David Berning Quadrature Z or Vitus SS-101

I've been using a Vitus SS-101 for some time and it's certainly a fantastic amp. I've been wanting to try a great tube amp that's not sloppy in the bass and i've negotiated the purchase of a David Berning Qaudrature Z. I will a/b test on my system and sell the one that loses the shootout. Any thoughts on what's the better amp?
I doubt too many can help with your inquiry. In any case you´re going to get you answer soon enough. I wish I were so blessed as to have such products to choose from. Please do keep us posted of your impressions, I´m sure many will be paying attention.
I've not heard the Vitus but had the Quadrature Z in my system for a week or so. The Berning amp has the vitality, transparency and illumination of a fine OTL. (Won't debate whether it actually *is* an OTL). It revealed layers of harmonic nuance - I liked to say you could tell that Dusty brushed with the Ipana, not the Colgate. Taut, tonally fulfilling bass. Easily the fastest amp I've ever heard. Good luck - the comparo should be a lot fun and I'd like to hear your assessment.
I heard the Berning in another system. I thought it became congested during large orchestral passages. It also made too much background noise. Something to consider in your own system since this is typically overlooked on a short-term A/B demo. If you don't listen to orchestral music and are not sensitive to noise, then you may like it.
Rtn1, your comments are very interesting to say the least. I have never heard either of your observations attributed to the zotl amps by Berning. Must have been some other issue. I own the zh270 which is less refined than the quadratures and the amp is neither noisy nor does it congest large music passages, to the contrary. It is both quiet and able to unravel complex music while maintaining scale. I would be most interested in the system and more of the details.
I have to concur with Tubegroover. I have Quadrature Z's driving Soundlab A-1PX speakers and the amps are dead quiet and never sound congested. I can't comment on the Vitus as I haven't heard it.
06-20-11: Rtn1
I heard the Berning in another system. I thought it became congested during large orchestral passages. It also made too much background noise.
What were the speakers being driven? And what was the preamplifier?
thanks for the feedback everyone. darkmoebius, source is lyra titan I, spiral groove centroid arm, spiral groove table, lyra erodian step up transformer into air tight ate-2 phono/pre

speakers are loiminchay kandinsky w/ TAD compression drivers.

06-21-11: Davidhyman
darkmoebius, source is lyra titan I, spiral groove centroid arm, spiral groove table, lyra erodian step up transformer into air tight ate-2 phono/pre...speakers are loiminchay kandinsky w/ TAD compression drivers.
Truly, truly, amazing system! The look/design of Kandinsky's speakers always blow me away. I've heard a system with the Air Tight ATE-2 loved every second of it. Is there any particular reason why you aren't considering Air Tight amplifiers?

BTW, I was actually addressing my question to Rtn1 to get a sense of the system context where he heard the Quad Z sound "congested" and with "too much background noise".
dark, i probably should consider air tight amps.

i guess the appeal to me of the berning is that it's going to have very tight bass compared to most tube amps and in my room, even with ample low frequency acoustical treatments, it borders on "wooly" - which is fine. sounds like live music. but a traditional tube amp can tilt it the wrong way.

the berning, with its ability to control the amount of feedback/dampening, allows to couple the woofer without over or undershooting the woofers. you can really dial it in!
in my room, even with ample low frequency acoustical treatments, it borders on "wooly"...the berning, with its ability to control the amount of feedback/dampening, allows to couple the woofer without over or undershooting the woofers. you can really dial it in!
Now, I understand. That could seriously come in handy.

Have you ever tried isolation speaker stands? Some do a great job of tightening up bass. In your price range, you could go directly to the best and just get Vibraplane Active vibration control platforms used in scientific and precision electronics manufacturing. There used to be, or may still be, an audio company who simply rebranded Vibraplane products and sold them at a nice markup.

Townshend Audio has a new generation of Seismic Sink stand that handles up to 350 lbs. Here's an Enjoy The Music review of the effectiveness of the last generation stand:
As with the 3D Sinks, the first challenge for the Townshend platforms was at another location. (I seem to have an abundance of friends with loose, springy wood floors.) The Von Schweikert dB-100 loudspeakers that I recently selected for a Best of the Year award were sitting on a floor that had all the stability of of a carpet-covered trampoline. On that easily excitable surface, the prodigiously deep and precise bass I had experienced with the dB-100 had morphed into a swollen, overblown mess. With or without spikes, the wild and woolly bass output was obscuring this loudspeaker's overall balance and detail resolution.

