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...
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...