Wattage requirement for the Tascam 388? Looking for a step down transformer.

[38869420]

Hi,

I've got a 60hz hum going with my tascam 388 and think it's the crummy step down transformer i'm using (USA machine 120v to Australian 240v).

We've got a place in Australia that makes great transformers, but just trying to figure out my wattage requirement before ordering. The manual shows the volts, but not watts from my looking.

Thanks

 

[rob aylestone]

I googled 388 spec and first result says 120w? Why do you assume it's the transformer? They usually either work or don’t work. Mains voltage transformers have no hum reduction or creation properties? Hums come from ac current leaking? Grounds are 99% guilty in practice.

 

[Chilljam]

Hi,

I've got a 60hz hum going with my tascam 388 and think it's the crummy step down transformer i'm using (USA machine 120v to Australian 240v).

We've got a place in Australia that makes great transformers, but just trying to figure out my wattage requirement before ordering. The manual shows the volts, but not watts from my looking.

Thanks

I had the same problem (60Hz hum) with a Tascam MSR16 using a cheap eBay step down transfer 240v - 120v.

For me, the key was to get an isolated transformer. I got exactly this one from Jaycar https://www.jaycar.com.au/250w-240-120v-isolated-stepdown-transformer/p/MF1082

Pin drop silence as soon as I used swapped it over to that one, no hum.

It's rated up to 250W, fuse blew on it maybe 2 or 3 times over the course of using it for about 5 years (usually when powering off and never mid-recording or anything). No biggie, the fuses were about $0.50 each.

 

[38869420]

I googled 388 spec and first result says 120w? Why do you assume it's the transformer? They usually either work or don’t work. Mains voltage transformers have no hum reduction or creation properties? Hums come from ac current leaking? Grounds are 99% guilty in practice.

I’m just trying to figure it out, and I’m not an electronics guy but keen to learn. 60hz hums are usually from power so I thought that’s a place to start.
I’ve since tested it with another step down and it has the same hum, so maybe it’s not that anyway. I’m going to try a different outlet source to see if that helps too. Thanks!

 

[rob aylestone]

Hum is a killer. Remember that the cause is always the mains, so this isn't just the noise it’s also safety. Normally it’s tiny currents, but even tiny current hurt when they involve grounded guitar settings and a live mic. Through your lips!

first thing is to take the 388 and plug it in. Connect headphones only. Does it hum. With just itself and a pair of headphones there should be no hum with a 2 or grounded 3 pin power cable. If it hums in this state, it is faulty. The fault is inside the unit and any messing with extra grounds will not fix the fault, just hide it. If it is hum free, add in your monitor system. Does the hum start? If it does, then the monitor system has the problem, the 388 just reveals it. You progress stage by stage until the hum arrives so this will point to the trouble. Do it systematically, not randomly.