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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
peter_s OP
1,335 posts
 
I'm thinking I should ship it back to David. The shipping wouldn't be costly for such a light amp (insurance could be >> the shipping cost), and he would be most qualified to test the amp thoroughly (including the tubes). Perhaps that would be the best first step. He mentioned on the phone that he listens to all newly built amps for several days, but perhaps this was not apparent.
tubegroover
2,320 posts
 
Peter If you can find someone in your area, maybe a dealer that has a tube tester or possibly a local electronic technician you might want to also look at that option. Infant tube mortality is not an uncommon thing. It usually happens within the first few months. Dr. Berning hand builds these amps himself. I doubt there is anything wrong with the amp itself. As a last resort you can ship it back but I would look into getting the tubes tested locally, if possible. Shipping always involves the risk of damage, maybe I'm too sensitive to it because I've had my share of damages, UPS!!
ken_schwarz
2 posts
 
I loved my ZH270 and still miss it, but I couldn't afford to keep it after I bought a Siegfried...

In addition to the many things you've already mentioned, I found that the ZH270 was sensitive to the type of feet it sat on. My best results were leave out the cones and spikes and use the standard plastic feet on hard, heavy surface.

Cables do matter! The Siegfried is merciless in revealing colorations in the input cables...more so than the ZH270. I get nice neutral sound from Kimber KS-1011. I found that my two "silver" cables had undesirable "zip" in the sound on the Berning amps. Also, I found that monowiring gave a more pleasing sound than biwiring. I use the same biwire cable as before, but I connect the the high and low end cables together again at the speaker end. This gives me a much smoother high end. Your experience will surely vary, but it might be worth a try.

Are you using any power conditioners before the Berning? If so, try without them. I get noticibly better results with the PS Audio Ultimate Outlet.

After buying my Siegfried, I horsed around with substituting NOS tubes of various types. David Berning warned me that it can be a "real adventure" in finding tonal balance...and he was right! I am now back to the original tubes, including the ordinary Sovtek 6SN7s, and all is well. I was able to get best results by choosing different cables and repositioning my speakers.

Do you get the same tonal balance from both speakers? Try right and left alone with a mono signal from your preamp. If they are strikingly different, try swapping right and left speakers to rule out differences in tone to speaker placement. If the problem is in one channel, then you may indeed have a problem with your amp.
rhirsch's avatar
rhirsch
36 posts
 
Hi Peter. I'm the guy Ian mentioned with a setup similar to yours. For me break-in of the the ZH270 was an up and down affair, especially during the first 48hrs. Make sure you let it run continuously the first 2 days. Mine was a little on the lean side in the mid-bass to low-bass region in the beginning. That condition started changing around the 25-30 hour mark. Results may not be the same with 3hrs. here and 4hrs. there to achieve a collective 48. The Berning gear will let you know when the synergy is right in a way I have yet to experience with other mfgs. If a continuous and sufficient break-in period (no cable or equipment swapping during this time) doesn't satisfy I would then send it back to David and/or tube test inputs as suggested. Also, I would leave the Cary cdp running for at least 100hrs. non-stop as suggested in the Cary manual before any serious evaluation. Keep us posted.
allanbhaganinfo
121 posts
 
The chances that there is something wrong with the ZH-270 is extremely low to nil, chances that there might be a problem with a tube is somewhat higher.

I recommend that you leave the ZH-270 on for the next week or so and play as much music as possible through it, it will break-in more.

The tonality of a ZH-270 is as neutral as it gets, any and everything you do will make a difference in what you hear, unshielded cable, metal shelves, stacking, will all hamper/change performance, this is not a short coming of this amp, it's ultimate performance without coloration.

However, ultimate performance without coloration might not be for everyone, wait a week or so, then contact me and let me know where it's at.

Changing tubes is for taste, not to bring up the performance, not everyone is ready nor do they want an amp that reveals everything, there must over 60 ZH-270 owners, all extremely happy, so much so that used ZH-270's have one of the highest resale values in audio, that is if you can find one.

The tube changes can be suited for your taste, while keeping the attributes of the speed and clarity that Berning has designed into these amps, it's not a performance upgrade but a taste that you might be more use to, I hope this explains it better.
Allan
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