Berning ZH-270 Replacement


I would value suggestions from anyone who has listened to the David Berning ZH-270 complete with the upgrades and who can advise on what integrateds if any they have heard that better it.

I am running Sonus Faber Guarneri Homage speakers with a subwoofer.

Advice and recommendations welcome

Just had it for 1 day in the stock form running with Merlin VSM-MM's in early 2005.The best amp to go with these.Slightly better than an Ayre V5,a little better than a modded Counterpoint NPS220 and alot better than some others.Not much info,but it all adds up,good luck,Bob
Barry, No integrated I have heard competes with an upgraded ZH270. My suggestion would be to wait for a ZH270 to show up on the used market and grab it, as the 270 should mate perfectly with the Sonus Faber Guarnari Homage. Even a stock ZH270 with NOS tubes will be hard for most any integrated to compete it. The OTL sound is special and the advanced capabilities of a ZH270 are unique to Berning designs.
I must digress, and I think I'll get alot of flack for this, but wrt to the ZH-270, I don't see what all the hubbub is (bub). I had one about 7 years ago, with the NOS tubes, and I felt that it sounded way too forward and aggressive. I heard it on multiple systems, four to be exact, and the sonic character was the same for all. I returned it to David Berning to make sure it was OK, and he said there was nothing wrong with it. I just don't get it. Several friends all had the same impression of the sound. Anyone here on Agon perceive it the same way?

In any case, since Sonus Faber speakers are on the warm side, it may match with them well.
Hi Chris

Just to clarify I already own an upgraded Berning ZH-270. I just wanted to see if there were any other better options to now consider.

Hi Barry, Better options? Not likely at anywhere near the price point but different options, yes of course. If you want to check out something different for the fun of it you could try a one of the switching (digital) amps or maybe a Chip amp or pure Class A SS? What you won't find find is the sound an OTL amp gives you, in that sense you have been spoiled already....much less having a ZH270 and not having to deal with all the limitations of conventional OTL amps!

Peter_s, there are too many variables to consider before determining why the ZH270 you previously owned did not perform satisfactory in your system. Cables, Feedback settings, room, associated equipment, ect..... You get the point :) Sometimes, its just difficult for hobbyists to adjust when they first hear a Berning ZH. Typically this is because they have lived for so long with conventional tube and/or solid state amplifiers both possessing various colorations they are taken back by the clarity and revealing nature of a Berning ZOTL amp. But, for those interested in hearing the soul, emotion and drive of the instruments and musicians contained within the recording, I can think of no better product to tell the story.

In the end though, it boils down to what sounds best to you in your system and suites your own personal tastes.

The Berning is not a true OTL amp.

Ralph Karsten provided an in depth explanation in a thread here a year or so ago. Search the archives for it.

That being said, the ZH-270 is a terrific product.
I had a ZH-270 that was mated to Chris Sommovigo's Stereolab Angelus speakers and it sounded terrific. I moved it and other componenets in my system to help come up with the down payment on a condo. Then the bottom fell out of the market and not long after I was out of work. I was able to get back on my feet quickly and found a Luxman L590 A II at almost half price.

In short, I don't miss the Berning and it makes a great combo with the Angelus speakers.
AudioFeil International, Correction, "A True OTL" is precisely what a Berning ZH270 IS - OUTPUT TRANSFORMERLESS. A Futterman OTL based or derivative is what a Berning ZH IS NOT. There is a specific distinction to the cutting edge, modern OTL design topology executed within the Berning and the 50+ year old highly limited and unstable OTL technology used in the Atmasphere.
I joined the Homage club a short while back. Usually you try to find the best amp to make your speaker sound its best. The GH's are unique to me in that they seem to make each amp sound its best. When they were delivered to my house I hooked them up to a vintage Marantz 19 receiver just to see if they survived shipping. They sounded great. Hooked them up to my Carissa Sig (845 SET), great. Seemed to have a special synergy with my 300b. They now reside in my home/office with a Pass XA30.5 driving them to my pleasure. Now that Summer is here I will using my Red Wine Audio 30.2 to help with the heat issue. I'm pretty confident that will be good too.

