Discussion in 'Marantz Audio' started by ton4eff, Nov 21, 2015.
Lookin' good. Are the wire connection post/pins new or recycled?
Yes, I recycled the pins, I don't know if it is possible at all to find new ones. And today I ordered the transistors, I hope they are genuine this time (from Farnel), and these caps for C725 and C726: click. I hope they will be a good replacement for the missing originals...
very well done, beautiful soldering job!
Making replacements for the missing riser/mount stands for the TO-39 transistors, while waiting for the 1N60's and wondering where to find the source for the original TO-39 heatsinks
You can find OEM 1N60 in old car radio
The diodes from the above link arrived today and they are bad. This was the last semiconductor I bought from ebay! Everything is fake.
@paul_ral, thanks for the suggestion, but I live in the area, where most of the old radios are from Russia, and they didn't use 1N60's...
Sorry to hear about the parts issue, but its great you found them before they put burnt spots in that nice board you made. Excellent work!
The shipping cost from US to EU is little bit too much for a few diodes. Which is very strange, because I've sent to US many letters for just a couple of $. But thanks for the link anyway...
I'll try to figure out something about these stupid germaniums... Maybe, at the end, BAT41 will be the final solution. But it will be like a splinter in my mind.
This work is absolutely amazing. You really should recreate different boards for the popular models like 2270 / 2245 / 2275 etc. They would sell.
Gotta agree. Outstanding work, just awesome! I don't have any Marantz stuff, but now I wish I did!
And it is almost finished, I hope tomorrow I will do the tests:
This is the final revision of the schematic (the parts in red are soldered on the back of the board, as it is on the original), I'm attaching it in pdf format too:
After the tests, I'm starting to recreate the missing heat-sinks for the TO-39 transistors. I'm planning to make a vector image of the originals from my 2230. They look the same to me.
The P700 Board under test:
Everything went smoothly, no surprises... The bias adjusted fine on both channels, after an hour plugged in. It will be adjusted along with the clipping more precise when the board is mounted properly on it's place. And I have to tell you - this thing already SINGS beautiful!
So next to the final step - to39 heat-sinks...
Today I did the vector drawing of the TO-39 Heatsink:
The transistors diameter is 8.25mm and I made the central hole 8.2mm. It will require a little pressure to snap in to the place... Or so I hope... Now I'm starting to search for a local laser cut workshop.
Very cool, glad it came right up.
Call me crazy, but I did a second revision of the heatsink. The reason - this way it's closer to the original, don't you think?
You're crazy! Just kidding ya friend. I'm glad I have an OCD brother in a far away place. Great job. The tiny ribs do increase the cooling surface area so were worth doing.
I agree, great wok. If you didn't have pins to recycle is there another solution you could recommend?
These should do the job:
wow, this is art, amazing job at recreating that board.
The TO-39 heat sinks arrived. I had to expand the central hole to 8.2mm. I sent the drawing only with 3mm drill, because of the laser cut inaccuracy.
And the two of the heat sinks are already mounted on the transistors. They look pretty much as the originals, don't you think?
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