Tesla NZC 431, Tesla ARS 1034

I would say the sound is smoother and more cohesive after the modifications—everything sounds more refined.

The noise artifacts I used to notice during very complex musical passages have also disappeared.

They play quite loudly without issues; the sound doesn’t become muddy, and the mids and highs aren’t aggressive like they were before the modification.

The sound is well-balanced, clear, and clean.

Low-volume listening is pleasant and relaxed.

All the modifications had a positive effect, making this a beneficial long-term solution for me—personally, a better choice than buying a new unit.

I was also extremely satisfied with the entire process and your approach, and I would certainly recommend your services to others.

P.S. The original ARV 3604 tweeter was replaced with a Monacor DT-300.

The ARZ 4604 midrange driver was modified, as was the ARN 6604 woofer.

Frequency response measured in a standard room at a distance of approx. 1.2m, on-axis between the midrange and tweeter.

Blue represents the original response; yellow-green shows the response after modification (new crossover plus DT-300).

From the NZC 431 unit, the turntable mechanism and modified phono preamp were retained, while the power output stages and the entire power supply were replaced.

The original cartridge was damaged and has been replaced with an Audio-Technica AT-91.