A branch of the Ramakrishna Math. Their publications are meticulously proofread by Sanskrit and Tamil scholars. Their Sandhyavandanam booklet includes precise svaras for the Yajurveda.
However, a will preserve the original grantha or Tamil script while maintaining the Vedic swaras (denoted by symbols like a small circle or line above the letter). yajurveda sandhyavandanam pdf tamil extra quality
For those seeking comprehensive and "extra quality" guides that include both the procedure and the deeper meanings in Tamil, the following are reputable sources: Sandhyavandanam procedure - Sri Vaishnava cyber satsangh A branch of the Ramakrishna Math