My MT-32 is (very) noisy, and that's not hiss!

[NickB]

I thought you guys might be interested since I've been having very similar power supply problems.  

I bought a Roland MT-32 off of eBay do play old DOS games.  The power supply the seller gave me appears to be some generic non-Roland adapter (plain grey, doesn't even have any voltage or mA specs on it.  The power adapter worked just fine for awhile.  The MT-32 worked perfectly, no discernible noise.  But then one day the power supply ... well ... MELTED!  

I tried a bunch of  other power adapters from other household devices.  A 9V 85mA adapter wouldn't even power the MT 32 on.  Likewise with other similar adapters.  I then tried a Roland 9.6v 200mA adapter (for a Roland mixer), that powered the MT-32 on but it would make a god-awful noise.  Tried another Roland 9v 300mA adapter (for an effects pedal), similar problems.  

However, a 9v 1000mA adapter (for a Roland JV-35 keyboard) seems to work perfectly.   I had no luck finding a 9v 650mA DC adapter, but replacement 9v 1000mA adapters seem to be more common; I guess I'll try getting a replacement 9v 1000mA adapter :?

[Juho Sippola]

The output amperage digit on adapter only tells how much current it can feed. If that digit is higher than current draw of the sound module, no problem. Adapter output voltage needs to be exactly 9v for proper operation. There are tolerances but the point is to not plug a 12v adapter to 9v sound module or something alike.

My MT-32 and SC-155 are both running on similar Roland 9v 1200mA adapters. They've worked fine except once one of the adapters blew a fuse and I had to change it - just a normal glass cartridge fuse used on electonic equipment. The adapter could be opened with a Phillips screwdriver.

I haven't had any out-of-ordinary noise issues with the equipment at any time, though.