Upgrade to Linear Tube Audio

microZOTL Preamplifier

Level 2 Production Upgrade

“next level of sonic improvements”

The Level One mZ preamp I bought a year ago has been a great addition to my system. I gave it a superlative review. It brought my system ever closer to the “Magic” I am looking for in my music room. As soon as I found out about the upgrade I was on the phone making arrangements to get mine upgraded. The Level One stands on its own for being a world-class preamp. Dead quiet, quick, smooth, sweet (with some tube rolling) describe this fine piece.

Even though I know that audio memory is at its best is subject to all kinds of shortcomings.  I was just totally caught off guard by what I heard right out of the box. As soon as I got home from the trip down to LTA in
Takoma Park, MD, to pick up my upgraded microZOTL preamp, I set it up for a quick listen. The Level one microZOTL was quite a bit more musical than my original preamp (un-obtainable scratch DIY build), but this upgrade unit far surpassed the stock unit.

LTA told me they burn in every piece for a few days to make sure the unit is stable and that the caps are well on their way to forming up. So out of the box, and cold the sound was just superb.

How can a new power supply and output caps make everything ten feet deeper and wider than before? I am not just talking about bass but depth of image, not just behind the speakers but there is no floor either. There is an iron fist grip on the bass that I have never heard before in my house.

I let the system play all night without the power amp on and the next day it just went deeper. The LTA was always quiet but now it is like somewhere between Jupiter and Saturn quiet.

One of my test tracks is La Segunda Sera una Nocha. This is known as a well-recorded and mastered CD. This is the best I have ever heard it.  As I type away I find myself stopping to look over at the Razz, just not believing what I am hearing. It all is just coming together for me, finally. This is the sound I have been seeking for years.

The upgrade are as follows:

  • Power supply cap upgrade: The power supply caps and power storage caps on the audio board are changed to Mundorf Mlytic AG capacitors. The total amount of storage is increased by 22,000uF.
  • Power transformer upgrade: The power transformer is upgraded to a larger custom transformer with multiple windings to improve isolation, which results in lower noise.
  • Coupling cap upgrade: The six coupling caps on the audio board between the tube stages are upgraded to Japanese film caps with gold plated OCC leads.
  • Preamp output cap upgrade: The headphone and the preamp outputs have been separated, and different types of output caps, optimized for each output, are installed. The preamp cap is upgraded to a premium Clarity CMR.
  • Gain Level upgrade: We have added the ability to adjust the gain on the preamp via the menu system. There are two settings: 0db (default) and -10db. This adjusts the volume control to allow for finer low-level attenuation when using sensitive speakers or headphones.

When I first received the LTA microZOTL preamp in 2019 I tried the headphone output on a quick headphone review I did for EveryThingAudio network. It was for a pair of $900 headphones and they sounded very good to me and I gave it a good review. These were hard to drive units and the LTA had just enough guts to drive them. Fast forward to today and I am auditioning a pair of very surprising Headphones that are way south of $500 and through the new headphone output on the upgraded LTA.  The review of these high value and very surprising headphones will be out in a couple weeks. I am completely taken aback at what I am hearing. I know audio memory is not worth too much and these are different headphones but the bass is not muddy which plagues many cans. Not hearing any of that here. the range is full and complete. Very smooth and not tiring at all.  The new output caps are doing their job.  

I just did not think it was possible to improve on the stock mZ preamp, but Mark Schneider and his LTA team added an other level of superiority to this fine preamp.

More magic in the sound room.

The upgrade to Level 2 is $1300 or an additional $1k when you buy new. I feel this is an extremely high value.

Words and photos by Paul Elliott

Video of Mark discussing the upgrade.

Five EARs all around for this upgrade. If you already have the LTA microZOTL preamp it should be a no-brainier to get this upgrade.