The 2D platforms were exactly the right solution. Placing the dB-100s on them restored the speakers' real character. The visceral deep bass now had the speed and clear pitch definition I had heard during my review process. Moreover, in addition to cleaning up previously obscured midrange information, the platforms also brought a new delicacy and sweetness to the high frequencies. A clear win for Townshend.
Also, here's StereoTimes review:
I first auditioned the Speaker Platforms in my 19' × 17' converted-attic bedroom loft to test response on wooden floors, and also to test the 3-D Sinks when placed on large very heavy, record cabinets (1500 LPs each.) First speakers tested were an old pair of Infinity Qb's circa 1976, pre spike, pre-speaker stand. Placed on spiked stands, the sound was thuddy and blurred in the bass with a notable upper-midrange edge. In came the Platforms. Can you say "Transmogrify?" "Apotheosis?" I now can.

Delineation of bass playing was particularly notable. What had been, without the Speaker Platforms, murk, mud and thud, was now agile, tuneful bass clarity. The clarity extended throughout the entire frequency range - pianos no longer clanged and note articulation and timbre were not shamed by the sound of the live piano that often wafts up the stairs. Vocal intelligibility was simply stunning: I was able to parse foreign lyrics into words and phrases even when I didn't speak the language. There was a sweet clarity, a lack of edge and harshness to the sound that I had not thought the speakers capable of producing.

There was also the unavoidable impression that the volume level of lower bass response was down a bit, along with some loss of resolution. Playing at loud levels showed the sound holding up even under the duress from hard transients and huge masses of instruments hitting crescendos. The speakers remained clear and focused and did not turn harsh. And for the first time from these speakers, I heard a huge, coherent, three-dimensional soundstage that extended the boundaries of my room.

Audition of the Spendor 2040 and Celestion 3 speakers showed the same loss of bass level. The trade-off was one of quality with the Sinks versus quantity without. Since the bass playing was so articulate and tuneful, quality eventually won out. The lower reaches of acoustic bass and drum thwacks were however, missing and re-positioning the speakers to see if a closer proximity to the speaker's rear wall might bring back the missing low bass was stymied by the room's lack of positioning flexibility.
EquiRack makes a new approach to isolation that seems to work extremely well on components and speakers. Each pod can hold up to 48lbs, so I don't know if four will fit under each of your speakers. But, check the reviews on how well they work
i've thought about that. i guess my only concern would be raising the positioning of the tweeter relative to the listening position. it took many days of measurement to get speaker placement right. the speakers dispersion characteristics are not awful but not great either. i'd probably get some high frequency roll off if i jacked the speakers up more than an inch from where they're at now.
Nothing a few coasters under your chair or couch legs won't cure...;o)

My speakers use 106dB Fostex T900A. Overall, positioning of the double-horn speakers and dual subs was an arduous task that I am in no hurry to repeat.

The manufacturer, the late Terry Cain, suggested I use a cheap laser level for construction to properly set angle in the vertical range towards my listening height. It worked pretty well.

Might be a little more difficult with your speakers due to their sheer weight and the level would have to be fixed in the horn mouth with some plumbers putty, etc.

I'd guess you'd have to fix a piece of art board in your listening position. Then, set the laser levels in the horn mouth and mark exactly where they hit the board. After placing the speakers on the isolation device, adjust the speaker and raise the rear spike until the lasers hit the spot again.
hey, seriously good point on raising the chair!!! never ever thought about that. that's genius!!!
From the pictures of your speakers, it looks like your room carpet on cement slab, is this true? Or, is your floor suspended wood?
I would agree, many of us wish we had your problems Dave. This gear is out
of many, many folks realm altogether, including mine. Tough one, you
already like the Vitus.

Yet what is the same for most of us is tweaking the set-up of the kit and
figuring out the sometimes (most times) elusive synergy conundrum. Many
foundation things will undoubtedly better a situation yet, sonically dead
cement floors and heavy speakers, sounds pretty optimal to me. My money
would go elsewhere in this case, like more vinyl.

