Problems getting the best out of my Berning


Hello fellow Agoners,

I beckon for help from experienced users of the Berning ZH270! I just received mine new a week ago, and although it is an incredible amp, it is not meeting my expectations. HELP!

First the good news:

This is the fastest amp I have ever head, and it has virtually no noise floor. I am truly impressed with these aspects. It handles most everything with ease and clarity.

Now my system:

Proac 2.5 loudspeakers
Cary CD308 and Arcam FMJ CD23
Kimber PBJ Interconnnects
Audioquest Type 4 cables

(I've also used Dynaudio Audience 72's and all MIT cables, and Triangle Titus + Audioquest Slate cables and PBJ IC's).

OK - now to the problem:

On all three setups mentioned above, the amp seems strongly biased towards the midrange and upper midrange, resulting in a fatiguing presention. There is a significant decrease in bass (not detail, but the actual movement of air) from the other amps I have used for comparison (Classe CAP 101, Pass Aleph 3, Adcom GFA 5400). While the detail and fastness are truly amazing, the midrange emphasis is getting the worst of me!

I've spoken with David Berning and Frank S (FS Audio.com) and both encourage some tweaking to get rid of this perceived (psycho?) acoustic bias. Frank is going to send me some interconnects to try. David mentioned that others have changed the tubes. He doubts anything is wrong with the amp.

Is this all in my head, or have others had similar problems and needed to make adjustments to get it right? While all my other amps are currently SS, I have trouble believing that this is the "tube sound" (I've heard other tube amps). Other threads mention system tweaking to get rid of a "glare" with the ZH270, changing tubes, sensitivity to cabling. My perception of the sound is pretty strong - currently I like my Aleph 3 a whole lot more with the existing setup.

I'm willing to put some time and money into making this work - because in all other respects, this is an absolutely amazing amp. Perhaps it doesn't suit my ear - but I want the advantages of this amp without the disadvantages I just mentioned. Please - suggestions on what to do from all you experienced Berning fans... so many high commendations cannot be that far off (right?).
peter_s
Ken, I am doing just that. I have a pair of Lowther EX3's in modified Voigt Pipes(100db), and I have a special order cutom amp coming from David Berning. It will be a battery powered, choke-loaded, SET ZOTL, with type 45 output tubes, and 2 watts nominal. I will be using the Emission Labs VV45 Mesh-Plate tubes. It will be loosely patterned after the Siegfried, but with the obvious differences of battery power, and choke-loading, and of course the type 45 tubes. Some people I've talked to are calling it the "Holy Grail" of amp designs. Probably pretty close.
Ken I find many of your comments interesting. So far as sibilance is concerned I have often found this to be the result of interaction of components and wire and have experienced my share of it. I have never heard this emphasis through the zh270 or the previous Transcendent OTL amp I used. The system is wired with copper interconnects and Millersound speaker cable which is aluminum with covered with a copper flex wrap. I have been using the Millersound in my set-up since I had the Transcendent and it works extremely well to the point that I have stopped looking for "better" speaker wire after going through numerous ones.

The interconnects (Luminous Technology Synchestra Signature) were a notable improvement over the Harmonic Technology Truthlink. The Berning allowed me to hear that Truthlinks are intrinsically smooth sounding cables but somehow there is a sameness to all music, much of the subtle nuance of the performance is missing in action. As it happened a friend bought a pair of Luminous cables and his system transformed, I don't use the word lightly. There was that organic wholeness and a separation of instrument lines ala live music that you speak of that were revealed when one cable from the pre to the amp was installed. It was the most significant improvement I have heard his system make and this includes even swapping the Berning in. To put this in some perspective, he has tried numerous cables including MIT, Exos, Harmonic Tech Pro-Silways and Truthlinks, Tara labs, etc. each resulting in differences and some improvements in one area at the expense of another. The Luminous was a revelation and trying to analyze what happened took a back seat to listening to the music prior to which I had a difficult time doing with this system because I always was drawn to the artifacts of the reproduction, in a word, fatiguing.

I don't want to get into a cable review because my point is to emphasis not only do cables make a difference as you note above, they can make a DRAMATIC difference in bringing out not only the musicality of a system but the artistry of the performance. After hearing this in his system I did some research on the cable to see if there is a reason why it should make such a difference. Pretty straight forward, 6 nines continuous cast, (the truthlink are also continuous cast) with a special termination that may come into play. He brought the cable to my place the next weekend and while it didn’t transform my system like it did his, it was certainly a big improvement in the areas that I felt the truthlinks to be weak. Nuance or realness conveyed much better, which I attribute to greater resolution of harmonic detail, tighter and better control of bass, and probably the most notable, to me an incandescent, airy natural portrayal of the upper frequencies.

