Marantz model fifteen repair.

John , thank you very much !!!!!
If you could scan all the 1969 pages and service bulletins , it will be very helpfull :bowdown:
 
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John , thank you very much !!!!!
If you could scan all the 1969 pages and service bulletins , it will be very helpfull :bowdown:
Here you are I looked at what was already up and you guys don't seem to have these. hope they help.
-john
 

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Here you are I looked at what was already up and you guys don't seem to have these. hope they help.
-john
This is amazing! I just finished renovating my model 15, but these are great to verify that I did it correctly! Thanks!
 
Working on one of these now.

I've used a 2N5401 to replace DTM-6.

KSA992FBU (Digikey KSA992FBU-ND) Work extremely well, too.
Just match them with a DMM's hfe function and they'll be centre-slot-on-balance-control.
Nice thing about modern transistor manufacturing, is grabbing any two at random from the same lot number will likely be within 1% of matched, anyway.

Working on a foolproof Q107. Will let you all know.
 
Hi Folks,

PN2222 is good for Q107 :)

The higher hfe makes it neccessary to bring her up on a VARIAC and adjust the bias as you go.

Also, that horribly unreliable bias diode pack can be replaced with 3 x 1N4148 in series. Change it out if you replace Q107. Cover the diodes and transistor in heatsink goop for good thermal conductivity to the case.

Cheers!
 
Hi Folks,

PN2222 is good for Q107 :)

The higher hfe makes it neccessary to bring her up on a VARIAC and adjust the bias as you go.

Also, that horribly unreliable bias diode pack can be replaced with 3 x 1N4148 in series. Change it out if you replace Q107. Cover the diodes and transistor in heatsink goop for good thermal conductivity to the case.

Cheers!

Anyone have a part number and supplier of the overload lamps?
 
The part number for those is #1134 lamp , the originals are General electric but you can use other brands .
 
I was attempting to contact John at Marantzserices but emails haven’t been returned. Anyone here know of his service and how to contact him?
 
I really appreciated this thread. I am going through a Model 15 and have a bad CR104. For testing purposes at least I replaced it with a 1N4148 200ma 100v. I also have a 1n4007 but thought it may be overkill. What would be a good substitute? Thanks
 
I am on the 'second half' (amp) of a Model 15 recap, and wondering how many of the old discussion group are still around here, and perhaps listening to a Model 15 still? I started hearing crappy sound as I started to turn the volume up and really didn't know why except to pull it offline. Wondered about the one vs. two output thing and the 1969 stuff will really help :). Just found a couple burned resistors, one broken in half feeding the base(s) of one of those outputs from the drivers . . . recp kit from captainfantastic on ebay had too many 333K's .033 and not enough 474's .47's for this amp
 
I didn’t receive a response to my post, but having spent a lot of energy on the fifteen I am continuing to monitor the thread.
 
Today I made a new diode pack to replace CR110 and put in a new BC550 to replace Q107. I also found an iffy connection on CR111. The amp now has bias. It is almost at max on R30 but seem to be holding. I will run it for a few hours tomorrow and see what happens.

Tony
 
Only six years in between. Not bad?

Tony

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IMG_8100.JPG
 
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I'm also restoring a 3rd-revision Model 15 (with the relay, and with no TO-33s on the heatsinks). I think it's useful to get a list of known transistor substitutes. So far, we have:
Q101, Q102, & Q103; originally DTM6; substitute 2N5401 (closely matched for Q102 and Q103).
Q108 & Q112; originally DTM11; substitute NTE291
Q102 & Q111; originally DTM12; substitute NTE292
Q110; originally DTM14; substitute MJ15004
Q113; originally DTM13; substitute MJ15003
That leaves:
Q104; originally DTM9; substitute ??
Q105 & Q106; originally DTM8; substitute ??
Q107; originally DTM10; substitute ??

If anyone knows any good substitutes for Q104 through Q107, please reply.

I traced the gainstage amp board to ID the components, fixing three errors in the service manual, which had Q102 and Q103 swapped, and misidentified Q105 as Q107. Here's my result:
https://dl.dropboxusercontent.com/u/37073121/Marantz/AmpBoard.pdf

This is the first later-model Model 15 I've worked on. Are the missing Q109 and Q112 TO33's from the heatsinks replaced with something else elsewhere? Are they on the current limiter board?

I'd also welcome sources for replacements for the big 5450uF caps, C15 and C21.

Does anyone have pictures and part info on the 300 board of the gen three 14/15?
 

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I am looking for a good replacement for diode CR112 (MR1120). I have seen posts of people using either diode ERD24-02. Anyone know which set is the best replacement?

Chu
 
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