Amp shootout.....Tenor 75wi verses Berning ZH270


in a recent thread there was much discusion of the above 2 amps, whether the Berning was indeed an OTL, and which one might be better.

i have no opinion as to whether the Berning is an OTL. but today a Berning ZH270 owner brought his amp over to compare to my pair of Tenor 75wi's. my system is OTL friendly, with easy to drive speakers, so the Berning's acknowledged advantage in driving difficult loads was neutralized.

these amps have very similar power, the Tenor is 75 watts into 8 ohms, the Berning is 70 watts into 8 ohms. otherwise it is not really a fair comparison....the Tenors are $19900 a pair, the Berning $4500, the Tenors weigh 70 pounds each, the Berning weighs about 10 pounds.....it seems like Goliath verses David. the result is somewhat closer than that.

we played three different discs and each of 3 people listened to their disc in the sweetspot. the Berning owner felt that the Tenor had a more dimentional sound, deeper soundstage but felt the Berning was equal in bass extension and detail retreival. the independent listener felt the Berning was excellent for the money but not in the league of the Tenor in any paramter. my perception was similar to the independent listner; that the Berning, at $4500, is amazing in it's top to bottom excellence, dynamics and musicality.....but....does not do things like the Tenor. the sense of space, detail in the soundstage, texture and microdynamics of the Tenor are at a whole different level.....and they better be for $15000 more.

like the Berning owners, i am a shameless Tenor lover and consider the Tenors better than any other amp i have heard at any price, assuming a reasonably easy load to drive.

the Berning is more like a $8k to $10k amplifier.....and Berning owners should be justifiably proud of their amps.

i did think the Berning had slightly more bass slam than the Tenor, but with much less bass articulation and extension than the Tenor.

we spent the rest of the enjoyable afternoon listening to some great vinyl......an enjoyable time had by all.
mikelavigne
The feedback switch does more than just change the amount of feedback. It also changes the output impedance of the amplifier, which can have dramatic effect on the amp's ability to drive certain loads. In the Normal Feedback mode, it has 1.8ohms output impedance which should give best damping, but in the Low Feedback mode, it has about 8ohms output impedance, which would only be good for higher impedance speakers(16ohms). What kind of speakers were used and what load do they present? The setting used may or may not have been the correct one.
After checking the Kharma website, the Exquisite 1D has a 4ohm to 8ohm load, so the Normal Feedback setting on the Berning ZH270 was the correct setting for them.
Sometimes presentation can be altered to taste or preference, this is a very big factor, so it's really hard to say, I bet, had they experimented with the feedback switch, there also would be several different opinions on which position sounded the best.

This is too much fun, let's all get together at mikelagvine place this summer :)
Allan
Well, I went back and read the manual for the Berning. He says that the low feedback setting raises impedence and reduces speaker damping. To quote from the manual:"Speaker damping relates to the control that the amplifier has over the position of the speaker diaphragm. High damping has the effect of causing the speaker diaphagm to start and stop quickly, and its sonic attributes also show up most dramatically in the bass. High damping is likely to give a tighter, dryer, and more analytical sound and low damping is likely to give a more open and resonant sound."

We left the Berning on normal feedback, which is the low impedence high damping setting. That is probably the source of Mike's comment about the greater bass "slam" of the Berning - it was stopping that big 13" woofer in the Kharma's on a dime. Mike says the Kharma's are a flat 8 ohm load. In the specs, the manual says the output impedence of the amp is 1.8 ohms @ normal, 3.8 ohms @ medium, and 8.7 ohms at low feedback setting. Looks like we should have at least tried the low feedback setting, since that would come closest to matching the Kharma's load, and it would have softened the bass because of the lower damping. Oh well, guess we'll just have to revisit this another day.

By the way, I have never heard the Lamms, but I can say that the combination of the Tenors and the Kharmas and Mike's room treatment produces the best, truest, feel it in your gut bass I have ever experienced outside a live performance (and then only if you are in the real sweet spot in the auditorium). Maybe Mr. Kamm could tell is what other equipment he was using in his comparison.