Marantz soldering changes between 1975 and 1976

[marcpitt]

Just a quick post to share the stark difference in soldering processes between 1975 and 1976. I have currently opened both of my 2270's one from each of the years. Here are pictures of the back of the power supply boards where you can see the clear difference in soldering. All the boards in the units are like this where the earlier one clearly has component leads bent over and large soldering "puddles" (for lack of better words) where the '76 is more cleanly wave soldered. Note that the newer one was also rebuilt so several of the components were replaced. Also just noticing the blue and grey wires are opposite on these two. hmmm.

 

[rBuckner]

Many of us will tell you we hate the clenched over leads. I'm guessing they did that so parts wouldn't pop out during the wave soldering process. You need to switch the blue and gray wires on the left one. If the amp blows in such a way as to put rail voltage out, the relay sensing circuit won't get that and click off. Goodbye Mr. Speaker!

 

[tarior]

That first pic doesn't look like factory work to me.

 

[marcpitt]

Thanks for pointing that out. I actually didn’t touch the left one, but it does look like the relay was replaced at some point. I didn’t notice the difference until posting the pictures and then wondered which one was correct. I planned to look it up but thanks to this community don’t have to.

 

[marcpitt]

That first pic doesn't look like factory work to me.

Well the first one clearly looks to have had the relay replaced. But all the other capacitors and components really appear to be original. The second one I completely rebuilt so all capacitors, diodes, transistors, etc were replaced and that is my soldering mess

 

[tarior]

Well the first one clearly looks to have had the relay replaced. But all the other capacitors and components really appear to be original. The second one I completely rebuilt so all capacitors, diodes, transistors, etc were replaced and that is my soldering mess

That first one never would have gotten past QC at the factory, so it's a safe bet that the relay has been removed and reinstalled, or something. The second one doesn't look factory either, but it's at least a reasonably clean job.