09258: All Megatech games: Megatech Games have a Loud Noise in One of the Sound Outputs

ID	Category [?]	Severity [?]	Reproducibility	Date Submitted	Last Update
09258	Sound	Major	Always	Sep 11, 2025, 11:17	Sep 11, 2025, 12:03

Tester	con5duros	View Status	Public	Platform	MAME (Official Binary)
Assigned To	hap	Resolution	Fixed	OS	Windows 11/10 (64-bit)
Status [?]	Resolved			Driver	sega/megatech.cpp
Version	0.280	Fixed in Version	0.281	Build	64-bit
		Fixed in Git Commit	adc8879	Github Pull Request #

Summary	09258: All Megatech games: Megatech Games have a Loud Noise in One of the Sound Outputs
Description	There's a Background loud noise in every Megatech System games. It seems that the sound System for those Games is Broken. This Bug is only in Mame280, in Mame279 the Bug is not there. It Seems that the problem is in the DSP output, in the Volume Levels, minimizing the DSP Volume the problem tends to mitigate.
Steps To Reproduce	Just run one of the Megatech Driver Games, tested in all Megadrive based games of megatech system
Additional Information
Github Commit

Flags
Regression Version	0.280
Affected Sets / Systems	All Megatech games

Attached Files

No.23675 hap Developer Sep 11, 2025, 12:01 edited on: Sep 11, 2025, 12:02	Yeah, it's a new regression and it was already fixed. Some other Sega hw games had the same bug (no need to write more MT bugreports), for example: mame megadriv truxton