Gramophone Dreams #36: Linear Tube Audio Z10e integrated amplifier Manufacturer's Comment

Manufacturer's Comment

Many thanks to the venerable Herb Reichert for his thoughtful column on our Z10e electrostatic headphone amp / integrated amp. We know it takes a lot of time to dive into such a versatile product, and we appreciate the effort Herb put in to so thoroughly explore the Z10e's capabilities.

Herb mentions that the dynamic headphone output fell a bit short of expectations with the hard-to-drive HiFiMan Susvara, and laments, "Why can't Linear Tube Audio give the headphone output the same power and gain it gives the speaker output?"

Since sending Herb this amp for review, we have heard the same from our customers. So, we reworked our original, conservative headphone outputs to be more powerful.

The “HI” output now puts out the same voltage and gain as the speaker outputs, about 3W into 32 Ohms. We are certain that this is ample power for the Susvara and other hard to drive headphones. The “LO” output provides 240mW to 32 Ohms. —Nicholas from LTA

Bogolu Haranath's picture

HR could also review the Linear Tube Audio ZOTL 40 reference amp (with measurements, please), $6,800 :-) ......

nicholas_lta's picture

This is Nicholas from LTA. I am including below the manufacturer's comment we submitted that appears in the back of the print edition of this issue. This clears up the issue of the power of the regular headphone output.


[Note: this Manufacturer's Comment has been added to the main article as a sidebar]

er1c's picture

Your sentence; "if the tones of everything are not accurately reproduced, the audio system is defective and useless" is confusing. I feel some vague kind of loss. Warmest regards anyway. Walks away head down.

MhtLion's picture

For the price of Z10e, I wish it had a balanced headphone out. No matter what anybody says in terms of inherent single-ended design, no advantage of balanced, etc. All that may be true from the product engineer perspective. But, Single-Ended headphone cable is fundamentally wrong. Just who with the right mind will want to spend north of 10k (DAC, AMP, Headphone) and decided to short the return cable path? Would you ever do that with your speakers? Will you short the return cable of your speakers for any reason? Some of these headphones use just as much as electrical current as the efficient speakers. It's just an insanely fundamental design flaw. It does not matter an amp is SE or not, all the headphone out should switch to XLR type, just so it does not short the return path anymore. On average, there is over 20 dB difference in crosstalk alone when you stop shorting the cables. Your 6k amp may be perfectly engineered with SE design, but for the users - it's a very different story.

headinclouds's picture

Like you Herb I really enjoy music through the LTA Z10e. I have owned mine for seven months now and it is a great component. It drives loudspeakers very well and the quality is maintained at high and low frequencies. As you say “I never thought I'd experience bass of that quality in my room—and from a 10Wpc OTL tube amp, no less!”
It is important to distinguish OTL from the circuit invented by David Berning which is ZOTL.
Most conventional attempts to eliminate the output transformer have the tubes driving the load directly. They have problems with low loads and need lots of tubes in parallel to do it.
David Berning’s invention matches the valve amplifier much better to the load with an impedance converter that emulates a near perfect transformer. It gets rid of the problems of the iron cored transformer and its windings. You have noted the audible results. I am struck by how efficient it seems as much of the power put in is converted to sound, and not too much heat.
It is so good that Mark Schneider and the LTA team are bringing this product to us.