeble brain” around the SDS-470c’s sonic abilities and my brain could accept what my ears were hearing, I called him up and said Stephen… you gotta hear this $695 amp on your Mags. So I picked up the little 20lb SDS-470c and tucked it under my arm and headed out. About 30 seconds into the first song played with the Class D driving his Magnepan 3.6’s… the party was over. He has now sold his big Pass Labs amp.. and purchased two SDS-470c’s(he has multiple systems). The SDS-470c replaced another well known, highly regarded solid-state muscle amp in my own stable also… but I’ve probably already done enough “name dropping” to ruffle feathers, so I’ll cease before making it any worse.
So… Lonely Raven, if you have or are attaining a Decware speaker or any speaker, similar in design concept to a Decware speaker… get the Torii – and never look back – you just probably can’t do much better than this combo – similar probably – but better – hmmm… hard to say. You might have to search a long time, and part with lots of $$ and endure lots of frustration along the way.
If you’re contemplating some other more conventional, multi-driver speaker with a crossover and a more common(i.e. lower) sensitivity that is not really compatible with a Torii… you might ought to give the Class D Audio SDS-470c a listen before you spend more.
I think Stone.. needs to hear an SDS-470c on his big party-animal Polk’s – and report back to us. I used to have a pair of 2.3TL’s myself…. They were/are a fun speaker – specially for high SPL events. I suspect the larger VMPS models might mate well with the SDS-470c also… and as I’ve recently experienced, it is “the amp” for Magnepans. I have another friend with 1.6 Maggie’s and the Class D brings them to life also, but the SDS-470c was a freakin’ revelation on the 3.6’s.
I also acquired a 1990’s vintage pair of Klipsch’s a couple months back. They have some issues… need the xovers rebuilt for one thing I suspect.. the 23 yr old caps are probably shot … and I probably need to replace the diaphragms on the tweeters and maybe the squawkers too. I hope to get to this project over the winter. I hooked my Torii to them and I think this could be another good match.. but the speakers had a terrible “awk”, cupped hands coloration in the upper mids/lower treble… xover issue is my suspension. Just haven’t had the time to futz around with them yet. Suffice it to say.. the Torii/full-rangers combo blew the Torii/Klipsch combo into the dust. And I know the problem Is Not with the Torii…
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