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Marantz 1060 with butchered P700 amp board - questions !

Bert 1100

Bert 1100

Super Member
Hello all !

I bought this 1060 knowing it was defective, for a good price.
It’s quite grimy inside but nice on the outside.
The amp board has been butchered by some previous owner, quite an ugly job.
The other boards luckily look untouched.
After taking the board completely out, I tested the preamp functions, it all works, the controls are not even scratchy…

First I will try to get this board fixed, then the whole amp will be rebuilt and cleaned, I’m quite eager to try out a 1060, never heard one :-)

A few photos :

IMG_1506.jpg IMG_1576.jpg IMG_1572.jpg IMG_1568.jpg IMG_1507.jpg

I will be following Ton4eff’s PDF of his board replica (as found on the AKdatabase) as for which replacements to use. (ton4eff, if you are reading this, thank you !)

I will be renewing all electrolytics, all NTE transistors will come out, some resistors as well (R733 is smoked). Two of the output transistors are shorted, two are fine. I'll replace all 4.
Luckily the SV-3A diodes look like they are fine. And the PCB itself is OK, only some minor trace lifting in a couple of places...

So, a couple of questions :

On my board, H705 H706 H707 H708 are completely missing. Can this be factory, or could it have not worked at all without them ?

H713 and H714 diodes : my board originally has them glued on the heatsinks of H709 and H710 ( no resistors on the back of the board). Can I just put in the 1N4148 with R759 / R760 in parallel and not worry ?

Thanks !
 
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Thanks for the replies !

Just found out more bad stuff.....

H709 - H710 - H711 - H712 (round transistors with the nice heatsinks) are NTE parts :no: .Replacement 2N3440 at mouser are 2$ each, fine....but 2N5416 are at :yikes: 22$ each...no stock at digikey....any other reliable source ?

And my SV-3A diodes look fine but test "open" both polarities, no measurable voltage drop either way......:bye: what are my options ? donor parts ? a string of 3 (which?) diodes cast in epoxy ?
EDIT : I see some descriptions saying the diode function on a normal DMM will not work well to test the SV-3A...so how can I test them ? maybe they are fine ?
Ok, second edit :D, my other DMM (older and cheaper...) shows me a voltage drop of 1.8V for both...:banana: looks like they are fine.

And the 1N60 test fine, all 4....

Anyway, I like a little challenge like this :)
 
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Bert 1100 said:
On my board, H705 H706 H707 H708 are completely missing. Can this be factory, or could it have not worked at all without them ?
Click to expand...

They protect from overload the H001-004. The amp will work without them but it's not recommended.

Bert 1100 said:
H709 - H710 - H711 - H712 (round transistors with the nice heatsinks) are NTE parts :no: .Replacement 2N3440 at mouser are 2$ each, fine....but 2N5416 are at :yikes: 22$ each...no stock at digikey....any other reliable source ?
Click to expand...

You can check these. I bought mine from there.
 
Thanks to Ton4eff I'm taking a fresh start with a new board !
And I got the first batch of parts today :-)
Need to make another order with resistors and caps.
If I keep my orders from abroad between 50 and 62$ I get free shipping and zero import taxes / VAT, nice !
The parts below minus the board are in that price bracket....

IMG_1731.jpg
 
Nice. I wish these new boards were available when I did my second 1060. Its not that the board was in such bad shape but that so many componants were bad it would have just been easier to start with a blank board.
 
At last I got something done on this today...I got all the parts, just need more time...
The only thing that I did not go as smooth as I would have liked is the KSC945 and KSA733, I did not order the "C" for center Collector, so had to do some leg bending....never mind, it'll work just as well.
Elna Silmic II, vishay 1% metal film resistors (MSR25 series) and in a couple of positions Wima films.

IMG_1751.jpg

IMG_1752.jpg

IMG_1753.jpg

last pic just for fun !

IMG_1754.jpg
 
That is just wonderful. I would be interested to hear how it sounds compared to either a stock or restored unit. VERY curious.

How much more do you have to go on that restoration?
 
Airtime, this is my first 1060, and I got this unit with the bad amp board, so I won't be able to say how it sounded before and after....
The rest of the amp is untouched and working, but it will be a couple of weeks till I can test the new amp board in place.
And then onto the other boards and a good cleanup. Another couple of months ? I'm not spending much more than a few hours a week...
 
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That is a nice stereo. Years ago I was watching the series The Sopranos. The character Hesh, who was a music producer, used a 1060 in his office to audition music demos. At that time I remember many posting discussions that confirmed that many people in the "bizz" did use these. Because they had a great sound, small, dependable and not picky with cables, speakers, sources, etc.... Very unlike modern gear today - that I happen to have owned at some point.
 
That's beautiful man.

I was just in my 1070 this morning because the muting relay is trash. I got it to work again by burnishing the contacts with 2000 wet/dry wetted with Deoxit and some aggressive bending of the fingers for better tension, but I will be searching a replacement.

I hope that the community has done the same documentation for the 1070 that apparently has been done for the 1060...!
 
Regarding modern gear, I have the CD6005 and PM8005, they are very nice !
Apparently there are much fewer of the 1070 around....I have the 1090, came later I think. No relay in the 1090.
 
Very good job and nice looking board so far. I'm sure it will sound even better. I see you soldered R759/760 150ohm resistor on top of the board, very thoughtful of you! When I did my board, I was thinking what if replace the bias trimmer whit 120ohm, avoiding paralleling with additional resistor, but wasn't sure if there will be a problem with adjustment. Later, after the tests it appeared that indeed the right bias is in around the center and next time I will put only 120ohm trimmer without the need of R759/760.
 
Thank you for the kind words !
The 150 ohm resistor is in parallel with the 1n4148 bias diode, that's the right way isn't it ? If so I'm not sure it's possible to do without it ?
 
Yes, that's the right way, don't worry. The 150ohm resistor is in parallel with bias trimmer and the diode, but it's not present in all 1060's. Without it however it would be very difficult, even not possible to adjust the bias properly, at least in case with all new parts and modern transistors in the P700 board. That's why I was thinking to replace the trimmer with 120ohm value. Because 150 and 470R in parallel makes 120 right? What do you planning to use instead of 1N60's?
 
The 1n60 from my old board are still good. I get the same voltage drop on all of them.
Ok I see, the 470 ohm variable resistor is also in parallel with the diode and the 150 ohm resistor, so yes choosing a different trim pot should be a good idea...
 
The best case is to use the originals, very difficult to find substitute for the old germaniums. Keep up the good job and enjoy it. That's the most important part of any restoration... ;)
 
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