AKAI 370D noise

  • Thread starter Thread starter robin watson
  • Start date Start date
R

robin watson

New member
I've noticed a curious output noise at playback that sounds a little like LP surface crackle, and even occurs while the transport is stopped if I move the tension arms on either side or manually turn the reels.

Anyone heard of this kind of problem?

Robin.
 
robin watson said:
I've noticed a curious output noise at playback that sounds a little like LP surface crackle, and even occurs while the transport is stopped if I move the tension arms on either side or manually turn the reels.
Click to expand...
Sounds like some kind of instability in the playback amp. Check the caps.
 
Checked the caps. They are all there, all 48 of 'em.

At least they're common values. I assume you're talking about the boards at the bottom of the unit.

Finding replacements for those 3-section power supply caps might be a different story though.
 
robin watson said:
At least they're common values. I assume you're talking about the boards at the bottom of the unit.
Click to expand...
I'm not familiar with that model, but I do have a GX265D and there's probably not a huge amount of difference. At the bottom of the 265 there are two PCBs, one holding the record amps, one the playback. I'm guessing your problem relates to some kind of instability in the playback section. Replacing all the caps is probably overkill, but it would be a good idea to grab the schematic and try to identify which ones are likely to go noisy.

Sorry I can't really be more specific without details on this model - its a starting point!

Cya
Andrew
 
Thanks. FYI, there are actually 4 boards on the GX370D, which I assume are the individual rec and playback amps for the 2 channels.

35 year old technology - the PCBs look almost like they were etched by hand, covered in some kind of varnish and the soldering in places looks like bird shit!
 
robin watson said:
35 year old technology - the PCBs look almost like they were etched by hand, covered in some kind of varnish and the soldering in places looks like bird shit!
Click to expand...
If the soldering looks rough then it might be a good idea just to run over it - your problem doesn't sound like a dry joint but its not going to hurt and may just help with other issues!

Cya
Andrew
 
I wonder if those resistors are carbon composition?

Actually, the soldering's not THAT bad, but certainly in places it's clearly factory hand-soldered on a Friday afternoon! Incredible the amount of manual labour that must have gone into putting one of these old machines together.

These days it's all preformed parts, flow-soldered circuit boards, ribbon cables....
 
You must log in or register to reply here.
Back
Top