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Help me,Marantz Model 500 diode

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I will take a look tonight if there is anything specific to the 500 that should be considered... But this is a common replacement on other amps, while the 500 tends to be a bit uncommon in some ways.... I did not replace mine, but might once I dig into it a little more. It is just about the only part I did not replace, I just did not like the sight of 3 diodes strung together in my amp if it was not required. Oh well, time to suck it up and charge ahead....

I have a spare amp board that I will remove the diode this evening and put it on the curve tracer for completeness. Might even try temperature testing it.... But I think it will be like a standard SI diode.

Jk
 
jstang said:
I will take a look tonight if there is anything specific to the 500 that should be considered... But this is a common replacement on other amps, while the 500 tends to be a bit uncommon in some ways.... I did not replace mine, but might once I dig into it a little more. It is just about the only part I did not replace, I just did not like the sight of 3 diodes strung together in my amp if it was not required. Oh well, time to suck it up and charge ahead....

I have a spare amp board that I will remove the diode this evening and put it on the curve tracer for completeness. Might even try temperature testing it.... But I think it will be like a standard SI diode.

Jk
Click to expand...

Thanks,
I look forward to the developments.
Imi.
 
Snowed, a foot or more.... Which means digging out and no stereo play time... Tomorrow night will test the diodes....
 
Yes I heard the weather report that there are heavy snowfalls, here good weather and no snow is 10C°. :D
 
Here is the diode trace of the MZ2361. It show a two junction voltage drop, ~ 1.4v. No surprise. The horizontal is the forward voltage.

I do not have the trace for the Sz51066K. The key with that one is the temperature co-efficient. If get a chance to test that one, I will.

I suspect it is typical, however the 500 uses the hot carrier diode FH1100 which has a reverse temp co-efficient....

Be cautious in your crossing and avoid hear say.....

attachment.php
 

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Hi,

Okay
The service plan warns that (mz2361 contact) but does not require that the sz51061k contact.

Thanks,
Imi.
 
Hi,
John

I think 177 will be NTE good Mz2361 instead.
but I have no idea Sz51066K represents the Marantz model 16 Sz51066K smooth diode.
My diode (sz51066k), one of the problem is that one of the leads in the right direction as it is a mark on the glass, close the other direction.
The other diode (sz51066k) 2 is a black strip on the glass were well open, but the Si plates is not there, but the other side. (This is interesting).

Thanks,
Imi.
 
In regards to the questions about the SZ51066K diode, here is a response from John at Instruments Resources about the same diode used in a Model 16 Amplifier:

"The SZ51066 is a three pellet diode with a forward voltage drop of 1.6 - 1.8V @
1mA. You can use 3 switching diodes in series, such as a 1N4148.
Select the diodes to give you this 1.6 - 1.8V. I use TI51 selected.
These give the best temperature characteristics for the amp."
 
ChrisMarantz said:
In regards to the questions about the SZ51066K diode, here is a response from John at Instruments Resources about the same diode used in a Model 16 Amplifier:

"The SZ51066 is a three pellet diode with a forward voltage drop of 1.6 - 1.8V @
1mA. You can use 3 switching diodes in series, such as a 1N4148.
Select the diodes to give you this 1.6 - 1.8V. I use TI51 selected.
These give the best temperature characteristics for the amp."
Click to expand...

Thanks,
Chris
 
Imike16 said:
Hi,
John

I think 177 will be NTE good Mz2361 instead.
but I have no idea Sz51066K represents the Marantz model 16 Sz51066K smooth diode.
My diode (sz51066k), one of the problem is that one of the leads in the right direction as it is a mark on the glass, close the other direction.
The other diode (sz51066k) 2 is a black strip on the glass were well open, but the Si plates is not there, but the other side. (This is interesting).

Thanks,
Imi.
Click to expand...

Picture :D
 

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Mz2361

Forward reference voltage

Min1,24V-Max1,38V
 

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I would use the 2x 1n4148 and not NTE. The NTE is not an exact cross.

The total Voltage drop needs to be about 1.4v for each MZ2361. The NTE does not provide that.

TI51 looks interesting, I will look at that closer. Thanks to Chris for finding that.


The mz2361 on the amp board is just for voltage shift.... But on the heat sink it is used for temp compensation along with the SZ51066. I have not looked at that part of the 500 in a long time. I will try to measure the voltage drop tonight on my "parts unit 500" :D ( not really a parts unit, it needs repair )

Also will try to apply some heat via a heat gun to see the temp co-efficient. Would be helpful to match it more closely.

JohnK


Imike16 said:
Hi,
John

I think 177 will be NTE good Mz2361 instead.
but I have no idea Sz51066K represents the Marantz model 16 Sz51066K smooth diode.
My diode (sz51066k), one of the problem is that one of the leads in the right direction as it is a mark on the glass, close the other direction.
The other diode (sz51066k) 2 is a black strip on the glass were well open, but the Si plates is not there, but the other side. (This is interesting).

Thanks,
Imi.
Click to expand...
 
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