Music stores in Budapest

Are you in Budapest now or are you planning to go to Budapest?
We stayed one block from the opera house in Budapest and there are stores all up and down Andrassay.
I find the following sentences online - not sure if it would help you.
"If you want to check out some guitar stores in Budapest there are some on Andrassy boulevard, in the Opera House area."
"You could check graigslist in Budapest and see what is out there for private party sales.
The 7th and 8th districts in Budapest have many music stores, there is one at Dohany utca and Korut utca in the 7th district east of the New York coffee house.
I do know a small guitar store now that I think of it, it is on Alsoerdosor Utca just off of Rakoczy Ut between Korut and Keleti train staion(in the 7th district). I think they speak English in there."

Thanks for all your help.
I will be in Budapest next month.

Three thoughts:

Rozsavolgyi Bookshop, at Szervita ter in the very center of the city. Upstairs. They have a limited range of guitars (my son scoffed at them all, given their prices).

On Nagymezo utca, if you are coming towards Andrassy from Kiraly, there is a big yellow church at the corner of Kiraly and Nagymezo. As you walk towards Andrassy, on your right, the next building after the church, in the tiny side street between the church and the building there's a door with entry to a large music shop in the basement. They have 3 or 4 classical guitars.

Finally, I have not been but am told it is the best option, Coda, at Rakoczi ter (ter, not ut). If you are facing the square and the construction in it, on the left corner on the same side of the korut as the square, there's a large, excellent musical instrument shop...