Hello guys!
Three questions :
a) Is working the testing net of digibyte? ... Because the wallet (in testing mode) don't receive blocks and no connect to the network .
b) Is the Digibyte's Groestl implementation the same to MyriadCoin Groestl?
c) Is using a specific groestl implementation?
Thanks in advance!

Yes, DGB groestl implementation is the same as Myriadcoin Groestl.
I just tried to run wallet in testnet too and "no block source available". Curious, why do you want to run testnet?