Steve Guttenberg reviews the new Berning EL84 OTL integrated amplifier

[Xulonn]

The 10wpc, $4,900 Linear Tube Audio Z10...

Why buy a 100wpc Benchmark amp when you can buy this 10wpc gem for nearly twice the price

The Berning's tech is one of the reasons the Z10 sounds more transparent than any comparably priced tube amp in my experience. The design uses two 12AT7s, four 12AU7s and four EL-84 tubes. Where most tube-based power amplifiers use special transformers to couple the power tubes to the speaker outputs, the Z10 does not. Instead, the design features a zero hysteresis transformer-less technology patented by Berning. The result is an amp that runs much cooler than most tube designs, which leads to longer-than-average tube life expectancy.

I was really excited to read in an Audiogon review that this tube amp matches solid state amps with respect to "image specificity" /snark

At LTA's website, specs indicate -94dB SNR, but nary a mention of distortion figures!

I'm being a bit snarky here, but until proven otherwise, I have a feeling that this amp may not be a great performer - unless you like tube euphony without the tube glow - which is part of the tube ambiance that I like for nostalgic reasons.

Edited to finish the entry - I apparently hit the wrong key and it jumped out and published itself before it was completed...

 

[Xulonn]

Perhaps Amir or a friend could get one via the 14-day free trial and test it. I am curious about how it would test, because Daivd Berning is a well-known audio designer with unconventional ideas and designs.

Although subjective reviews seem to like Berning's OTL designs, my quick search didnt find a review with thorough testing and measurements. The only testing of a Berning amp I found was this one from Stereophile in 1995 of the EA2101, a 100wpc power amp with a switching power supply and output transformers - not OTL. It seems that distortion was quite high and affected the sound.

 

[Blumlein 88]

https://static1.squarespace.com/sta...9cd39ca4ac18/1431112423789/Berning+Patent.pdf

They are a variation on tube based switching amps with DC to DC converter coupling in place of transformers. A neat design. I too would like to see one tested. They switch at 250 khz or at least the earlier ones did. 2nd order filter on the output at 100 khz I think it was.

 

[Frank Dernie]

https://www.sarte-audio.com/sites/default/files/folletos/folleto_devialet_1.pdf

I always thought that Devialet did a much better job of using a switching amp to provide the current and a class A solid state amp to define the voltage than Berning. The only person I know who had a Berning amp changed it for a Devialet about 5 years ago.

 

[Panelhead]

Berning knows what he is doing. I had a EA-230 a long time ago. May have been a little hard sounding, but was very quiet and had solid bass.
A friend with Quads and Demian Martin subs said the Berning and horns gave him a headache. His system seemed rolled off to me.
Not so sure on this tube switching amp. Seems like worst of both worlds.
Would like to see an AP test on it.

 

[SIY]

I reviewed the Linear Tube Audio Ultralinear a few months back. The concept is fascinating and creative. The measurements were a very mixed bag.

The manufacturer felt that I missed the point and that the amp is not designed to make a small signal bigger and do nothing else.

 

[jsrtheta]

I reviewed the Linear Tube Audio Ultralinear a few months back. The concept is fascinating and creative. The measurements were a very mixed bag.

The manufacturer felt that I missed the point and that the amp is not designed to make a small signal bigger and do nothing else.

Fool. An amplifier is supposed to materialize the inner essence and torment of its designer.

Do you have no feelings?

 

[BillG]

I'm being a bit snarky here, but until proven otherwise, I have a feeling that this amp may not be a great performer

Guttenberg is a former high-end audio salesman, and this shows in his reviews. As they say, caveat emptor...

 

[Blumlein 88]

Fool. An amplifier is supposed to materialize the inner essence and torment of its designer.

Do you have no feelings?

I think you are on to something here. The amp SIY reviewed had a transformer. David Berning was in agonized torment that tubes need transformers. So he came up with a tube amp that didn't need transformers. And not that old OTL type Futterman design which is so wimpy.

Of course Acoustat took a different approach. Had a speaker which needed 5000 volts so came up with a 5000 volt tube amplifier with no need of transformers. Somehow their torment didn't make it into the design however. Jim Strickland just wasn't all that tormented I don't think.

 

[Blumlein 88]

Guttenberg is a former high-end audio salesman, and this shows in his reviews. As they say, caveat emptor...

You sure about that former part?

 

[BillG]

You sure about that former part?

Well considering how that segment of the industry appears to operate, no...

 

[SIY]

I think you are on to something here. The amp SIY reviewed had a transformer.

FWIW, it used the ZOTL technology. Like I said, very clever and innovative. I kept thinking that with just a few changes, the circuit could likely perform very well, but as it is, there's problems.