Hello, Everyone.

I am a total beginner. I have been playing in Standard E tuning with either 0.09's or 0.10's string gauges for a while and wanted to try something new. I have an Ibanez RGT42DXFX that I purchased used.

I took it to a guitar tech recently just to get it set up as it was used. I had them setup and tune to D (Full Step Down). They did so with the 0.10 gauge strings that I provided. When I received the guitar back I noticed that my Low D string was buzzing on Open, 1st & 2nd Fret.

When I tuned this string up to Standard E, the buzz when away. I tried putting on 0.11-0.49 string gauges to help with this buzz. I also raised the action on the Low strings. However I still have buzz. The buzz is slightly less now with the thicker gauge, but I would prefer if it was even less that than and I don't want to keep raising my action to do this as I feel it is already too high for my taste. The Truss Rod is in good shape and I have a very slight bend of relief in the neck. I don't see any strings touching frets when measured.

Just wanted to see if anyone has any advise in this matter and if you have found a way around this. I would like to stay in D and even try out Drop C at some point.

Please let me know if there is anyway that I can trouble shoot this issue or if this is just inherent with the tuning. Any feedback or advise if appreciated.

Tuning is irrelevant. You probably have a nut slot cut a bit low or a slightly high fret.

The fix is to fix the nut slot (shim the nut, replace the nut) or find the slightly high fret and make it level with everything else.

Take it back to the setup tech and explain the issue. Where are you located?