Installation of a replacement transformer for the oscilloscope of the Model 18.

RV59

Active Member
I open this thread for those who have problems with the voltages
required to operate the oscilloscope on the marantz Model 18.
The defective -500V is a recurrent problem on the transformers of this Model,
but if you are lucky that the other voltages are correct,
it is possible to add a small substitute transformer so that the oscilloscope will work again.

I made the modification myself on two Model 18s, a friend also made it here in France,
and Calman46 of Audiokarma made the modification as well.

However, the operation requires a minimum of technical knowledge
as well as the necessary skills for assembly, wiring and welding of the whole unit.
I am not responsible for any malfunctions that may result from improper wiring.

First you need to buy the little transformer here:
https://www.audiophonics.fr/en/elec...om-toroidal-transformer-all-power-p-3675.html

And this is exactly what you need to order:

-----------------------
Quantity : 1
Profil : Standard
Total power: 15VA
Primary : 110V *
Secondary :
1x325V 0,03A (10VA)
1x5,6V 0,9A (5VA)
(+ electrostatic screen)
-----------------------

* or 115, 220, 230 depends on the country where you live and the voltage you have in your plugs.

Count at least 1 month to receive it.
It's very important to respect all these tensions, it took me a long time to determine their exact values.

Here is a little folder with all the instructions:
https://www.fichier-zip.com/2018/02/16/transfoht18/transfoht18.zip

Let me knows if you have any questions...
 
No, it only takes some technical knowledge.
The main difficulties were finding someone to make custom transformers,
and what output voltages to choose.

What continuous tensions do you get? (-500 & 6.3)
 
I open this thread for those who have problems with the voltages
required to operate the oscilloscope on the marantz Model 18.
The defective -500V is a recurrent problem on the transformers of this Model,
but if you are lucky that the other voltages are correct,
it is possible to add a small substitute transformer so that the oscilloscope will work again.

I made the modification myself on two Model 18s, a friend also made it here in France,
and Calman46 of Audiokarma made the modification as well.

However, the operation requires a minimum of technical knowledge
as well as the necessary skills for assembly, wiring and welding of the whole unit.
I am not responsible for any malfunctions that may result from improper wiring.

First you need to buy the little transformer here:
https://www.audiophonics.fr/en/elec...om-toroidal-transformer-all-power-p-3675.html

And this is exactly what you need to order:

-----------------------
Quantity : 1
Profil : Standard
Total power: 15VA
Primary : 110V *
Secondary :
1x325V 0,03A (10VA)
1x5,6V 0,9A (5VA)
(+ electrostatic screen)
-----------------------

* or 115, 220, 230 depends on the country where you live and the voltage you have in your plugs.

Count at least 1 month to receive it.
It's very important to respect all these tensions, it took me a long time to determine their exact values.

Here is a little folder with all the instructions:
https://www.fichier-zip.com/2018/02/16/transfoht18/transfoht18.zip

Let me knows if you have any questions...
Hell YA!! Thank You! Been looking for this fix for a long time.
 
I open this thread for those who have problems with the voltages
required to operate the oscilloscope on the marantz Model 18.
The defective -500V is a recurrent problem on the transformers of this Model,
but if you are lucky that the other voltages are correct,
it is possible to add a small substitute transformer so that the oscilloscope will work again.

I made the modification myself on two Model 18s, a friend also made it here in France,
and Calman46 of Audiokarma made the modification as well.

However, the operation requires a minimum of technical knowledge
as well as the necessary skills for assembly, wiring and welding of the whole unit.
I am not responsible for any malfunctions that may result from improper wiring.

First you need to buy the little transformer here:
https://www.audiophonics.fr/en/elec...om-toroidal-transformer-all-power-p-3675.html

And this is exactly what you need to order:

-----------------------
Quantity : 1
Profil : Standard
Total power: 15VA
Primary : 110V *
Secondary :
1x325V 0,03A (10VA)
1x5,6V 0,9A (5VA)
(+ electrostatic screen)
-----------------------

* or 115, 220, 230 depends on the country where you live and the voltage you have in your plugs.

Count at least 1 month to receive it.
It's very important to respect all these tensions, it took me a long time to determine their exact values.

Here is a little folder with all the instructions:
https://www.fichier-zip.com/2018/02/16/transfoht18/transfoht18.zip

Let me knows if you have any questions...

Hello
i have the same problem with my Marantz 19 : no 500v !
can't you give me the file for repair it ?
many thanks
BR
Gérald
 
I know this is an old thread awesome work, is it possible to get a copy of the instructions? the orginal link has gone dead ? my email is fmajewsk@gmail.com if someone could be so kind. :)
 
Back
Top Bottom