To me though, no other amp will portray the speed, texture, and transparency
of OTLs with the appropriate speaker marriage. I have been around and
owned Atma-Sphere OTLs for well over a decade and find the sound qualities
addicting and irreplaceable with little to no short comings. I would have to
believe from all that has been offered here on AudioGon about Berning, it is
much the same thing. Do you find that the tube vs. semi-conductor
difference alone, regardless of bass for the moment, is more satisfying overall
or maybe difficult to discern? For me, that was my first big step and smaller
things were dealt with in their turn.

Fundamentally, if all other things are right with the music, it is down to which
flavor is for you. No other set up with different speakers or amps will tell the
same story, only similar. I think ultimately you have to decide for your ears
Dave, which amplifier gives you the most sound qualities you're looking for
with the Loiminchay Kandinsky pairing and then move on to sort out the

I hope you have the grace of time, as this sounds like a definitive step in the
overall sound of your system.

Happy Listening!
FYI, David Berning doesn’t do a lot of amp building these days but his amp designs can be purchased at Linear Tube Audio. He works closely with Mark Schneider to build these amps on a larger scale and more affordable.
this thread
at least for me
is extreme reinforcement to chase those passions NOW !!!!

RIP dude
Hi guys, I'm considering to get the DB Quadrature Z for my Maggie 1.7i. I know it's probably an overkill for the small Maggies but the 1.7i are the biggest panels that can work in my small 180 s.q. room, I started with 1.6 then traded up to 3.6 which simply over-energized the room, so switched back to the smaller 1.7i.
Anyway my biggest hesitation is the DB amps' reliability because if anything goes wrong I doubt anyone here in Hong Kong know how to fix it. Can any long term user share his experience living with the Quadrature Z?? Thanks a bunch!!
I have owned David Berning’s ZH230 and now own several Linear Tube Audio amps (David Berning designed) and can say these are probably the most reliable OTL types ever made. I would suggest you try the LTA ZOTL40 to use with your Maggie’s. Get them as 80 watt mono blocks and you will be rewarded. I swear these amps were made electrostats. The synergy is amazing and then add in all of the possibilities with rolling EL34 tubes. I have a pair of Janszen’s and a ZOTL40 with NOS Mullard EL34s and I would add to use the MZ2 as a preamp for maximum synergy.
Thx lancelock for the assuring feedback on DB amps' reliability, & the suggestion on LTA. Will surely look into that direction also. I'm currently driving the Maggies with a Plinius SA reference, & want to experiment with a OTL tube amp but fear their infamous quirkiness.
@nicknick , funny thing, I also own the Plinius SA103 and the ZOTL40 sounds better to my ears. The Berning Amps with its built in redundant protection circuitry is almost fool proof. Sure you still will need tube occasionally but not as often as other tube amps. A set of tubes could last up to 10 years of every day use. There is a lot of info on the ZOTL designs. It’s not your normal OTL circuit in fact many argue vigorously it’s not an OTL at all. It’s certainly not a space heater like my an OTL or my SA103 which I will put up for sale soon.
I took the plunge & bought the Quadrature Zs which arrived yesterday. They sure sound more transparent, airy & vivid than my Plinius. Of course the Maggies need to be repositioned slightly to compensate for the difference in presentation.  Once I get to know the new system better, will probably retain the SA-Ref to drive the Maggie DWM bass panel solely. My wife can't understand why I have so many "boxes" in the hi fi system ^ ^.
@nicknick , congrats on the purchase. I recently went to a friends home for a Saturday of listening and what do you know David Berning came over and brought the Quad Z monos with him. Wow! They sounded good. What sweet power and control. I don’t think they will ever run out of headroom. You made an excellent purchase.
Wow, what an honor to meet the great man himself!!
I knew the Quad Zs were good by reading all the rave reviews, but didn't expect them to be THAT good. They make the pseudo ribbons on my 1.7i sound like real ribbons, & the bass slam is at on par with, if not better than my Plinius SA-Ref. Just wish I had a bigger room to fully appreciate their full potential.