Marantz PC board question / observation

[Richs_Trains]

As I posted before I have a 2220b with a nasty power amp board, the foils were mostly non-existent from the factory and all of the components were install with the pins bent against the PC board. I purchased a used power amp board for this unit because once I worked on the old board I could not get it to bias. Well the new/used board is just beautiful, all the foils are full and the components are straight in and trimmed right to the PC. My question, why so much difference in two boards from the same model, was there a time period when the manufacturing was below par, were all the 2220b's made in Japan? When I pull the board completely out of the unit, I will post a picture of them side by side. Also, I notice the outputs in the well made board say Marantz on them, the lousy board has the same #'s but no 'Marantz' stamped on it. Just curious .... Thanks for any insight. Rich

Here's the new/used board and it was a joy to work on with my new vacuum solder station, zip, zip, zip.

 

[petehall347]

maybe is a board someone made and not too good .. college project or something ..
did it have same components installed ?

 

[Richs_Trains]

Same components, the layout of the foil is somewhat different on the lousy board and and there are places where it looks like the foil was punched with a hole punch to break the connection and paces where the leg of the component is used to make the connection, wierd. I'm thinking this was part of a batch of 2220's and Marantz turned them into 2220B's by making modifications on the existing boards instead of installing new 2220b boards. Possible? yes, no, maybe?

 

[Richs_Trains]

Okay, here is the "bad" board. Notice the component legs being used to make the connection. I really think this was from the factory and a makeshift job of turning a 2220 into a 2220B. I would like to compare the board to a 2220 , as it is different than the 2220B board I just got. The new/used board has no punch outs on the foils and no jumpers and all the components are mounted without the legs bent against the PC.

 

[Richs_Trains]

Here's the component side. The green is the new/used and the tan the old nasty.

 

[Steven Tate]

I just recapped a 2220, and I don't think that is a 2220 board. I don't remember any kind of relay on the power amp board.

 

[Richs_Trains]

If you look at the back of the boards, you can plainly see where the relay is supposed to be on the new/used green board, on the tan board, it almost looks like the relay was forced onto it, there is no pin layout designed for it, It could still be a 2220 board built to work in a 2220B with Mickey Mouse connections.

 

[Leestereo]

The 2220 has a capacitor coupled output stage, hence no relay. The 2220B output stage is direct coupled and uses a relay. I think that the OP has examples of an early and late production 2220B board; the early variant appears to have been poorly manufactured.