microZOTL Preamplifier Upgrade Program

The microZOTL Preamp is a reference-level preamplifier that many consider an “end game” component. The MZ Pre was released in 2018 and has received glowing reviews in publications such as Positive Feedback, Part-time Audiophile, and Home Theater Review.

While all that is true, we are always searching for the next level of sonic improvements, and so we’re happy to announce our Level 2 upgrade program.

Level 2 + Production Upgrades

1. 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.

2. 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.

3. Power transformer upgrade: The power transformer is upgraded to a larger custom transformer with multiple windings to improve isolation, which results in lower noise.

4. 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.

5. Updated volume control w/ gain adjustment and “Hi-Res” setting: The new 8-bit volume control gives you 128dB of total attenuation via 100 individual steps. “Hi-Res” increases this to 199 steps for finer level control. In addition, three gain control options are available: 0dB (default), -15dB, and -30dB. This adjusts the volume level to allow for finer low-level attenuation when using sensitive speakers or headphones.

Balanced Input Transformer Upgrade

The balanced input transformer upgrade adds high-quality Lundahl input transformers to the XLR inputs on your microZOTL Preamp. If you have a source with balanced outputs, this upgrade retains all the sonic fidelity of your source and is a worthy upgrade.

Feedback from satisfied Level 2 Upgrade customers:

“A more robust overall sound and smoother finish - better bass response and glossier highs.”

"Details, staging, smoothness, musicality, airiness were all improved. There was more space between the performers and vocals were less recessed and muddy when the music complexity surrounded the voices. It was easier to pick up the different voices when performers were harmonizing."

“More well-defined details."

~Tim H.

It has been a couple of months after getting back the MicroZOTL Preamp upgraded to Level 2. And wow - what an upgrade! Level 2 takes everything good about the Preamp and makes it better. More bass, a touch more resolution, more air on top, and with that more dimension and liquidity to the music. A preamp is the heart of a system and Level 2 places the unit in rarefied air as one of the highest performing preamps I've heard (and the original was no slouch). In addition, the upgrades to different gain amounts and more steps on volume control are nice additions to functionality. Really, if anyone is hesitating about the upgrade they should just do it - it is almost like getting a new component, although the basic sound signature is unchanged. Kudos to LTA.

~Bill O.

How It Works

1. Place your upgrade order

2. LTA will send you a return shipping label

3. Pack your MZ Pre securely in its original box and packaging (if you don’t have the original packaging, let us know), affix the label, and take it to your closest UPS Store

4. When we receive your preamp, we’ll do the upgrades and ship it back to you ASAP after play-testing and burn-in (see note below).

5. Enjoy!

A note on burn-in:

The upgraded caps take quite a bit of burn-in to offer consistently high quality sound. We recommend 168+ hours prior to critical listening, which is a full week of playing music 24/7.

We prefer to burn in the upgrades here, which we do at no charge, so your preamp arrives to you sounding great. If you would like to get your preamp back without our burn-in service, let us know when you order.

To accelerate the burn-in process, play music through your preamp 24/7 with the volume at any volume level above 0. You can turn your power amplifier off during period you don’t want music playing out loud without affecting the burn-in process.

Return policy: there are no returns or refunds on upgrades. All sales final.