The organ in Capillas was build by Tadeo Ortega in 1776. Its character is typical for the Castillian instruments of the 18th century.
With very low wind pressure it attains a powerful volume. The flue stops are very good, the reeds have quite a different character from those of the Frechilla instrument.
Tadeo Ortega build about 25 organs during his lifetime, all in the Castillian province of Tierra de Campos. He was the last great Castillian organ builder, although he was not famous during is lifetime.
His instruments are without exception of excellent quality. They also are mechanically very well build and the sound leaves a lasting impresssion.
The organ typically has two separate sound boards for the bass registers (Bajos) and treble registers (Tiples), which allow a special playing and registration technique for Spanish and Italian music. The manual is divided
at middle C/ C#.
Pablo Bruna (1611 – 1679) was a Spanish composer and organist notable for his blindness (suffered after a childhood bout of smallpox), which resulted in his being known as "El ciego de Daroca" ("the blind man of Daroca").
It is not known how Bruna received his musical training, but in 1631 he was appointed organist of the collegiate church of St. María in his hometown of Daroca, later rising to choirmaster in 1674. He remained there until his death in 1679.
Thirty-two of Bruna's organ works have survived, mostly in the tiento form. Many, known as tientos de medio registro, are for divided keyboard, a typical feature of Spanish organs.
Here is the link with much information on the instrument on the OAM website:
Registrations in the first comment.