The prototype (Nymphe) was one of the earliest of the frigates to be armed with 18-pounder long guns.

The first two - Nymphe and Thétis - carried 34 guns comprising twenty-six 18-pounders on the upper deck and eight 8-pounders on the quarterdeck and forecastle.

The latter two - Cybèle and Concorde - carried an increased armament of 44 guns comprising twenty-eight 18-pounders on the upper deck and twelve 8-pounders plus four 36-pounder obuses on the quarterdeck and forecastle.

Thétis was retro-fitted by 1794 to carry the same increased armament as the last two; she was rebuilt at Rochefort from October 1802 to September 1803.

The design followed on at Brest from an earlier class of three smaller frigates (armed with 12-pounder long guns) - named Nymphe (1777), Andromaque (1778) and Astrée (1780) - built at Brest to a different design by Lamothe's father.