Marantz 2265, 2275, 2250B... P800 Power Supply/Protection PCB Replica

[ton4eff]

I decided to recreate this PCB. Most probably they use this one in other Marantz models, that I'm not aware of... In the first place, I made a clean copy of the schematic (with the vintage look preserved, of course ):

Then, when I was working with the PCB, decided to add an option for installing the higher current Omron LY2-0 relay (10A). I thought it was a good idea at that moment... Or is it? Of course the original MY2-02 (5A) also can be soldered instead. The mechanical dimensions for the relay hole pad's I took from the official datasheets. I hope that they are correct:

The PCB I copied from the Marantz SM and a couple of pictures from the internet. I was very careful with all the sizes, but it would be great if someone can confirm the mechanical dimensions, especially the part with the H804 heat-sink mounting holes:

And a look from the bottom side:

Any suggestions and comments are welcome. Thank you!

 

[Steven Tate]

Great work as usual. This will be a great thing to have available. Can't help with dimensions since I don't have any of those models at this point. I'm sure someone will have one to measure from.

 

[rcs16]

I personally would not design a new pcb using a LY relay. I suggest to use two L5rl types. Ones with 16A contacts

 

[ton4eff]

The original 5A MY2-02 relays still hold strong for 50 years... I just thought that optional LY2-0 with double the current is a good idea, as you can see the footprints of these relays are close enough - no need to change the original design significantly. Which I prefer to keep as close as possible (I'm drawing the copper traces by hand for these ). Triple the current is overkill for this vintage design I think. It would require completely modern 2 layer PCB - too far away from the vintage spirit... . Actually I may leave only the original MY2 for the final PCB version...

 

[Steven Tate]

If memory serves me correcty (not a sure thing), the 2325 had two versions of the relay. Some had the MY2 and some had the LY2. Maybe somebody can correct me if I'm wrong.

 

[ton4eff]

@Steven Tate You are a 100% right! They decided to go with the lower current relay for the latest versions. Most probably for cutting the costs down... Just made a small change in the PCB design - added an option for higher current support with this one layer design on the relay speaker traces. Just in case I decide to keep the higher current LY2 -0 relay option. One just have to apply a thicker layer of solder on this relay traces:

Of course you don't need this, if you never push your amp to it's limits or just use the lower current MY2-0 relay...

 

[Steven Tate]

Nice! I think mine had the LY2 and I had ordered an MY2. I had to wait and chase down an LY2 to restore the board.

 

[EastPoint]

That looks really good! Do you plan to offer them for sale?

 

[ton4eff]

A fellow AK'er was kind enough to send me a high quality scan of his stripped P800 PCB, which is the best option to copying it in the right manner. The distance between the holes for the H804 heatsink appeared to be of by 0.5mm, which I corrected accordingly. (In opposite to some people think, 0.5mm (0.019685") makes a huge difference sometimes, so it must be accurate). He also suggested an option for installing a small heatsink on H801, which I also did by slightly rearranging the position of H802 and H801. We also decided to keep the LY2-0 relay option, because... why not, it doesn't hurt anything in the original design and it is the better performing relay anyway... The models I know so far in which this P800 PCB will fit are: 2235, 2235B, 2250, 2250B, 2265, 2275, 2285. Of course some resistors values should be changed according to the voltages and schematic for each specific model. Al the rest is the same. I'll publish in PDF the final schematic, including the currently available parts for 2275 as an example in my next post. So here is a good candidate for the final P800 version:

@ EastPoint, yes, but anyone can recreate this PCB by the mechanical dimensions I published.

 

[ton4eff]

As I promised, a good quality schematic for 2275 P800 is attached in PDF format.