2SD315de transistor for Marantz

Keith Baran

Keith Baran

Member
Hello all, I'm new here and beginning my first restoration project. I'm trying to find the output transistor for a Marantz 1030. The transistors are labeled "Sanyo 2SD315DE". I've been searching the web for hours and all I come up with are some Chinese generic. I can't even find a cross reference chart with that number.
What am I missing here?
Also, any suggestions on a distributor to buy caps from?
Thanks for any help in advance
Regards
Keith
 
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2sd315 is a to-66 package that is tough to find and very expensive is you can. Only buy these from a reputable source, if you find them, as many out there are fakes. I think I remember seeing someone mention littlediode.com.

Worst case these can be converted to to-220 package devices which fit and are readily available cheap.
 
Hmmm, I forgot about that rebuild. Glad someone knows where those photos are.

I wonder if I still have any of those 2SD315 around.

Capacitors, we get from Mouser.com or Digikey.com.
 
Great stuff thanx, while I have your eyes and ears. I'm realizing this project is a bit larger than my knowledge is. I'm confident in the physical work but have some questions on theory. What type of insulator, would you recommend? I'm reading about mica, sil-pads etc? Sil-pads seem like a good idea but are they best in this situation?What material is used to isolate the legs of the transistor? And for the final and probably the lamest question.. In the picture of the heat sinks, I believe the middle leg of the MJE15032G is the collector, where is it routed? is there a third hole I can't see in that picture? Something else that I just thought, when does all the part replacements begin to change the sound of the amp?
Thanks in advance for any input.
Regards
Keith
 
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Keith Baran said:
I believe the middle leg of the MJE15032G is the collector, where is it routed? is there a third hole I can't see in that picture?
Click to expand...
The tab and the middle leg (the collector of the transistor) are connected together. The electrical connection is through the screw going to the tab. The 2SD315 connects the same way (case is collector)
 
sregor is correct.

You cut off the middle pin on the new transistor. The middle pin and the metal mounting tab are the collector. That is why you need the mica or sil pad insulator.
You can use either mica or sil pads as insulators, it doesn't matter. The sil pads are "cleaner" that you don't need the grease to ensure good heat transfer.
The grease is used to fill the gaps in the hard surfaces to get good transfer. The sil pads are soft and squish to make a good contact for heat transfer.
The screws through the original outputs are insulated through the heat sink and the collector connection is the wire attached to that screw.
The screw used to mount the new transistor is insulated the same way and the wire attached to make the collector connection.

Short pieces of wire insulation or heat shrink are used on the new transistor pins to make safety insulators through the holes in the heat sink.
Strip some wire to get the insulation and cut to length or cut short pieces of shrink wrap for the pins.
 
Hey thanks for all this info. I appreciate all of you taking the time to respond.I'm removing the heat sink, board, this weekend a checking parts against the manual so I can put in an order. I have a 2230 that I love and it's in real good shape but I know sooner or later it will also need work. I got the 1030 for a great price so I will learn on it so hopefully I'll have some skills for the 2230 if needed. I'm sure you will be hearing from me in the next few weeks LOL. Thanks again
Regards
Keith
 
Well, I finally got around to working on the 1030. I removed the output transistors and they all tested good. I want to keep this amp as original as possible so I want to re-install those transistors. As I mentioned earlier my knowledge is limited so I began looking for sil pads for the 2sd315's and I cannot find any. What should I be searching for on Google? "sil pad for the sd315" yields no results. Does anyone have suggestions?
Thanks
Keith
 
You want insulators for the TO-66 device package. Mouser and Digi-Key both stock Keystone 4666, which is a mica insulator. Allied, MCM and Newark have NTE number TP0002, which is silicon rubber.
 
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Does anyone know what the diodes that are attached to the heat sinks are. Value? Designation on the p700 amp board? Marantz number? Mouser number?
Thanks in advance
 
Thermal compensation diodes (SV-3A). Treat them gently, as the leads can easily be broken. They should not be replaced unless you are having some sort of specific problem with bias (idle) current. That, and they are looooong out of production and replacement will be a PITA.
 
Personally I would not pick generic silpads (NTE? meh) over mica/grease; they are not likely to give the same heat transfer performance. I can tell you from several years of analyzing failure modes on car amplifiers with both types of thermal insulator being used that there is a material difference in output device failure rate, in favor of mica/grease.

John
 
I've been working on this 1030, I feel confident I've narrowed the problem to the P700 board. I've been testing caps in circuit, removing them testing again to verify, test the new cap before I install it, then once more when its installed. C708, C710 both indicated open on my Atlas ESR700, I removed them and there was a bunch of white junk all around the base of the caps, and they tested bad. I am extremely lame when trying to read the schematics so would someone explain to me what C708 & C710 purpose is? Could something else in the circuit be taking out these caps?
Thanx in advance for any help.
 
Although they are the same value (47 uF at 50 V), they have two completely different functions. C710 is AC coupling of the feedback from the output to the input transistor H702, and sets the gain (and lowers distortion).
C708 is part of what is called a bootstrap circuit and is used to increase the open loop gain. It makes the resistance R722 seem larger to the rest of the circuit, and increases the gain before feedback is applied. It lowers distortion but has little effect on overall gain.
Polarity is important. The + lead on C710 goes in the same trace as the - lead of C708
And it is very hard to read schematic - Not laid out well for following circuit.
 
Thanks Steve, I barely have enough knowledge to make heads or tales of the schematics. I've read on the forums about discrepancies in the service manual, silk screen, ans schematics. I have one here C715, 716 seem to be installed backwards. The neg side of the cap is on the positive side of the board, according to the silk screen. The schematic of the board in the manual coincides with the actual mounting of the caps. Since this unit did work for several weeks after I bought before it failed my guess is I should install the new caps exactly the way the old caps are installed? correct?

p700 2.jpg p700 1.jpg
 
Keith Baran said:
Thanks Steve, I barely have enough knowledge to make heads or tales of the schematics. I've read on the forums about discrepancies in the service manual, silk screen, ans schematics. I have one here C715, 716 seem to be installed backwards. The neg side of the cap is on the positive side of the board, according to the silk screen. The schematic of the board in the manual coincides with the actual mounting of the caps. Since this unit did work for several weeks after I bought before it failed my guess is I should install the new caps exactly the way the old caps are installed? correct?

View attachment 924297 View attachment 924296
Click to expand...
You are right.
 
I’m finally on the last leg of re-capping the 1030’s P700 amp board, work has kept me away most of the time. I have a few questions I could use some help with

1) There are ten transistors on this board, since this board is a bit of a hassle to take in and out because of the two diodes that are attached to the heat sink, that aren’t made anymore (and don’t want to break) do you think I should replace those transistors since the board is out? If so…

2) This is my first experience with looking up parts on Mouser electronics and I am having a hard time finding equivalent replacements for these transistors, I found H701 & H702, these are 2sc945 O R... what does the O R denote?

I cannot find replacements on Mouser for H705, H706 these are 2sc371 O

Cannot find H707, H708 these are 2sa562 O what does the O denote?

Cannot find H703, H704, these are 2sc853 M.L once again what does M.L denote?

3) Because the two diodes that are attached to the heat sink are old and brittle and I don’t want to handle them too much is it ok to just attach the output transistors to the wires, not use the heat sink just to fire up the unit and verify that everything works? I have a variac with an ammeter and a light bulb tester



Any assistance would be greatly appreciated.

Regards

Keith
 
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