My litmus test of how my system is performing is massed vocal recordings, Ode to Joy Beethoven's Ninth John Elliott Gardner on Archiv is a good example. Nothing is more difficult to reproduce and very seldom do I get goose bumps listening to a choir on a stereo system. It is generally so far off the mark of the real thing. The speed I speak of with OTL’s and the zh270 is the ability of the system to reproduce instruments and vocals without overhang or adding a richness and to keep everything together yet to reveal the air, space, image focus and separation of the performers as we might hear it in a live performance. I would think if an amp is too fast, if this is possible, it would have the same effect as a tt platter going too fast, there would be a chance in the pitch of the instruments and voices. What could be perceived as artificial is if the dynamic shadings of the music aren’t keeping up with the above, this could certainly lend a perception of something being amiss. At this level of performance in an audio system, each element of the chain has to complement the others or whatever area has a shortcoming will draw attention to the whole.

Your insight was most welcome. I am currently going direct from the digital source to the amp. Prior to installing the Luminous cables, I was going from my CAT SL-1 pre to the amp and preferred it somewhat better with the truthlinks. There really wasn’t an earth shattering difference. With the Luminous cables there is a big difference and I much prefer direct. The presence on a great performance is palpable. Performances can swell you with emotion. It is a level I’ve never experienced before and it is consistent with music I love and the effect I get when attending a great live performance. I now realize that the pre-amp has to go and have just ordered a new one recently. I wasn’t particularly happy with the phono stage and the line stage is now just ok. I sure hope this new pre can keep up with what I am currently hearing. If I’m real lucky maybe it will be an improvement. What I’m really looking forward to is the phono stage. The bottom line with the zh270 is that I have finally found an amplifier that can showcase the potential of my system. Of course it doesn’t hurt that my speakers are a nominal 8 ohms with no dips that could alter the tonal balance. I generally prefer the normal setting with great recordings. I listen equally as much through the medium setting going back and forth often trying to decide. I only listen to the low feedback setting on overly dry recordings. As Peter notes, it is a bit too ethereal, not real but still pleasing. It’s nice having the flexibility. I sure would love to hear the Siegfried on Siegfried (Wagner’s)

Tubegroover and those interested.
Yes, I hear the improvements that the tubes make, yes, it's certainly a big hell of an improvement to me and most of those that hear it an have them, it's shocking how good but not everyone prefer it, believe it or not, some may want that glare, it's not a tube glare, it's a true glare, it's there in live amplified music, it's there in digital recordings.

One person preferred the stock tubes in all, a very small amount but still shows that improvements are a taste thing, there is no other explanation for it.

So to call it an upgrade, it would have to be better for everyone.
One thing in Audio I have learnt is, for every one thing a person upgrades to, another upgrades to the opposite, if you have speaker cable A, an you hear speaker cable B an love it, there is always someone that had speaker cable B and now loves speaker cable A, so the only logical explanation for this is personal taste but then I suppose there is no logic in audio :)
October 10th Update!

Hello to all you helpful Berning owners! Well, it's been a couple of weeks and here is what I have to report.

1) I took the unit to an electronics expert person who just happens to live in Flagstaff (used to work at UC Santa Barbara), and he took it through some bench testing. The results were interesting, much of which above me. But the tubes were working fine.

2) I have kept the amp on for over 100 hours, and the break-in has improved the bass response to that of (or near that of) my other amps: Pass Aleph 3 and ARC VT100-mk2. Still dominant in the midrange though, and a bit fatiguing.

3) Alan B (see posts above) lent me a quad of Cryo'd Sylvania output tubes, and I popped them in and listened today. There was a significant improvement. The bass got more detailed and stronger. Overall detail increased, openess increased, and soundstage improved. Despite a ground problem with my Rogue 66 preamp, the noise floor still seemed way, way down there! Listening to Nora Jone's "Come Away With Me", the cymbal brushes lost a bit of excess metalic nature and became more "brushy". There was a reduction of the midrange emphasis, but it is still a bit there to my perception. Now at the point where I could see adjusting to it, as a different sound approach.

4) I'm away for four days vacation, but when I get back, I will be doing more listening comparisons between the amps. A quick impression now: while the Pass sounds flatter than the Berning, the Berning sounds clearer (e.g. clearer vocals and kick drum). Anyhow, I'll also be working with system synergy. Newly arriving are a pair of Cardas Neutral reference biwire speaker cables, two Neutral Reference interconnects, a Golden Cross interconnect, and some Harmonic Tech interconnects. All are on loan in order to work with the synergy. I will keep y'all informed.

5) I'm really wondering whether I should be trying different input tubes, while I'm trying to make this decision. Any advise? Where to get them...

Thanks All. Peter
Peter, your perceptions of the effects of the cryo'd tubes match mine perfectly. I also have cryo'd NOS input tubes. I'm posting from work, so off the top of my head I can't remember the exact designation of them--G.E. 5 star platinum and Brimar Black Plates? I'm sure that the other berning owners will correct me. Anyhow, I got them from Tubeworld. If you contact him, the guy at Tubeworld (Brendan?) knows exactly what you want because apparently all Berning owners go for the exact same set of tubes. They were a little pricey, but as far as I know that is the only source. In my opinion, and I'm not sure that this opinion is shared by the other Berning owners, the cryo'd 6Jn6's made more of an impact. However, I have to say that at the time I was changing other system components too--interconnect, CD player--so I don't have a very good baseline to compare them to.