Technics SU-5A Old lady has quiet channel

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Jump to Latest
D

Deafuser

Member
Joined 2012
Hi, I have an old Technics SU-5A amplifier that's got a loss of gain on one channel! I've checked my loudspeakers and source by swapping around the connections, problem remains. I can say all the sliders on this amp produce no crackling and are silent. The loudspeaker connectors are nasty poke the wire in the hole and twist types. They are very creaky when you twist them, I've twisted them back n forth, gently to heavy handed, they're bit like rusty bolts that you free up with oil, except they don't seem to loosen smoothly! Is it possible one is completely corroded? Seems like someone has pushed the balance pot to one side, just a bit!

Whats the best solution without soldering my leads direct, assuming that's the issue?

Thanks
 
Ian Finch

Ian Finch

Member
Joined 2010
Paid Member
As it's now 40 years old and seems to be in poor shape generally, why not a recap? - at least the small value electrolytics in the signal path and using decent quality, low ESR electros or MKP film where it can fit and without absurd prices. My choice would be industry standard Panasonic FC, FM or even FR electros for small values but all reputable manufacturers have at least near equivalents. Use up to twice the original values but make certain the voltage ratings are at least the original voltage or as high as you like above it, if they fit. Watch pin spacings and dimensions to ensure easy fits, though modern electros will be much smaller.

Unfortunately, there is no free online schematic/manual that I could locate but that never stopped me! Done carefully and with attention to polarity, this should not only fix other minor niggles but give the amplifier a whole lot better sound. :)
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Top Bottom