Recommendations? Pass has a 150.5 integrated that I have a feeling would work very well with the GH. I can let you know how the RWA works if you care. It's an integrated. Good luck.
IME, the Berning is a great amp, but not great as an integrated. The volume control is nothing but average. Try it with a good separate line stage, and only then judge the quality of the amp.
If you are limited strictly to integrateds, consider the VAC. If you have power-hungry 4ohm load, then I'd look at Pass. Cheers,

06-24-09: Peter_s
I must digress, and I think I'll get alot of flack for this, but wrt to the ZH-270, I don't see what all the hubbub is (bub). I had one about 7 years ago, with the NOS tubes, and I felt that it sounded way too forward and aggressive. I heard it on multiple systems, four to be exact, and the sonic character was the same for all. I returned it to David Berning to make sure it was OK, and he said there was nothing wrong with it. I just don't get it. Several friends all had the same impression of the sound. Anyone here on Agon perceive it the same way?
I certainly do! I had posted similar comments re. the ZH270 in this thread way back in 2006:
I also did not hear anything special from this amp & I heard it 1 person's system & then invited the gentleman over with the ZH270 to listen to it in my own system. No cigar in both cases, I'm afraid.
In the above thread, you'll read that many others changed their minds over time to agree with my position but you got to go out & listen with an open mind. Once these other people did, they realized that the ZH270 was average, at best.
Now, Berning's new Quattro (I think I got the name correct) that I heard at RMAF2007 is/was an excellent product. Much more expensive but, my gosh, what great sound. superb!

Of course, these are my personal opinions. YMMV.
Chris74, I humbly suggest that you have no idea what you are talking about. The output transformer in the Berning is clearly visible in the patent schematic! -even if you take the tack that an air core transformer is not in fact a transformer (which of course it is), ignoring the role that the semiconductors play in the output section still puts it outside the category defined by the acronym 'OTL'.

It is true that in the early 70s and late 60s, Allied Radio Shack referred to some of their amps as 'OTL', but generally the term refers to a tube amplifier, not semiconductor, and also not an amplifier that uses both a transformer and semiconductors for impedance transformation in its output section.

Of course, cats are distantly related to dogs, so I guess all dogs are really cats, right :)

BTW, the Atma-Sphere approach to OTLs was patented in 1986, and is not a Futterman circuit or a derivative thereof. Contrary to your assertion, it is *unconditionally* stable, as the amp cannot be made to oscillate under any load condition, regardless of input signal condition. It was the development of a fully symmetrical circuit that is inherently low in distortion that allows for this, so feedback (a destabilizing feature in any amplifier design) was no longer required, unlike the prior art.
Bombaywalla - it's somehow comforting to know that I'm not the lone dissenter to this love fest! I really wanted to like the ZH-270 - I thought it would be the answer to all my needs. I don't think that it was the source components or the cables, as I listened to it on 4 systems - though I imagine there are better synergy combinations than what I experienced.
With the exception of a small input DC blocking cap, the ZH-270 is DC coupled, so how is this possible with a output transformer ?? I tell you how, it's not !!
We've gone down this road time and time again, it's obvious it's beyond comprehension for most, but an OTL it is.

A person has the tendency to believe what they can understand and doubt what they don't and since this is a highly technical piece beyond anything ever made in audio, it leaves a lot of open endness for somewhat misguided debate.

And as always listen and compare for yourself, not everything is for everyone.
I second Sbank's response. The ZH 270 benefits from a good preamp. I use a ZH 270 in a second (Summer) system with a FS pre and the sound is terrific. I use Joule amp (vzn 100) and Joule pre in the Winter when heat is not a factor. The Berning/FS combination comes close IMHO. I do not think you will find the ZH 270's performance in SS gear - mine replaced a Rowland Concentra II integrated and as much as I liked the Rowland the Berning was so much more involving. The Berning can also benefit from some tube rolling. I recently inserted some Telefunkens and the mids and highs improved - more open and extended.

Many thanks for all those who have responded so far, some very valuable feedback for which I am grateful.

I would however appreciate if this thread does not continue to get off track into a debate about if the Berning is or is not an OTL design, that is not the question I asked or even remotely wish to have debated.

I would like to get back on track and hear of peoples experiences with the Berning and other integrateds they may have heard/tried and consider recommendations opinions on sonic abilities etc of them all.

You're correct Bpinder.

One need only search the archives to find Ralph's detailed and comprehensive explanation concerning the Berning and why it is not a true OTL.

Or email him directly.
Bpinder, just a FWIW, This topic comes up again and again, and every time I wind up with a bunch of messages about the thread in my email box. I try not to respond unless there is just plain and simply misleading or outright false 'information'. That will cause a response, simply to set things straight.

In this case, my company was mentioned specifically in conjunction with false statements about our products.
Ralph, A basic principal of Futterman tube amps is they use banks of tubes in a series, agreed? Atmasphere amps do likewise yet you claim the Atmasphere are not derived from Futterman. Tweaked and much improved, yes and kudos to you for that!

Not fully understanding the highly advanced Berning design is something that you cannot be blamed for. However, to call it a non OTL design is absolutely mistaken and incorrect. The ZH is DC coupled for crying out loud! The DC to DC converters are NOT transformers, their role is for matching impedance in accordance to load. But you should know this already, as this has been explained on the threads and elsewhere time and time again.
Barry, how much power do you need to drive the Sonus? What is the impedance of the speaker like?
Hi Chris, if it were as simple as that!

