Hi all.
I bought an old (but seemingly quality) Akai reel-to-reel, to digitize my father’s recital tapes from the 60s, 70s, and 80s. I’m plugged in (unbalanced) to a Zoom H4N. I have a 60Hz hum that is quite strong. Here is the catch: the Akai does not have a grounded plug. The hum is faintly present even with the Akai switched off, as long as it is plugged into the wall.
Would the most productive path be to replace the cord with a grounded one, attaching the ground to something appropriate? I’m not afraid to do any soldering, although I am no pro. Are power filters productive for this instead?
I appreciate anyone’s help. Cheers!
you could try reversing the plug on the akai in the wall outlet
going to 3w+g may help or not
could be bad electrolytics in the powersupply of the akai
letting hum get into the preamps
if you play it through your stereo system do you hear hum
do you hear hum if you are connected and not playing
power filter probably not helpful
hum likely to be coming from inside
is the h4 plugged into the same power outlet?
does running it on batteries change the hum level ?
does touching the h4n to the akai reduce the hum
or give you a massive shock of a/c electricity ?
Thanks Whomper; I’ll try to address these.
you could try reversing the plug on the akai in the wall outlet
I will try it; it may be polarized.
could be bad electrolytics in the powersupply of the akai
letting hum get into the preamps
if you play it through your stereo system do you hear hum
Haven’t tried it, but through the Zoom it hums, on battery or wall power. I can’t imagine my amp would make a difference.
do you hear hum if you are connected and not playing
Yes, and even with the Akai off, although it is far less.
is the h4 plugged into the same power outlet?
It makes no difference.
does running it on batteries change the hum level ?
No, it does not.
does touching the h4n to the akai reduce the hum
It changes it a bit, but I can’t get it to go away.
or give you a massive shock of a/c electricity ?
Definitely not.
I appreciate the help.
You might have miswired wall sockets. Older electronics by-passed the metal chassis to one side of the power line. I have an FM tuner which will not work plugged in “upside down.” It’s a two-prong plug.
If the larger of the two prongs (in the US) isn’t ground, then you will have hum whether the electronics is turned on or not. It’s also possible that the tape machine is broken. Older machines can have parts that fail with age and those parts tend to be concentrated in the power system.
I’m looking for a simple, cheap tester that has three lights in it and you get a particular sequence of lights only when the socket is wired right. Manufacturers tend not to recommend these testers because they can give a false positive. But if you get a negative (bad socket), then it’s pretty sure you have a problem.
Here’s a UK version. You can magnify the picture and see the sequence of lights. There are US version for around $5 to $10.
http://www.kenable.co.uk/product_info.php?products_id=2514
http://www.acmehowto.com/howto/homemaintenance/electrical/outlettest.php
Koz