The Futterman is a 'totem-pole' circuit and is asymmetrical. Our amps use a modified Circlotron which is half the output impedance and *is* symmetrical. Futterman amplifiers usually have output coupling caps and large amounts of feedback, our amps employ neither. Pretty big differences- they amount to reliability and performance, part of why I've been able to be at this for over 31 years, longer than Futterman at this point.

You can look all this stuff up on the web; mistaking our amps for Futtermans has been one of our biggest marketing problems. This is what I meant when I commented that you did not know what you were talking about- it was not meant in a mean way, just simply that that it is the case.

We have a direct-coupled output and so does the Berning, but the Berning uses a DC to DC converter *and* an air-core output transformer for the power tube(s). Neither the latter nor former will be found in an OTL, in which impedance conversion is done by the tubes and the tubes alone.

I have been very careful to underline my admiration of the ingenuity of Berning's concept in the past and that has not changed. I think its brilliant! -but an OTL it simply is not.
Guys please get off your OTL soapboxes and stop hijacking threads in order to display your supposed technical expertise and have a bit of respect for others if its not too much to ask.

Now back to the thread and thanks to all those who have assisted so far.

Keep your non OTL opinions and experiences coming please


Hi Pubul57

The Berning has enough power at normal to resonable listening levels but if one starts to push it to anything more it starts to strain slightly.

As far as impedence of the Guarneris go I am not really sure to be honest as there are very conflicting specs.

bpinder, why don't you contact Sonus Faber and see what they say, I don't know how much input Franco has anymore but he still owns a ZH-270 and the first introduction of the Stradivarius was done using the modest ZH-270, I think it was Fremer what visited Franco, look up the stereophile review.

It surprises me that the ZH-270 is strained at higher levels, have you played with the volume control.
There are several reasons why I am surprised but one mostly is that the ZH-270 does not act like most amps when pushed, because of the sophisticated auto bias, it senses when it's close to clipping and reduces power to the amp, this happens at a super fast rate up to thousands of times a second, so all that might be perceived is a slight reduction in dynamics.

One way to tell if you're reached close to output power is keep turning the amp up, it should react with very little difference in perceived volume, if there is a volume increase then it's elsewhere in your system.

These amps are used by so many manufacturers for designing it will surprise you, including the speakers mentioned here by jwmazar Chris Sommovigo's Stereolabs, what makes these amps great for this, is what makes it unforgiving for the average audiophile, they are not filters which is a limit of the typical design constraints, get it all right or this amp is going to tell the story.
Hi Allan

Thanks for the helpful response. Yes I was aware that Sonus Faber used the ZH-270 and that was actually the main reason I went for it and I really have no problems with it from either a sonic performance or reliablility point of view, in fact it really does have a very nice synergy with the Guarneris.

The reason for my post was I guess it is a case of is the grass greener on the other side and with the passing of time I was testing opinions on other possible newer options.

Also with the Berning not having a pre out connection I suspect I am not getting optimum performance from my powered subwoofer having to drive it piggy backed on the normal speaker outlet terminals. This is the option least prefered by the subwoofer manufacturer, they recommend the pre out connection to RCA in on the Sub but maybee I will just have to live with that compromise.

Do you know why Franco chose the ZH-270 ?

Ever thought of just breaking down and going with an active pre!
the other option is we can talk you through a resistor/divider network design, that would drop the gain say 20-30db and sum both channels, then you can run that to the low level of the sub input.
Any chance of bringing back the ZH-270?
pubul57, there were many factors that contributed to David's decision to stop making the ZH-270, which was in high demand and close to 3 years out of production still is, he gets about 2 inquires a day asking for a "last special ZH-270", just one more.

The problems are that there is components that has to be specially made for the ZH, some can only be made by a single specific manufacturer in Europe and then some can only be made by David, these component are only for the ZH and serve no other purpose in anything else in the world, tooling, minimum quantity, inflation cost, parts increases, so if you take into account that a ZH-270 has over a thousand parts, all this adds up quickly.

Dave had bought, what he thought was a lifetime supply of these parts for the ZH-270 but after a production run of 11 years, they ran out, in pricing out a new run of ZH-270's the cost would have made them close to $11K, also the chassis was homely and that needed updating, so his logical step was the Quadrature Z, a no holds barred statement.

Take heart though, there is trickle down technology from the Quadrature Z coming into a new 30 watt Stereo amp, called the ZH-230, new chassis, higher bias (closer to Class A), special new low loss material board, new impedance converter device with a fixed frequency of 500kH vs. 250kH for the Zh-270, lower distortion, higher bandwidth and some other unique abilities, price will be more than what the ZH-270 was but less than what a ZH-270 would have to be.

ZH-2100 100 watt per channel Stereo amp to follow next year.

As always, limited availably.